Chapter 1 — Exposition of Chapter 1 — Commentary on Boethius's De Trinitate

Chapter 1 — Exposition of Chapter 1

Hereupon, after the Preface, Boethius begins his treatise De Trinitate personarum, et unitate divinae essentiae: and this book is divided into two parts.

First, he discusses those things which pertain to the unity of the divine essence, making opposition the Arians.

Second, he treats of those things which pertain to the Trinity of persons, in opposition to Sabellius, beginning: in as many ways as things are the same, in the same number of ways they are said to be diverse.

The first part is also divided into two sections.

In the first, he proposes the doctrine of the Catholic faith in regard to the unity of the divine essence (ch. 1).

Second, he investigates the truth of the doctrine proposed when he says: therefore (ch. 2).

In the first section he treats of two things.

First, he represents the condition of that faith whose doctrine he intends to explain.

Second, he sets forth the doctrine of the faith he has described concerning this proposition, saying: the belief of this religion concerning the Trinity.

He describes this religion in a twofold manner, namely, by comparison with heretical cults, which it excels, and also in its own name since it is called catholic or universal.

He says, therefore, that there are many, that is, many sects of diverse heresies, who usurp, since they unduly attribute to themselves the dignity of the Christian religion, that is, the honor which ought to be paid to it: namely, that all others should be subject to it, according to 1 John 5:4: this is the victory that overcomes the world, our faith. Or, again, they claim the dignity which belongs to the Christian religion in that it manifests the glory of God by believing those truths which have been divinely revealed.

But that form of faith has supreme authority, and has it exclusively. Here he adds the two things that make it distinct both according to truth and according to reputation. Now according to the truth of the matter, heretics are not Christians, since they cut themselves off from the teachings of Christ, and in this respect the Catholic faith alone is valid. But according to appearances and in the opinion of men, heretics are called Christians because they do indeed still, at least in word, confess the name of Christ; and according to this aspect, the Catholic faith is not the only one, but holds the place of greater authority. That this religion is the more common and the more widely diffused is understood when he says, which is called catholic or universal. Now this is the same thing; for “catholic” in the Greek, means the same as the Latin “universal.”

For the use of this name, he assigns two reasons, saying: on account of the precepts of its universal rules, for the precepts which the Catholic religion sets forth are not to be observed by one race alone, but by all: and in this respect it differs especially from the Law of Moses which gave precepts to one people alone. Likewise even individual heresies propose rules that are accommodated to their own members only; while the Catholic faith, having the care of all, gives its precepts to all: not to the unmarried alone, as do the Manichaeans, but also to the married; not to the innocent alone, as do the Novatians, but to sinners as well, for whom that sect would make salvation impossible. Wherefore he adds: the authority of this religion is evident because of its universal rules, on account of which all ought to be subject to it. Or they may be called universal rules since there is in them no falsity or any admixture of evil, neither in any essential article or accidentally.

Then he adds another reason, saying: because the worship in which they are expressed has spread throughout the world, a thing which is evidently in accord with that saying of Psalm 18:5: their sound has gone forth into all the earth: and their words unto the ends of the world.

Hereupon he next sets forth the doctrine of the Catholic faith concerning the question proposed: the belief of this religion concerning the Trinity. Concerning this, he does three things.

First, he presents the teaching of the Catholic faith on the unity of the Trinity.

Second, the reason for this opinion: the principle of this unity.

Third, he shows the fitness of the reason, saying: now the essence of plurality.

Moreover, he proposes the opinion of Catholic faith in a certain argumentative form, because faith is called the evidence of things that appear not (Heb 11:1). In the same argument, indeed, from the fact that divinity is attributed equally to each of the persons, he concludes that of all three the name God is predicated not plurally, as taken together, but individually.

Next he assigns the reason for this belief.

First, he states the reason,

and second, he explains it by its contrary where he says: difference cannot be avoided by those who add to or take from the Unity.

Therefore he says: the nature of their unity is such that there is no difference, namely, the unity of Deity in the three persons, as confessed by the Catholic faith. From this the conclusion following upon the foregoing words is that Deity without difference is attributed to each of the three persons.

And this reasoning he explains by its contrary saying: difference cannot be avoided by those who add to or take from the Unity (of the Deity): that is, who hold that one person is greater or less than the others, as the Arians, who make the Father greater than the Son. Wherefore he continues: as for instance the Arians, who by graduating the Trinity, break it up; that is, by graduating the Trinity according to dignity, since they make the Son subject to the Father, and the Holy Spirit to both Father and Son, and so convert it to plurality; that is, produce diversity by dividing the Deity among the persons. For from division there follows plurality. Conversely, Catholics who confess an equality of the persons, an equality without difference, make profession of consequent Unity.

Next, he shows that the foregoing reasoning is valid, saying: for the essence of plurality is otherness. And this is divided in two parts.

First, he points out the necessity possessed by this reasoning.

Second, what in the demonstration itself had been supposed is made clear: in fact, the difference between three or more things lies in genus or species or number.

Regarding the first point he does two things.

First, he shows that otherness is the principle of plurality, understanding by “otherness” any difference by which things can be constituted among themselves as other. And he prefers to say “otherness” rather than “separateness” because not only substantial differences constitute plurality, since they make another thing, but accidental differences also constitute plurality, since they make for otherness: they make a thing other. Now otherness follows upon separateness; but the converse is not true. And the reason for the deduction of the Arians follows from this supposition. For if otherness is the principle of plurality, and positing a cause posits its effect, then supposing in them that otherness is by augmentation and diminution, plurality of divinity would follow.

Second, he proposes that otherness is properly the principle of plurality, because, except for it, understanding of plurality is impossible; and according to this principle is the Catholic explanation of divine unity: for if a proper cause is taken away, so also is the effect. If, therefore, in the three persons there is no otherness of Deity, there will be no plurality, but unity.

Next, he proves what was supposed, namely, that otherness is the proper principle of plurality, when he says, in fact, the difference between three or more things. And the reason is that in all things that differ in genus or species or number, there is some otherness or difference which is the cause of plurality or, diversity. But all plural things, whether three or more, are diverse either generically, specifically, or numerically; therefore some kind of otherness is the principle of all plurality. In explaining this, he does three things.

First, he states the minor;

second, its proof, beginning, in as many ways as things are the same, in the same number of ways they are said to be diverse.

This is [the demonstration of] the proof: in as many ways as things are said to be the same, in the same number of ways they are said to be diverse.

But things are said to be the same in three ways, namely, in genus, species, and number.

Therefore, things are said to be diverse in the same number of ways.

The first is supposed from what is stated in Topics, 1, that as much is said of one of two opposites as is said of the other: (Aristotle, Topics, 1.15, 106b13–15.) and from the saying of Metaphysics, 10, that the same and different are opposites. (Aristotle, Metaphysics, 10.4, 1054b22; 5.12, 1018a12.) Second, it is made clear by examples and supposes what is said in Topics, 1. (Aristotle, Topics, 1.7, 103a7–14.)

Third, he proves the major in regard to that point which might be held in doubt, saying: but a variety of accidents brings about numerical difference. That the diversity of those things which are diverse according to genus or species must have as principle some otherness, is evident from the name itself. For from the fact that things are of different genera it is evident that a different, or other, genus belongs to each; and if they differ in species, it is because they are contained under other species. But in the case of things which are said to be diverse numerically, it is not evident from the name itself that otherness is the principle of plurality. Furthermore, it might rather appear to be the converse according to the name and that plurality, which is designated by number, might be the principle of diversity, since things numerically different are different according to the same name employed when difference is by genus or species.

Therefore, to prove the major of his syllogism, he shows that this difference by which things are said to differ numerically is produced by a certain kind of otherness or variety. He proves this by the fact that in three men who agree in genus and species, but who differ numerically, there is found accidental otherness, just as between man and ox there is specific otherness and between man and stone generic otherness. Wherefore, as man and ox differ specifically, so two men differ accidentally.

And because some one might be able to say that accidental variety is not the cause of numerical plurality since, if accidents are done away with-either removed actually, as when separable, or by the mind and in thought, as when inseparable—substance still remains, since accident is that which can be present or absent without corruption of the substance: therefore he forestalls this objection, saying that, although all accidents might indeed be separated from a substance by the mind, nevertheless the diversity of one accident could in no way, even by the mind, be separated from diverse individuals, namely, diversity of place. For two individuals cannot be in the same place either according to fact or according to any fiction of the mind, since this cannot be understood or imagined. Wherefore he concludes that from the fact that men are plural in number they are plural by reason of accidents; that is, they are for this reason diversified.

And with this is terminated the teaching of this part of the treatise.

The question here is twofold.

First, there is consideration of those things that pertain to the communion of faith:

second, of those that pertain to the cause of plurality.

Question 3

Concerning those things that pertain to the knowledge possessed by faith

In regard to the first, four questions are asked.

Whether faith is necessary for mankind.
How faith is related to religion.
Whether the true faith is aptly called Catholic or universal.
Whether this is the confession of the true faith: that Father, Son, and Holy Spirit each is God, and that the three are one God without any difference owing to inequality.

Article 1

Whether faith is necessary for mankind

Obj. 1: It seems that faith should not be considered necessary for mankind. As is said in Ecclesiastes 7:1, what needeth a man to seek things that are above him? This is to say, there is no need. But those things that are believed by faith are above man, as exceeding his reason; otherwise his reason, which is the cause of science, would suffice. Therefore it was not necessary for man that, over and above the truths of reason, he should be taught those of faith.

Obj. 2: God established human nature as something perfect when he created it. The works of God are perfect (Duet 32:4). But from the ability bestowed upon the human mind according to its original condition, man cannot attain to those things which must be known by faith; otherwise he would be able to possess scientific knowledge of them, a knowledge which is caused by the fact that conclusions are resolved into naturally known principles. Since, therefore, a thing is called perfect if it lacks nothing that it ought to possess, as is said in Metaphysics, 5, it seems that man does not require faith. (Aristotle, Metaphysics, 5.18, 1021b13–17.)

Obj. 3: Every wise man makes choice of the shorter way to reach a goal: but it would appear exceedingly difficult for a creature to believe truths which are above reason and, in the case of men, extremely dangerous, since many fall away from the state of salvation because they do not believe; therefore, it seems that God, who is all-wise, ought not to have established faith as the way of salvation for men.

Obj. 4: Whenever there is acceptance of knowledge without judgment, the road to error is easy; but we have in ourselves no ability by which we are able to judge of the things which we accept by faith, since our natural judgment does not extend to truths of this kind, as they exceed reason; therefore evidently the road to error is an easy one for us, and so it would appear rather harmful than useful for man that he should be directed to God by the way of faith.

Obj. 5: As Dionysius says, it is an evil for man to exist apart from reason; (Dionysius, The Divine Names, c. 4, n. 32 (PG 3:733A).) but man in adhering to faith departs from reason, and in this he is even accustomed to despise reason; therefore it seems that such a way is evil for men.

On the contrary, without faith it is impossible to please God (Heb 11:6); but it is supremely necessary for man that he be pleasing to God, since otherwise he can neither do nor possess any good; therefore faith is most necessary for man.

Moreover, it is most necessary for man to know the truth, since beatitude is joy in knowing the truth, as Augustine says; (Augustine, Confessions, 10.23.33 (PL 32:793; CCL 27:173; CSEL 33:252).) but faith establishes believers in truth and establishes truth in them, as Dionysius says (On the Divine Names, 7); (Dionysius, The Divine Names, c. 7, n. 4 (PG 3:872C).) therefore faith is most necessary for man.

Moreover, that without which human society cannot be conserved is especially necessary for man, since man is a political animal (Ethics, 8); (Aristotle, Ethics, 8.12, 1162a17–18.) but without faith human society cannot be preserved, since it is requisite that one man believe in the promises of another and in his testimony and the like, for this is necessary if they are to live together; therefore faith is most necessary for mankind.

I answer that it must be said that faith has something in common with opinion, and something in common with knowledge and understanding, by reason of which it holds a position midway between opinion and understanding or science, according to Hugh of St. Victor. (Hugh of St. Victor, On the Sacraments, I p.X c.2 (PL 176:330 C).) In common with understanding and knowledge, it possesses certain and fixed assent; and in this it differs from opinion, which accepts one of two opposites, though with fear that the other may be true, and on account of this doubt it fluctuates between two contraries. But, in common with opinion, faith is concerned with things that are not naturally possible to our understanding, and in this respect it differs from science and intellection.

That a thing should not be apparent to human understanding can arise for two reasons, as is said in Metaphysics, 2: namely, because of lack of knowability in things themselves, and because of lack of intellectual ability on our part. (Aristotle, Metaphysics, 2.1, 993b7–9.)

It may be due to lack on the part of things, as in the case of singular and contingent things which are remote from our senses, like the deeds and words and thoughts of men; for these are of such a nature that they may be known to one man, but unknown to others. And since among men dwelling together one man should deal with another as with himself in what he is not self-sufficient, therefore it is needful that he be able to stand with as much certainty on what another knows, but of which he himself is ignorant, as upon the truths which he himself knows. Hence it is that in human society faith is necessary in order that one man give credence to the words of another, and this is the foundation of justice, as Cicero says in his book, De officiis. (Cicero, On Duties, I c. 7 n. 23.) Hence also it is that no lie is without sin, since every lie derogates from that faith which is so necessary.

The truth of things may also not be evident because of defect on our part, as in the case of divine and necessary things which, according to their own nature, are most knowable. Wherefore, to understand them, we are not capable of immediate intellection, from the very beginning, since it is in accordance with our nature to attain from things less knowable and posterior in themselves, to knowledge of those that are themselves more knowable and prior.

But since from none of those things that we know last do we have any knowledge of those that we know first, it is needful for us even at first to have some notion of those things that are most knowable in themselves; but this cannot be except by believing. And this is evident even in the order of the sciences; since that science which is concerned with highest causes, namely, metaphysics, comes last in human knowledge; yet in sciences that are preambles to it there must be supposed certain truths which only in it are more fully revealed; therefore every science has some suppositions that must be believed in order to cafty on the process of learning.

Since, therefore, the end of human life is beatitude, which consists in the full cognition of divine truths, it is necessary that human life be directed to this beatitude by an initial possession of divine truths by faith, truths which man can hope to know fully in the ultimate state of human perfection.

Certain of these truths that must be known can be attained by reason even in this life: however, although knowledge of them is possible and even possessed by certain men, nevertheless faith is necessary for five reasons, which Rabbi Moses enumerates. (Moses Maimonides, A Guide for the Perplexed, I c. 33 (ed. Justiniani, f. 12 v).)

First, on account of the depth and subtlety of the matter, by which divine truths are hidden from human understanding. Therefore, lest any man be without some knowledge of them, provision is made that through faith, at least, he know divine truths. Therefore, in Ecclesiastes 7:25 it is said: it is a great depth, who shall find it out?

Second, on account of the weakness of the human intellect from the beginning. For perfection of knowledge does not belong to the human intellect except at the end; therefore, that it should at no time lack a knowledge of God, it requires faith by which it may accept divine truths from the very beginning.

Third, because of the many preambles that are required for a knowledge of God according to reason. For this there is needed knowledge of almost all the sciences, since cognition of divine things is the end of them all. But few indeed would comprehend these preambulatory truths or investigate them completely. Therefore, lest large numbers of men should be left without knowledge of divine things, the way of faith has been provided by God himself.

Fourth, many men on account of their natural constitution are unfitted for perfect intellectual investigation according to reason; therefore, that these might not lack knowledge of divine truths, the way of faith has been provided.

Fifth, because of numerous occupations with which men are busied, it would be impossible for all of them to discover, by way of reason, necessary truth in regard to God, and on this account the way of faith has been established, both as regards things that might in some way be known and as regards those that required revelation in order that they be believed.

But in the case of certain divine truths, for a complete understanding of them the human mind in no way suffices, but full knowledge of them is to be awaited in that future life when there will be complete beatitude: such is the truth of the Trinity and the unity of one God; and man is led to knowledge of this, not in accordance with anything due his nature, but by divine grace alone. Therefore it is necessary that, for a perfection of knowledge of this kind, certain suppositions be proposed which must be believed at first, and from these one is directed into full cognition of those truths which at the outset he held on faith, even as in other sciences also, as has been said. Hence in Isaiah 7:9 it is said, according to one translation: unless thou hadst believed, thou wouldst not understand. And suppositions of this sort are those that must be believed by all, since in this life they are neither known nor understood by any one.

Reply Obj. 1: It may be said: although matters of faith considered according to man’s natural powers are above him, they are not above man when he is illuminated by divine light; hence it is not necessary for man that he seek out such truths by his own power, but it is necessary for him to know them by divine revelation.

Reply Obj. 2: It may be said: God, in the first creation of things, established man as perfect in accordance with the perfection of his nature, and this consisted in the fact that man had all things due to his nature. But over and above that due to nature there were added afterward to the human race certain other perfections owing their source to divine grace alone, and among these was faith, as is evident from Ephesians 2:8, where it is said of faith that it is the gift of God.

Reply Obj. 3: It may be said: for anyone striving to attain beatitude it is necessary to know in what he ought to seek this beatitude, and in what way. But this, indeed, can be done in no easier way than through faith, since investigation by reason cannot attain to such knowledge except after a previous knowledge of many other things, things not easy to know. Nor can one attain to such knowledge without danger, since human investigation, because of the weakness of our intellect, is prone to error; and this is clearly shown by reference to those philosophers who, in attempting to find out the purpose of human life by way of reason, did not find in themselves the true method, and so fell into many and shameful errors; and so greatly did they differ among themselves that scarcely two or three among them all were in agreement on any one question; yet, on the other hand, we see that by faith many peoples are brought to the acceptance of one common belief.

Reply Obj. 4: It may be said: whenever there is acceptance of a truth, by whatever mode of assent, there must be something which moves the mind to assent: just as the naturally possessed light of the intellect causes assent to first principles, and the truth of those first principles causes assent to conclusions made from them; while in other ways we assent to things of which we have an opinion, though, if motives were a little stronger, they would incline us to belief, in so far as faith is said to be opinion. But that which inclines the mind to assent to the first principles of understanding or to conclusions known from these principles is a sufficient induction which forces assent, and is sufficient to judge of those things to which the mind gives its assent.

On the other hand, whatever inclines one to form an opinion, even though with a good amount of conviction, is not that sufficient form of induction whereby assent is forced, nor by reason of it can there be perfect judgment of the things to which assent is given. Therefore also in faith by which we believe in God, not only is there acceptance of the truths to which we give assent, but also something which inclines us to that assent; and this is the special light which is the habit of faith, divinely infused into the human mind. This, moreover, is more sufficient for inducing belief than any demonstration, for, though from the latter no false conclusions are reached, still man frequently errs in this: that he thinks something is a demonstration which is not.

The light of faith is also more sufficient than the natural light of reason by which we assent to first principles, since this natural light is often impeded by bodily infirmity, as is evident in the case of the insane. But the light of faith, which is, as it were, a kind of impression of the First Truth in our minds, cannot fail, any more than God can deceive us or lie; therefore this light suffices for making judgment. This habit of faith, nevertheless, does not move us by way of intellectual understanding, but more by way of the will; therefore it does not make us comprehend those truths which we believe, nor does it force assent, but it causes us to assent to them voluntarily.

And thus it is evident that faith comes in two ways: namely, from God by reason of the interior light which induces assent, and also by reason of those truths which are proposed exteriorly and take their source from divine revelation. These latter are related to the knowledge which is of faith as things known by the senses are to knowledge of first principles, because in both cases there is a certain determination given to cognition. Therefore, as cognition of first principles is received by way of sense experience, and yet the light by which those principles are known is innate, so faith comes by way of hearing, and yet the habit of faith is infused.

Reply Obj. 5: It may be said: to live in accordance with reason is the good of man inasmuch as he is man. Now, to live apart from reason, according to one meaning, can be understood as a defect, as it is in those who live according to sense; and this is an evil in man. But in another way, it may mean to live above reason as when, by divine grace, a man is led to that which exceeds reason: and in this case, to live apart from reason is not an evil in man, but a good above that which is human. And such is the cognition of truths of faith, although faith itself is not in every way outside reason; for, it is the natural reason which holds that assent ought to be given to truths declared by God.

Article 2

Whether faith should be distinguished from religion

Obj. 1: It seems that faith ought not to be distinguished from religion, because, as Augustine says (Enchiridion): God is to be worshiped by faith, hope, and charity; (Augustine, Enchiridion, 3 (PL 40:232; CCL 46:49).) but worship of God is an act of religion, as is evident from the definition of Cicero, which says: religion is that which offers to a superior nature, which men call divine, worship and ceremony; (Cicero, On Invention, II c. 53 n. 161.) therefore faith pertains to religion.

Obj. 2: Augustine says in On True Religion that the true religion is that by which the one God is honored and known with a most unsullied piety or purity. (Augustine, On True Religion, 1.1 (PL 34:122; CCL 32:187; CSEL 77:3).) But to know God is a thing which belongs to faith; therefore, faith is contained under religion.

Obj. 3: To offer sacrifice to God is a function or act of religion, but this pertains to faith, as Augustine says in On the City of God, 4: true sacrifice is any work done in order that we may adhere to God in holy association; (Augustine, City of God, 10.6 (PL 41:283; CCL 47:278; CSEL 40.1:454).) but the first adherence of man to God is by faith; therefore faith pertains principally to religion.

Obj. 4: In John 4:24 it is said: God is a spirit, and they that adore him, must adore him in spirit and in truth. Now, God is adored more when one submits his intellect to him than when a bodily prostration is made; but through faith the intellect is submitted to God, since it subjects itself entirely in assenting to the truths revealed by God; therefore faith pertains especially to religion.

Obj. 5: Every virtue having God as its object is a theological virtue: but religion has God as its object, since it is nothing else than the offering of due reverence to God; therefore it is a theological virtue. But it appears to belong more to faith than to any of the others, since only those are said to be outside the Christian religion who are outside [i.e., without] faith; therefore religon seems to be the same as faith.

On the contrary is what Cicero says in Veteris Rhetoricae, 2 where he makes religion a part of justice, which is a moral virtue. (Cicero, On Invention, II c. 53 n. 161.) Therefore, since faith is a theological virtue, religion is of a genus other than that of faith.

Moreover, religion consists also in activity regarding the neighbor, as is evident in James 1:27: religion clean and undefiled before God and the Father is this: to visit the fatherless and widows in their tribulation; faith has no act except that which is referred to God; therefore religion is altogether distinct from faith.

Moreover, those are commonly called “religious” who are bound by special vows, but they are not the only ones called the faithful. Since, therefore, one of the faith and a religious are not the same thing, faith and religion are not the same.

I answer that it must be said that, as is evident from Augustine (On the City of God, 10), “theosebia,” which the worship of God is called, includes as pertaining to it in the same way, religion, piety and latria, since all have as their purpose the worship of God. (Augustine, City of God, 10.1 (PL 41:277–279; CCL 47:272–73; CSEL 40.1:445–47).)

Reverence paid to anything, however, seems to be nothing else than a due operation performed with regard to it; and consequently men are said to cherish in various ways their fields, their parents, their country, and other like things because different works are fitting to each. But God is not cherished in this same way: that any operation of ours would be of benefit or assistance to him, as in the case of the above-mentioned instances; but it implies only that we submit ourselves to him and show ourselves to be his subjects. Therefore this reverence which is absolutely divine is designated by the name of “theosebia.”

But religion implies a certain “binding back” according to which man obliges himself in some manner to this worship of God; wherefore Augustine says in his book, On True Religion: the word “religion” is thought to be derived from “religare” (“to bind back”), or from “recte eligere” (“to choose rightly”), as is said in On the City of God, 4. (Augustine, On True Religion, 55.113 (PL 34:172; CCL 32:259; CSEL 77:80); City of God, 10.3 (PL 41:280; CCL 47:275; CSEL 40.1:450).) For it is by proper choice that a person binds himself to do something that must be done. We must also reelect those things which by negligence we have lost, as he also says. Therefore it is that those who consecrate their whole lives and themselves to the service of God by certain vows are called religious.

But piety regards the mind of the worshiper, that it be not insincere or moved by desire of gain. Since also a certain divine veneration, as it were, is due to those above us, even the acts of kindness which are done for the unfortunate are in a way sacrifices to God, according to Hebrews 13:16: and do not forget to do good and to impart: for by such sacrifices God’s favor is obtained. Hence it is that the name of piety and of religion are transferred to works of mercy, and especially to benefits done to parents and country.

But latria implies a reverence that is of obligation, or worship in its essence; and this is so because we are, indeed, the subjects of him whom we honor, not after the manner in which one man is said to be the servant of another, because of some accidental debt to him, but because all that we are we owe to him as our Creator. Therefore latria is not any kind of service, but that by which man acknowledges his subjection to God.

Thus, therefore, religion consists in an operation by which man honors God by submitting to him; and this operation ought to be in harmony with him who is honored, and with the one offering homage. Now since he who is reverenced is a spirit, he cannot be approached by the body, but only by the mind; and so worship of him consists chiefly in acts of the mind by which the mind itself is ordained to God. These acts are principally those of the theological virtues; and in accordance with this, Augustine says that God is worshiped by faith, hope, and charity, to which are added also the acts of the gifts ordained toward God, such as those of wisdom and of fear. (Augustine, Enchiridion, 3 (PL 40:232; CCL 46:49).)

But because we who honor God are also possessed of bodies and receive our knowledge through bodily senses, there is the necessity that certain physical actions accompany the worship of God, not only that we may render service to God with our whole being, but also that by these bodily actions we may arouse in ourselves and in others acts of the mind ordained to God. Wherefore Augustine says in his book, On the Care of the Dead: those who pray make the members of their bodies conform to their acts of supplication when they genuflect, extend their hands, or prostrate themselves upon the ground, or perform any other visible action; and although it is their invisible will and the intention of the heart that is known to God, it is not unseemly that the human soul should so express itself, but rather by so doing man stirs himself to pray and to lament his sins the more humbly and fervently. (Augustine, On the Care of the Dead, 5.7 (PL 40:597; CSEL 41:632).)

Hence, all acts by which man subjects himself to God, whether they are acts of mind or of body, pertain to religion. But because those things that are rendered to the neighbor on account of God are rendered to God himself, it is evident that they also pertain to this same subjection in which religious worship consists; and so to one diligently considering the matter it is apparent that every good act pertains to religion. Hence Augustine says (On the Care of the Dead): true sacrifice is every work done that we may adhere to God in holy companionship; however, in a certain order. (Augustine, City of God, 10.6 (PL 41:283; CCL 47:278; CSEL 40.1:454).)

First and foremost, those acts of the mind ordained to God pertain to the worship which we are speaking of.

Second, there are acts of the body intended to arouse reverence of mind or to give expression to it, such as prostrations, sacrifices, and the like.

Third, there also pertain to divine worship all other acts ordained to the neighbor for the sake of God.

Nevertheless, as magnanimity is a certain special virtue, although it uses the acts of all virtues, since it bestows a grandeur in the exercise of them all and so regards its object under a certain special aspect; so also religion is a special virtue in the acts of all the virtues, considering a special aspect of its object, namely, that which is due to God; and thus it forms a part of justice. There are, moreover, special acts assigned to religion, which pertain to no other virtue, such as prostrations and the like, in which the worship of God consists secondarily.

From this it is evident that acts of faith pertain, indeed, materially to religion, as do the acts of other virtues, and the more so inasmuch as acts of faith are the first motions of the mind toward God; but formally faith is distinguished from religion, as regarding another aspect of its object. Faith agrees with religion also because faith is the cause and principle, of religion. For no one would elect to manifest reverence to God unless by faith he held that God was the Creator, ruler, and rewarder of human actions. Nevertheless religion is not a theological virtue: for it has as its matter all acts, as those of faith or ‘of any other virtue inasmuch as these are offered as due to God; but it has God as its end. For to worship God is to offer acts of this kind as due to God.

From what has been said, the response to all the objections is evident.

Article 3

Whether the Christian religion is aptly called catholic or universal

Obj. 1: It seems that the Christian religion ought not be called Catholic, because knowledge must be proportionate to the knowability of a thing. Now an indefinite thing is not known in any way at all: but faith is a knowledge of God who is neither universal nor particular, as Augustine says in his book, On the Trinity; (Augustine, On the Trinity, 7.6.11 (PL 42:943–44; CCL 50:262–64).) therefore this religion cannot be called universal.

Obj. 2: One can have only singular knowledge about singular things; but by faith we hold the truth of certain singular facts, as the Passion and Resurrection of Christ, and the like; therefore the Christian faith cannot be called universal.

Obj. 3: From what is common to many, it is not permissible to impose a name as proper to any one of them, since a name is given in order that a thing may be known as distinct: but every school or sect proposes certain things that must be universally held by all its followers, or certain doctrines that must be universally affirmed as true; therefore the Christian religion has no special right to be called Catholic.

Obj. 4: Idolatry extends to every corner of the earth; but the Christian religion has not yet been brought to all the regions of the world, since there are yet some barbarians who do not know the faith of Christ; therefore these idolatrous sects, rather than the Christian religion, deserve the name of Catholic.

Obj. 5: What does not include all should not be called universal; but the Christian religion is not accepted by many; therefore it is inaptly called universal or Catholic.

On the contrary is that which Augustine says in On True Religion: the Christian religion must be held by us, and the communication of that Church which is catholic and which is called Catholic, not only by its own members, but even by its enemies. (Augustine, On True Religion, 7.12 (PL 34:128; CCL 32:196; CSEL 77:12).)

Moreover, universal and common appear to be the same; but the Christian faith is called the common faith by the Apostle, as is apparent in Titus: to Titus, my beloved son according to the common faith (Titus 1:4); therefore it is rightly called Catholic.

Moreover, what is universally proposed to all should in a special way be called universal; but the Christian faith is universally proposed to all, as is evident in Matthew 28:19, teach all nations; therefore it is deservedly called Catholic or universal.

I answer that it must be said that faith, just as any other cognition, has a twofold matter: namely, that in which it exists (the believers themselves) and that about which it is concerned (the truths believed); and as regards both types of matter, the Christian religion can be called Catholic.

As regards the believers it is Catholic because the Apostle asserts that that is the true religion which was given testimony to by the law and the prophets (Rom 3:2). Since, however, in the times of the prophets various tribes offered worship to different gods, only one nation, the people of Israel, gave due honor to the true God, and so there did not exist that one universal religion which was foretold to them by the Holy Spirit, that worship of the true God which would be paid by all. Therefore Isaiah 45:24 says: for every knee shall be bowed to me, and every tongue shall swear.

And this prophecy has, indeed, been fulfilled by faith and the Christian religion. Therefore deservedly is that faith called Catholic since it has been accepted by men of every condition. And thus, those who have fallen away from this faith and this religion which has been so universally foretold and received, and who have become divided into various sects, are not called Catholics, but as it were, having been cut off from the communion of the faithful, they are called heretics.

As regards the truths proposed for belief in the Christian religion, there is also found truth that is catholic. Now, there were various arts and ways in ancient times according as there was vision, or belief in the vision of the human mind among men. For certain men placed the good of man in corporeal things alone, either in riches or in honors or in pleasures. Some others placed this good in the soul alone, as in moral or intellectual virtues. Certain others, as Augustine says in his book, On the City of God, thought that gods ought to be honored because of the corporeal blessings of this life; but others, on account of blessings to be realized after death. (Augustine, City of God, 6, Preface (PL 41:173; CCL 47:163; CSEL 40:266).) Porphyry also relates that it was believed among certain peoples of the earth that the imaginative part of the soul would be cleansed, but not the whole soul; and he said, as Augustine tells in On the City of God, 10, that there had not yet been found a single sect that possessed a universal way for liberty of spirit. (Augustine, City of God, 10.9, 10.32.1 (PL 41:312; CCL 47:309; CSEL 40:504).)

Now this way, as Augustine says in the same place, is the Christian religion. This religion teaches that God is to be honored not only on account of eternal, but also because of temporal benefits; that he rules man not only in spiritual ways but also in all that concerns him bodily, and that he promises beatitude for both soul and body. Hence his regulations are called universal, as pertaining to the whole life of man and as extending to all that in any way affects man.

For these two reasons, therefore, the name “universal” is given to the Christian religion, as Boethius in the text makes clear.

Reply Obj. 1: It may, therefore, be answered: although God is in himself neither universal nor particular, yet he is the universal cause and end of all things, and thus knowledge which is held concerning him is universal since it extends to all things.

Reply Obj. 2: It may be said: faith holds these particular facts as universal remedies for the healing and the liberation of the whole human race.

Reply Obj. 3: Answer may be made: other sects claim for themselves what is proper to the Christian faith, but they cannot vindicate this claim; therefore, the name of universality does not properly belong to them.

Reply Obj. 4: It may be said: idolatry was no one form of religion, but differed among various peoples, since they set up for themselves various gods to be worshiped. Nor again, were those forms of idolatry accepted by all nations, since they were rejected by those who honored the true God, and even by the philosophers of the Gentiles, who said that certain religious ceremonigeought to be observed since they were commanded by law, but not because they could be known to please the gods, as Seneca said, according to Augustine in On the City of God. (Augustine, City of God, 6.10.3 (PL 41:191; CCL 47:182; CSEL 40:297).)

Reply Obj. 5: It may be answered: the Christian religion is not called Catholic on account of individual nations who adhere to it, but on account of the body of individual men from all conditions of mankind who adhere to it.

Article 4

Whether it is a true article of faith, that the Father, Son, and Holy Spirit are one God

Obj. 1: It seems that it is not the confession of the Catholic faith that Father, Son, and Holy Spirit are one God: because, as Boethius himself says, upon inequality there follows plurality of gods. But the Catholic Scripture, which is the head of the Catholic religion, as Augustine says in On the True Religion, states that there is inequality between Father and Son, as is evident from what is said in the person of the Son: the Father is greater than I (John 14:28). (Augustine, On True Religion, 7.13 (PL 34:128; CCL 32:196; CSEL 77:12).) Therefore what is said is not the confession of the Catholic religion.

Obj. 2: In addition, 1 Corinthians 15:28 says: and when all things shall be subdued unto him, then the son also himself shall be subject unto him that put all things under him, that God may be all in all. And so the conclusion is like the former.

Obj. 3: Prayer is not made except by an inferior to a superior: but the Son prays for us: Christ Jesus . . . who also makes intercession for us (Rom 8:34). Likewise of the Holy Spirit it is said in the same place, the Spirit himself asks for us with unspeakable groanings (Rom 8:26). Therefore the Son and the Holy Spirit are inferior to the Father according to the confession of the Catholic faith, and so the conclusion is the same.

Obj. 4: Again, John gives the words of the Son addressing himself to the Father: that they may know you, the only true God, and Jesus Christ, whom you have sent (John 17:3). Therefore the Father alone is the true God, and not the Son and the Holy Spirit. Therefore they seem to be creatures, and so the same conclusion is reached.

Obj. 5: Also, the Apostle says about the Son, in 1 Timothy 6:15: who, namely Christ, in his times shall show, who is the blessed and only mighty, the King of kings, and Lord of lords. Who only has immortality and inhabits light inaccessible. Therefore all these titles belong only to the Father, and so the conclusion is as before.

Obj. 6: Also, in Mark 13:32 it is said: but of that day or hour no man knoweth, neither the angels in heaven, nor the Son, but the Father. Therefore the Father’s knowledge is greater than that of the Son. Consequently his essence also is greater, and thus the conclusion is the same.

Obj. 7: Also, in Matthew 20:23 he says: to sit on my right or left hand, is not mine to give to you, but to them for whom it is prepared by my Father. Therefore the power of the Son is not equal to that of the Father.

Obj. 8: Again, in Colossians 1:15 it is said of the Son that he is the firstborn of every creature. But this comparison would not be made unless of beings of one genus; therefore the Son is a creature.

Obj. 9: In Sirach 24:14 it is said in the person of divine Wisdom, from the beginning, and before the world, was I created. Thus the conclusion is the same.

Obj. 10: He who is revealed is less than he who reveals; but the Son is revealed by the Father, as is evident in John 12; therefore, the Son is less than the Father.

Obj. 11: The one sending is greater than the one sent. But the Father sends the Son, as is clear from Galatians 4:4, God sent his Son. And he also sends the Holy Spirit, according to John 14:26, the Paraclete, the Holy Spirit, whom the Father will send in my name. Therefore the Father is greater than the Son and the Holy Spirit. And thus the aforesaid doctrine does not seem to be in accordance with the Catholic faith.

On the contrary it is said in John 1:1, 3: in the beginning was the Word, and the Word was with God, and the Word was God. . . . All things were made by him. From this it is to be held that the Son is eternal, for otherwise he could not have been in the beginning: and that he is equal to the Father, for otherwise he would not be God: and that he is not a creature, for otherwise all things would not have been made by him.

Moreover, since the Son is truth, he could not lie concerning himself. But the Son said that he was equal to the Father, Whence is said in John 5:18: he also said God was his Father, making himself equal to God. Therefore he is equal to the Father.

Moreover, Philippians 2:6 says: he thought it not robbery to be equal with God. But it would have been robbery if he thought that was so which was not. Therefore he is equal to God.

Moreover, it is said in John 10:30, I and the Father are one.

Moreover, I am in the Father, and the Father in me (John 14:11). Therefore one is not greater than the other.

Moreover, in Romans 9:5: and of whom is Christ, according to the flesh, who is over all things, God blessed forever. Therefore no one is superior to him; and thus he is not less than the Father.

Moreover, 1 John 5:20, and we know that the Son of God is come: and he hath given us understanding that we may know the true God, and may be in his true Son. This is the true God and life eternal. Therefore he is not less than the Father. Again, it is shown that the Holy Spirit is the true God and equal to the Father by what is said in Philippians 3:3, according to the Greek text: we are the circumcision, who serve God the Spirit; for this is understood of the service of latria, as is evident in the Greek. And such honor is due to no creature: the Lord your God you shall adore, and him only you shall serve (Matt 4:10; cf. Deut 6:13). Therefore, the Holy Spirit is not a creature.

Moreover, the members of Christ cannot be the temple of anyone who is less than Christ: but our bodies, which are members of Christ, according to the Apostle, are temples of the Holy Spirit, as is said in 1 Corinthians 6:19. Therefore the Holy Spirit is not less than Christ, or less than the Father; and thus it is true, as the author says, that this is a doctrine of the Catholic religion.

I answer that it must be said that the position of the Arians, which establishes inequality among the divine persons, is not a confession of the Catholic religion, but rather an impiety of the Gentiles. This is evident thus. Among the Gentiles all immortal substances are called gods. Among these, moreover, they hold, or rather the Platonists hold, that there are three principal persons, as is made clear by Augustine in On the City of God, 10, (Augustine, City of God, 10.23, 10.29.1 (PL 41:300, 307; CCL 47:296, 304; CSEL 40.1:484, 496).) and by Macrobius on the Somnium Scipionis, (Macrobius, On the Dream of Scipio, I c.2 n.14–16 et c.6 n.20.) namely, the God, who is the Creator of all things, whom they call also the Father, since all things have their source in him; and, second, a certain inferior substance, whom they call the Paternal Mind or the Paternal Intellect, who contains the ideas of all things, and who is made by God the Father, they say; and third, after him they suppose a Soul-of-the-World, a spirit who is, as it were, the life of the whole world. And these three substances they name as their chief gods, and as the three principles by which souls are purified.

Origen, moreover, following the teachings of the Platonists, thought that after the same manner the doctrine of the true faith ought to be interpreted, because it is said in 1 John 5:7, there are three who give testimony in heaven. And so, as the Platonists supposed that there were three principal substances, Origen held that the Son was a creature and less than the Father, in that book which is entitled On First Principles, as is made clear by Jerome in a certain epistle regarding the errors of Origen. (Jerome, Letter 124: to Avitus, n.2 (PL 22:1060; CSEL 56:97).) And since Origen himself taught at Alexandria, Arius drank in his error from the things he wrote. On this account Epiphanius says that Origen was the father and font of Arius.

Therefore the position of the Christian and Catholic faith regarding the Trinity differs as much from the position of Arius as does the error of the Gentiles, which, in calling creatures gods, rendered to them the service of divine praise. The Apostle criticizes this in Romans 1:25 when he says, they worshiped and served the creature rather than the Creator.

Reply Obj. 1: It may be said: as Augustine states in On the Trinity, 2, passages found in the Scriptures in regard to the Father and the Son are threefold. (Augustine, On the Trinity, 2.1.3 (PL 42:846; CCL 50:82).)

First, some show a certain unity of substance and equality of persons, as, I and the Father are one (John 10:30).

Other passages show the Son to be less because of his having the form of a servant, according as he made himself less: he emptied himself, taking the form of a servant (Phil 2:7).

Certain things are also said that show him to be neither less nor the equal of the Father, but only that the Son is from the Father, as in John 5:26: as the Father has life in himself, so he hath given to the Son also to have life in himself.

The first authoritative passages are used by Catholics in making a defense of the truth. But those of the second and third kind are employed by heretics in confirmation of their error, though in a vain attempt.

For the things that are stated of Christ according to his human nature should not be referred to his divinity; otherwise it would follow that his death, which is recorded of him according to his humanity, would be according to his divinity.

Likewise, neither is it shown that the Son is less than the Father, although the Son is from the Father, because the Son has from the Father all that the Father possesses, as is held in John 16, and Matthew 11. Wherefore no inequality of divinity can be asserted because of the order of origin.

When, therefore, it is said, the Father is greater than I, this is said of the Son according to his human nature and not according to his divine nature, as Augustine maintains; (Augustine, On the Trinity, 1.7.14, 1.11.22 (PL 42:829, 836; CCL 50:45–46, 60).) or, as Hilary says, according to his divine nature in such a way that “greater” does not imply inequality (because the Son is not less than the Father, inasmuch as to him is given a name above all names); (Hilary of Poitiers, On the Trinity, 9.54 (PL 10:324 sqq.; CCL 62 A, 431 sqq.).) but it implies dignity of a principle inasmuch as it is from the Father that the Son possesses that by which he is the equal of the Father.

Reply Obj. 2: It may be said: all things the Father not only subjected to the Son, but the Son himself made them subject to himself, according to the saying of Philippians 3:21: according to the operation whereby also he is able to subdue all things unto himself; that is, according to the divinity which is equal in him to that of the Father. Wherefore, when it is said that Christ will be subject, this does not imply relation of the Son to the Father according to divinity, but rather the relation of the human nature of the Son to the divinity of the Father, which divinity is common to the whole Trinity. And when the divine nature shall be perfectly known, then it will be apparent that especially according to his human nature he is subject to the divine nature; but not with such a subjection as that which certain heretics claim who say that the very human nature which was assumed by the divine nature is transmuted into it, but rather that he is less than the Father by reason of his humanity. This is made especially clear by the fact that he will deliver his kingdom, that is, the faithful, to the Father, not claiming them for himself, but leading them to the vision of the Father, a vision in which his own divinity also will be seen.

Reply Obj. 3: It may be answered: according to Augustine (On the Trinity, 1), inasmuch as the Son prays he is less than the Father; but inasmuch as he obtains hearing with the Father, he is the equal of the Father. (Augustine, On the Trinity, 1.10.21 (PL 42:835; CCL 50:59).) That is, he prays according to his human nature, he hears according to divine. But the Holy Spirit is said to intercede for us inasmuch as he causes us to make intercession and renders our prayers efficacious.

Reply Obj. 4: It may be said: according to Augustine (On the Trinity, 6), (Augustine, On the Trinity, 6.9.10 (PL 42:930; CCL 50:239).) the statement that there is one only true God must not be interpreted to refer to the Father alone, but as including Father, Son, and Holy Spirit simultaneously; and they are said to be, the one true God because no being outside the Trinity is true God. Wherefore, it must be in this way that one understands: that they may know you, the only true God, and Jesus Christ whom you have sent (John 17:3). For there is one only true God, and no mention is here made of the Holy Spirit, because, since he is the nexus of the other two persons, he is understood by mention of the other two.

Reply Obj. 5: It may be answered: according to Augustine (On the Trinity, 1), (Augustine, On the Trinity, 1.6.10 (PL 42:826; CCL 50:39).) this saying is not to be understood of the person of the Father alone, but of the entire Trinity. For the whole Trinity is blessed and powerful, and the whole Trinity shows forth the Son. Even if he did say: he shall show, who is the Blessed and only Mighty, this would not indicate that the Son is separate from the Father, or that the Father is considered as being separated from the Son, because it is said in Sirach 24:8, in the person of the Son, who is the Wisdom of God, I alone have compassed the circuit of heaven. This is said, therefore, because in those things which pertain to the essence of God, Father and Son are altogether one, and hence what is said of one of them by diction which may be exclusive does not imply any mutual separation, but only their separation from creatures.

Reply Obj. 6: It may be said: the Son knows that day and hour, not only according to his divine nature, but even according to his human nature, since his soul knows all things. Hence he is said not to know that day, as Augustine explains in On the Trinity, 1, because he does not make it known to us; (Augustine, On the Trinity, 1.12.23 (PL 42:837; CCL 50:61).) wherefore he said to those questioning him: it is not for you to know the times (Acts 1:7). And in the same way the Apostle says in 1 Corinthians 2:2, I judged not myself to know anything among you, because he was unwilling to disclose lofty things to them since they lacked capacity to understand. Or this may be understood as regarding the Son, not in his character as head of the Church, but in the person of his members, since the Church, as Jerome says, is without knowledge of these truths. However, in saying that the Father alone knows them, it is evident that the Son also knows them, according to the aforesaid reason.

Reply Obj. 7: Answer may be made: as Augustine says in On the Trinity, 1, the verse: it is not mine to give to you, must be understood to mean that it is not in the power of human nature to give this, so that he may be known to grant it by reason of the fact that he is God and equal to the Father. (Augustine, On the Trinity, 1.12.25 (PL 42:838; CCL 50:64).)

Reply Obj. 8: It may be said: according to Augustine, On the Trinity, 1, many heretics, not understanding this point of apostolic doctrine, broke out into insult of the Son of God, saying and declaring that he was a creature, having little regard for the import of words. (Augustine, On the Trinity, 5.3 (PL 42:912; CCL 50:208).) For he is said, indeed, to be the first begotten, but not the first created, so that he might be believed to have been begotten, according to his divine nature, and to be first on account of his perpetuity. Moreover, although the Son belongs to no genus of creatures, yet, as Basil holds, he has something in common with creatures: (Basil the Great, Homily XV: On Faith, n. 2, trans. Rufinus of Aquileia, (PG 31:468 A, 1783 B).) namely, the fact that he received from the Father that which he has; but this possession is superior to that of creatures, since through his own nature he possesses what he receives from the Father. On this account there can be noted a certain order between the generation of the Son and the production of creatures.

Reply Obj. 9: It may be said: this saying and all sayings similar to it, which are read in regard to the wisdom of God, ought to be referred to the wisdom of creatures, such as the angels, or to Christ himself according to his human nature. Thus his wisdom is said to be from the beginning, or at the beginning of creation, as if from eternity it predestined that creation should belong to him.

Reply Obj. 10: Answer may be made: as Augustine says in On the Trinity, 2: (Augustine, On the Trinity, 2.4.6 (PL 42:848; CCL 50:87).) from the fact that the Father will glorify the Son, it does not follow that the Son is inferior to the Father; otherwise, he would be less than the Holy Spirit, because the Son says of the Holy Spirit in John 16:14: he shall glorify me. Now, this glorification refers not to the person of the Son, but to the fact that in the knowledge of men he will be glorified, since the Spirit will make him known; or it may be referred to the body which he had assumed and to the glory of the Resurrection.

Reply Obj. 11: It may be said: the Son and the Holy Spirit are said to be ‘sent’ by the Father, not that they now are where they had previously not been; but that, they are now there in a certain manner in which they had not previously been: that is to say, as regards a certain effect in creatures. Wherefore, when the Son and the Holy Spirit are said to have been sent by the Father, no inequality in the Trinity is revealed, but an order of origin, by which one Person is from another. Therefore the Father is not ‘sent’, because he is not from another in such a way that he has from another his efficacy in relation to any of his effects; and it is in this way that a divine Person is ‘sent’.

Question 4

Concerning those things that pertain to the cause of plurality

Inquiry is made of those things that pertain to the cause of plurality. And this inquiry involves four questions.

Whether otherness is the cause of plurality.
Whether variety of accidents produces diversity according to number.
Whether two bodies can be, or can be thought of as being, simultaneously in the same place.
Whether difference of location exerts some influence as to difference according to number.

Article 1

Whether otherness is the cause of plurality

Obj. 1: It seems that the cause of plurality cannot be otherness. For as is said in the Arithmetica of Boethius, all things whatever of the sum-total of beings that have been established in nature seem to ‘ have been formed by reason of numbers. (Boethius, On Arithmetic, I c. 2 (PL 63:1083 B).) For this was the principal exemplar in the mind of the builder of the universe: and this is in agreement with what is said in Wisdom 11:21, you have disposed all things in weight and in number and in measure. Therefore plurality or number is first among created things, and no cause of it is to be sought for.

Obj. 2: As said in the book De causis, the first of created things is being; (The Book of Causes, prop. 4 (ed. Pattin 54).) but being is divided at first by one and many; hence nothing can exist as prior to multitude except being and unity. Therefore it does not seem to be true that anything else should be its cause.

Obj. 3: Plurality either includes all genera according as it is distinguished from unity, which is convertible with being: or it is itself in the genus of quantity, according as it is distinguished from that unity which is the principle of number. But otherness is in the genus of relation, and relations are not causes of quantities, but rather the converse is true. Much less, then, is relation the cause of what is in every genus, because in that case it would be the cause of substance; therefore otherness can in no way be the cause of plurality.

Obj. 4: For contrary things there are contrary causes: but identity and otherness or diversity are opposites; therefore they have opposite causes. But unity is the cause of identity, as is evident in Metaphysics, 5; (Aristotle, Metaphysics, 5.11, 1018a4–9.) therefore plurality or multitude is the cause of diversity; and consequently otherness is not the cause of plurality.

Obj. 4: The principle of otherness is accidental difference; for differences of this kind, according to Porphyry, make a thing other. (Porphyry, Isagoge, trans. Boethius.) But accidental difference is not found in all things in which there is plurality; in fact, in some cases there is no difference of any kind. Certain things, such as simple forms, cannot be subjects of accidents; and there are other things that agree in no way, so that they cannot be called different, but diverse, as is evident by the words of the Philosopher in Metaphysics, 10. (Aristotle, Metaphysics, 10.3, 1053b23–27.) Therefore otherness is not the cause of all plurality.

On the contrary (5) is what Damascene says, that division is the cause of number; (John Damascene, On Faith, III c.5 (PG 94:1001), (Bt 185).) but division consists in diversity or otherness; therefore diversity, or otherness, is the principle of plurality.

Moreover (6), Isidore says that number is called, as it were, the master of numeration, that is, of division; (Isidorus: non invenimus) and so the conclusion is like the first.

Moreover (7), plurality is not constituted except by recession from unity; but there is no loss of unity except by division, since a thing is said to be one in that it is undivided, as is evident from Metaphysics, 10; (Aristotle, Metaphysics, 10.4, 1054a23.) therefore division constitutes plurality, and thus the conclusion is as before.

I answer that it must be said, as the Philosopher states in Metaphysics, 10, that a thing is said to be plural (many) from the fact that it is divisible or has been divided. (Aristotle, Metaphysics, 10.4, 1054a22.) Wherefore anything that is the cause of division ought to be regarded as a cause of plurality. Now, the cause of division cannot be considered the same in posterior and composite beings as in those that are first and simple.

For in posterior and composite things, the cause of division which is, as it were, the formal cause of division by reason of which division comes about, is diversity found in more simple and primary beings, as is made clear in the case of division according to quantity. For one part of a line is divided from another part by the fact that they have each a different place, which is, as it were, the formal difference of a thing of continuous quantity having position. It is also evident in the division of substances. For man is different from an ass because he has diverse constitutive differences: but the diversity by which posterior, composite beings are divided according as prior and simpler beings are, presupposes plurality of these same primary and more simple beings. For the reason why man and ass have diverse differences is that rationality and irrationality are not one and the same thing, but differ in many ways. Nor can it be said endlessly that the plurality of one thing is owing to another diversity in another prior and simpler cause, because thus we would go on to infinity.

Therefore it is necessary in some other way to assign a cause of plurality and division in prior and more simple beings. Now, there are some beings of this kind divided in themselves. Nevertheless it cannot be that being is divided from being, inasmuch as it is being: for nothing is divided from being except non-being. Likewise also from this-being, this-being is not divided, unless in this-being there is included negation of the same being. Wherefore in primary termini of thought negative propositions are immediately, as it were, negations, one of the other, in the intellect. For the first thing caused constitutes plurality with its cause, which does not reach to it [so as to be identical with it].

And according to this, certain philosophers hold that plurality is caused in a certain order from one and the selfsame thing; so that from one thing proceeds, at first, one being, which with its cause constitutes a plurality, and from this plurality, now two things can proceed, one according to the thing itself, and the other according to its conjunction to a cause.

But we are not forced to say this, since one thing might be able to imitate the first in some way in which the second would fail to agree with it; and this defect could be imitated in another; and so there can be found many effects of the first cause in any number of which there is both negation of the cause and negation of the effects in the same way, or according to distance separating one from the other.

So, therefore, it is evident that the first reason or, principle of plurality or division is from affirmation and negation, as the order of origin of such plurality is understood, because first there must be understanding of being and non-being, by which first divisions are constituted, and by this, there are the many. Hence, just as first being, inasmuch as it is undivided, is immediately recognized as one, so after division of being and non-being there is immediate recognition of the plurality of first simple beings.

The nature of diversity, moreover, follows upon plurality according as there remains in it the virtue of its cause, that is, the opposition of being and nonbeing. Therefore one of many diverse things is said to be related to another because it is not that other. And since a second cause does not produce its effect except by virtue of a first cause, therefore the plurality of first causes does not make division and plurality in secondary, composite beings unless there remains in that plurality the virtue of prime opposition, which is between being and non-being, by reason of which it has the nature of diversity; and thus the diversity of first causes produces the diversity of second.

According to this, it is true, as Boethius says, that otherness is the principle of plurality. (C. 1, n. 4.) indeed, otherness is to be found in things because there is diversity among them. However, although division precedes plurality of first causes, diversity does not; because division does not require the being of things divided among themselves, since division is by affirmation and negation, but diversity does require each to be a distinct being; wherefore it presupposes plurality. Hence it is in no way possible that the cause of the plurality of first beings should be diversity, unless diversity is employed as meaning division.

Boethius, therefore, is speaking of the plurality of composite beings, as is evident from the fact that he presents a proof involving those things that are diverse according to genus or species or number, and these kinds of diversity exist only in composite beings. (C. 1, n. 5.) For anything which is in a genus must be composed of genus and difference. Those, therefore, who declare the Father and Son to be unequal make declaration of composition, at least according to reason, inasmuch as they say the Father and Son agree in this, that they are God, but differ in the fact that they are unequal.

Reply Obj. 1: It may be said: in these words, number is shown to be prior to other created things, such as the elements and other such beings; but it is not prior to other notions, such as affirmation and negation or division and the like. Moreover, not every kind of number is prior to all created beings, but only number which is the cause of each thing, namely, God himself, who, according to Augustine, is number, giving species to every creature. (Augustine, On the Nature of Good, 3 (PL 42:553; CSEL 25.2:856).)

Reply Obj. 2: It may be answered: plurality, commonly speaking, im,mediately follows upon being; but this is not necessarily true of all plurality, and so it is not unfitting that the plurality of posterior beings should be caused by the diversity of those that are prior.

Reply Obj 3: It may be said: as one and many are not properly of one genus, so neither are the same and the diverse, but they are passions of being inasmuch as it is being, and hence there is no difficulty if the diversity of certain beings causes the plurality of others.

Reply Obj. 4: It may be said: some kind of plurality precedes all diversity, but diversity does not precede all plurality, yet some kind of diversity precedes certain plurality. Hence two things are equally true: namely, that, commonly speaking, multitude produces diversity, as the Philosopher says; (Aristotle, Metaphysics, 5.12, 1018a9–11.) and that diversity in composite things produces plurality, as Boethius here declares. (C.1, n. 5.)

Reply Obj. 5: It may be answered: Boethius is using “otherness” in place of “diversity,” which is constituted by certain differences, whether they are accidental or substantial. But those beings that are diverse yet not different are first beings, and Boethius is here not speaking of them.

Article 2

Whether variety of accidents produces diversity according to number

Obj. 1: It seems that variety of accidents cannot be the cause of plurality according to number. For the Philosopher says in Metaphysics, 5, that those things are numerically one in which the matter is one; (Aristotle, Metaphysics, 5.8, 1016b31–32.) therefore they are numerically plural in which the matter is plural; therefore variety of accidents does not produce diversity in number, but rather diversity of matter does so.

Obj. 2: As the Philosopher says in Metaphysics, 4, the cause of the substance and of the unity in things is the same; (Aristotle, Metaphysics, 10.1, 1052a33.) but accidents are not the cause either of the substance or of the unity in the individual; consequently they cannot be the cause of numerical plurality.

Obj. 3: All accidents, since accidents are indeed forms, are themselves communicable or common and universal: but nothing of this kind can be the cause of individuation in another, or a principle of individuation; therefore accidents cannot be principles of individuation. But certain things are diverse according to number inasmuch as they are divided in their own individuation; therefore accidents cannot be causes of diversity according to number.

Obj. 4: As those things that are in a genus or a species differ according to their substance, and not only according to an accident, so also those things that differ according to number must do likewise; but certain things are said to be diverse in genus or in species by reason of what is in the genus of substance, and not according to their accidents; therefore, in like manner, things are said to be numerically diverse according to what is in the genus of substance, and not according to accidents.

Obj. 5: If a cause is removed, so is its effect. Now it happens that every accident is removed from a subject either actually or by thought. If, therefore, an accident were the principle of plurality according to number and diversity, it would happen that the same things would sometimes be numerically one and sometimes diverse, either actually or by thought.

Obj. 6: What is posterior is never the cause of what is prior. But among all accidents, quantity holds first place, as Boethius says in Lib. praedicam. (Boethius, Commentary on the Categories, II (PL 64:201 D – 202 D).) Among quantities, however, number is prior since it is more simple and more abstract. Therefore an accident cannot be the principle of plurality according to number.

On the contrary is the statement made by Porphyry, that a collection of accidents which are not to be found in another produces the individual. (Porphyry, Isagoge.) But what is the principle of individuation is the principle of numerical plurality; therefore accidents are the principle of plurality according to number.

Moreover, in the individual, there is found nothing except matter, form, and accidents. Diversity of form, however, does not produce diversity according to number, but according to species, as is said in Metaphysics, 10. (Aristotle, Metaphysics, 10.11, 1058b1.) Now, diversity of matter produces diversity of genus. For the Philosopher says in Metaphysics, 10, that those things differ in genus in which there is not common matter, or generation of one into the other (mutual generation). (Aristotle, Metaphysics, 10.4, 1054b27–29.) Therefore diversity according to number cannot be produced except by diversity of accidents.

Moreover, what is found as common in many things that are specifically different is not the cause of diversity according to number, because the division of genus into species precedes the division of species into individuals; but matter is found to be common in things that are different in species because the same matter is possessed by contrary forms, otherwise beings having contrary forms would not be transmuted one into the other; therefore matter is not the principle of individuation according to number, and neither is form, as has been noted at the beginning. Hence it remains that accidents are the cause of this kind of diversity.

Moreover, in the genus of substance there is found only genus and difference; but the individuals of one species differ neither in genus, nor by reason of substantial differences; therefore they do not differ except because of accidental differences.

I answer that for the clarification of this question and of those other questions treated of in the text of Boethius, it is necessary to see what may be the cause of the threefold diversity spoken of in the text. Now, since in the individual composite in the genus of substance there are only three things (matter, form, and the composite), it must be that in each of these things the causes of their diversities are to be found. Accordingly it must be evident that diversity of genus is reduced to diversity of matter; but diversity according to species is reduced to diversity of form; whereas diversity according to number is owing partly to diversity of matter, and partly to accidental diversity.

Since, moreover, genus is the principle for knowableness of a thing, inasmuch as it is the first part of a definition, though matter in itself is unknowable, it is not possible that from matter in itself diversity of genus should be known, but only according to that mode by which it is knowable. Now, a thing is knowable in two ways.

In one way, by analogy, or by comparison, as is said in I Physics. (Aristotle, Physics, 1.13, 191a7–12.) Thus we say that this is matter or that matter is related to natural things as wood is to a couch.

In another way, a thing is known by the form because of which it has actual being. For everything is known inasmuch as it is in act, not according as it is in potency, as is said in Metaphysics, 9. (Aristotle, Metaphysics, 9.10, 1051a29–32.)

According to this aspect, diversity of genus derives from matter in two ways.

In one way, by analogous diversity in relation to form, and thus the first genera of things are distinguished according to matter. For what is in the genus of substance is referred to matter as to a part of itself; but what is in the genus of quantity has no matter as a part of itself, but is related to it as its measure, and quality is related as its disposition. And by means of these two genera (namely, quantity and quality), all other genera are diversely related to matter, which is a part of substance; hence substance has the nature of a subject and as such has a certain relation to accidents.

In another way, diversity of genus has its, origin in matter inasmuch as matter is perfected by form. And since matter is pure potency, just as God is pure act, to say that matter is perfected by act (which is form) is to say nothing else than that in some way it shares in a certain similitude to first act, imperfectly indeed, since what is composed of matter and form is midway between pure potency and pure act.

Moreover, matter does not receive similitude to first act in an altogether equal way, but in some things it is received imperfectly and in others more perfectly; thus, for example, some beings participate in a divine similitude inasmuch only as they subsist; others, in that they have knowledge; and still others, by possession of intellect. Therefore what is the similitude of first act in any existing matter is its form. But in some beings this form causes it only to exist, in others to exist and to live, and so, in one and the same being, form may be the cause of other perfections. For what is the more perfect similitude has everything that less perfect similitudes have by way of perfections, and more besides.

Something common, therefore, may be found in various similitudes, but possessed more imperfectly in some and more perfectly in cothers; just as matter may be subjected to both act and privation. And so matter, once taken together with this common element, is still material in regard to the aforementioned perfection and imperfection. From this material element it takes its genus, but its difference is from the perfection or imperfection of which we spoke above. For example, from this common material element (namely, having life), there is derived the genus “animated body”; but because of a superadded perfection there derives the difference “sensible,” while, on the other hand, from imperfection there is derived the difference “insensible.” Thus the diversity of such material things brings about diversity of genus, as that between animal and plant. On this account matter is said to be the principle of diversity according to genus, and in the same way, form is the principle of diversity according to species; because it is by reason of formal qualities which material things possess in addition to those which are the cause of their genus as material things, or by relation of form to matter, that the differences constituting species are derived.

However, it must be borne in mind that this “matter” whence genus is derived has in itself both form and matter. While the logician considers genus only according to its formal aspect, his definitions are said to be formal; but the natural philosopher considers genus from both aspects. Hence it sometimes happens that a thing shares in a logical genus in which it would not be classed according to the natural philosopher. Now, this happens when something by way of similitude to first act is found in a material thing, and again in one without matter, and again in a being altogether different in matter. Thus it is evident that a stone which is in matter in such a way as to be potential to being, attains to something of similitude to first act by being subsistent, and the sun also attains to the same similitude, though being in matter which is potential to place, but not any longer to being (having subsistent existence); and an angel likewise, although lacking any kind of matter.

Hence the logician, finding in all these beings that from which a genus derives, places them all in the genus of substance; but the natural philosopher and the metaphysician, who considers the principles of things, not finding these all to be in material agreement, says that they differ in genus; as is said in Metaphysics, 10: that corruptible and incorruptible differ generically and that those beings agree in genus whose matter is one and among which there is mutual generation. (Aristotle, Metaphysics, 10.12, 1058b26–29; 4, 1054b27–29.) Thus therefore it is evident in what way matter produces diversity in genus, and form produces diversity in species.

But among individuals of the same species diversity should be considered, according to that laid down by the Philosopher (Metaphysics, 7); namely, that just as parts of genus and species are matter and form, so the parts of the individual are this matter and this form. (Aristotle, Metaphysics, 7.10, 1035b27–31.) Therefore, just as diversity of matter causes diversity in genus, or diversity of form causes diversity in species, absolutely, so this form and this matter produce diversity in number.

But no form, as such, is of itself. I say, however, “no form, as such,” because of the rational soul, which in a manner is this something of itself, but not merely inasmuch as it is a form. Intellect, in truth, since it is a form capable of being received into anything—as its matter, or as its subject—can naturally be attributed to many; a thing which is contrary to the nature of that which is this something; hence it is made a form by the fact that it is received in matter. But since matter, considered in itself, is indistinct, it is not possible that it would individuate a form received into it, except as it is distinguishable. For no form is individuated by the fact that it is received into matter, except in so far as it is received into this matter, or it is this distinct form, determined to this, and at this time. Moreover, matter is not divisible except by quantity. Therefore the Philosopher says in Physics, 1, that if quantity were removed, a substance would remain indivisible: hence matter is made to be this matter and is signate inasmuch as it exists under dimensions. (Aristotle, Physics, 1.3, 185b16.) Dimensions, however, can be considered in two ways.

In one way according to their termination, and I say that they are terminated according to limited measure and figure; and so, as complete beings, dimensions are classed in the genus of quantity, and thus they cannot be the principle of individuation: because such termination of dimensions may frequently vary in regard to the same individual, and in such case it would follow that the individual would not remain numerically the same. In another way, dimensions may be considered without this certain determination, merely in the nature of dimension, although they never could exist without some kind of determination; just as the nature of color cannot exist without determination to white or black; and according to this aspect dimensions are classed in the genus of quantity as imperfect. And by these indeterminate dimensions matter is made to be this signate matter, and thus gives individuality to a form, and thus also by matter there is caused the numerical diversity of things in the same species. Therefore it is evident that matter, according as it is considered in itself, is not the principle of diversity, either according to species or according to number; but as it is the principle of generic diversity inasmuch as it is considered the subject of a common form, so it is the principle of numerical diversity inasmuch as it is considered as subject to indeterminate dimensions.

Therefore also, since these dimensions are in the genus of accidents, diversity according to number is reduced to diversity of matter, or to accidental diversity, according to the nature of the aforesaid dimensions. Other accidents, however, are not principles of individuation, but they are the principle of knowing the individual to be distinct. In this way individuation is also attributed to other accidents.

Reply Obj. 1: It may be said: when the Philosopher says that those things are numerically one in which the matter is one, this must be understood of signate matter which is the subject of dimensions; otherwise it would be necessary to say that all generable and corruptible things are numerically one, since their matter is one.

Reply Obj. 2: It may be answered: since dimensions are accidents, they cannot per se be the principle of the unity of an individual substance; but matter, inasmuch as it underlies such and such dimensions, is understood to be the principle of this unity and of this multitude.

Reply Obj. 3: It may be said: it is according to the nature of an individual thing that it be undivided in itself, and divided from other things by an ultimate division. No accident, however, has in itself the proper nature of division, unless it is quantity; therefore dimensions of themselves have a certain nature of individuation according to a determined place, inasmuch as place is a difference of quantity. Thus there is a twofold meaning of individuation: the one on the part of a subject, and this is the same for any accident; the other meaning, on the part of individuation itself, inasmuch as it has place, by reason of which, in abstracting from sensible matter, we may imagine this line and this circle. Hence it rightly pertains to matter to individuate all other forms, because it gives to this form, which of itself has the nature of individuation, that it also be terminated by those dimensions that are found in a subject now made complete; accordingly they are individuated by matter which is individuated by indeterminate dimensions conceived of as in matter.

Reply Obj. 4: It may be said: things that differ numerically in the genus of substance, differ not dinly because of accidents, but also by reason of form and matter; but if it is asked how this form differs from that, the only reason can be that it is in other signate matter. Nor can there be found another reason why this matter is divided from that except by reason of its quantity. Hence matter subject to dimension is undersiood to be the principle of this kind of diversity.

Reply Obj. 5: It may be said: this reasoning relates to completed accidents which follow upon the existence of a form in matter; but not to those indeterminate dimensions which may be conceived of before the reception of the form in matter. For without these, a thing cannot be understood to be individual, any more than it can be conceived of without form.

Reply Obj. 6: It may be answered: number, formally speaking, is prior to continuous quantity: but materially, continuous quantity is prior, since number is the result of the division of a continuum, as is said in Physics, 3. (Aristotle, Physics, 3.12, 207b13–14.) In this way, division of matter, according to dimensions, causes numerical diversity.

As to contrary reasons proposed, it is clear what must be conceded and what false conclusions have been deduced.

Article 3

Whether two bodies can be, or can be conceived of as being simultaneously in the same place

Obj. 1: It seems that two bodies can be conceived of as being in the same place. For any proposition seems to be intelligible in which there is included no opposition of the predicate to the subject, since such a proposition contains nothing repugnant to understanding. But this proposition, “Two bodies are in the same place,” is not a proposition repugnant to the intellect. Otherwise it could not happen miraculously, a thing evidently false regarding the body of our Lord, which came forth from the closed womb of the Virgin, and which entered into the midst of the disciples, the doors being shut. Now, even God cannot cause affirmation and negation to be simultaneously true, as Augustine says in answer to Faustus; (Augustine, Against Faustus the Manichee, 26.5 (PL 42:481; CSEL 25.1:732).) therefore one can understand, or at least conceive of in his mind, that two bodies could be in the same place at the same time.

Obj. 2: From glorified bodies there will be removed not the nature of corporeity, but only that of corpulentia (bodily mass). When this is removed, the possibility of being with other bodies in the same place is theirs by reason of the gift of subtlety, as is said by many. Therefore this condition does not follow the nature of corporeity, but that of corpulentia, of a certain mass. Therefore it is not impossible to conceive of two bodies being simultaneously in the same place.

Obj. 3: Augustine, in commenting upon the Book of Genesis says that, light holds the first place among corporeal things; (Augustine, On the Literal Interpretation of Genesis, 1.9.17 (PL 34:252–53; CSEL 28.1:13).) but light is simultaneously in the same place with air; therefore two bodies can be in the same place at the same time.

Obj. 4: Any species of fire is a body; but light is a species of fire, as the Philosopher says in Topics, 5. (Aristotle, Topics, 5.5, 134b28–30.) Therefore light is a body and so the conclusion is like the previous one.

Obj. 5: In glowing iron, the fire and the iron are simultaneous; but each is a body; therefore it is possible for two bodies to be in the same place at the same time.

Obj. 6: Elements in a compound are not corrupted; otherwise a compound would not follow the motion of a dominant element; but all four elements are bodies and are simultaneously in every part of the compound; therefore it is possible for two bodies to be simultaneously in the same place.

Obj. 7: The fact that two bodies are not simultaneously in one place does not occur by reason of the matter of the bodies, since to matter in itself there is no due place; nor does it occur because of the form, for the same reason; nor is it because of dimension, since dimensions do not fill up place, as is evident from the fact that certain philosophers are accustomed to say that the place where there are only dimensions is a vacuum. Therefore this characteristic of a body must arise only from certain posterior accidents, which are not altogether common and which can be separated from the body; and so it seems that two bodies could be simultaneously in the same place.

Obj. 8: According to the astrologers who follow Ptolemy, the six bodies of the planets move in epicycles, which are circles intersecting the spheres extrinsic to the planets. Therefore it must be that a body of a planet at some time would arrive at the place of section. But it cannot be said that at that place there is any vacuum, since nature does not suffer this; nor that the substance of the spheres is divisible, so that it might be thought of as giving way when the planetary body had reached it, as air gives way to a stone, for the heavens are most solid, being formed, as it were, of molten brass, as is said in Job 37:18. Therefore it must be that the body of the planet is simultaneously in the same place as the body of the sphere; and so Boethius falsely says that two bodies cannot occupy one and the same place. (C. 1, n. 5.)

On the contrary is the fact that if two bodies are in one and the same place, they are the same in nature and in every respect; but any body, however large, can be divided into small bodies of any quantity, according to any number; therefore, it would follow that in the very smallest place there would be contained the largest body, a thing which appears to be absurd.

Moreover, it is impossible for there to be many straight lines between two given points. But this would follow if two bodies could be in the same place. For then, given two points in two opposite parts of space, there will be between them two straight lines assigned corporeally to two places. Now, it cannot be said that between these two points there will be no lines at all, or that a line of one location would be greater than the other, or that there could be any one line apart from those corporeally located between the two points of given location, for in that case the two lines would not be in a subject. Therefore it is impossible for two bodies to be simultaneously in the same place.

Moreover, it has been demonstrated in geometry that two circles are tangent only at one point: but if we posit two bodies being simultaneously in the same place, it would follow that two circles could be totally tangent. Therefore it is impossible that two bodies should be in the same place at the same time.

Moreover, whatever things are equal to one and the same thing are equal to each other; but since local dimension must be one with a localized body (since no dimension can be supposed without a subject), if two bodies could be simultaneously in the same place, it would follow that the dimensions of each body would be equal to the dimensions of the place; therefore it would follow that the bodies would be the same, but this is impossible.

I answer that it must be said that in those things belonging to our world, all of which are judged to be corporeal, we see from sense experience that when one body arrives at any given place, any other body is expelled from that place; therefore it is experimentally evident that two such bodies cannot be in the same place.

There are, however, certain philosophers who declare that two bodies are not thus prohibited from simultaneous occupation of the same place on account of their corporeity, or on account of anything else which belongs to the nature of a body, as a body, for thus it would follow that it would be altogether impossible for two bodies to exist simultaneously [in the same place]. But they say that this prohibition is due only to their corpulentia. But whatever this corpulentia may mean—whether density or impurity or corruptibility which attends certain bodies, or even some special nature superadded to the general nature of corporeity—the prohibition can be on account of none of these things.

Now, there is to be found a double relation of a body to place. One is according as it has location in this or that determined place; and this relationship follows upon the specific nature of this or that body, just as heavy things, by the very nature of their gravity, hold a lower place, but light bodies, a higher place. But another relationship prevails according as a body is said, absolutely, to be in place: and this relationship characterizes a bodily thing by the very nature of its corporeity, not because of anything additional. For according as a particular body is in place, it is commensurate with that place; but this is because it has dimensions that are equal and similar to the dimensions of the place; moreover, dimensions belong to every body by reason of its very corporeity. For, that many bodies should or should not be in the same place, has no relation to a determined place, but regards place absolutely; therefore it must be that the cause of this impediment should be referred to the nature of corporeity, by reason of which every body, inasmuch as it is a body, is destined to be in place. And if the last sphere should not be in place, this is so only because nothing can be outside it, but not because it is lacking in the aforesaid aptitude to occupy place.

Hence there are others who concede that, absolutely, no two bodies can be in the same place at the same time, and they assign the reason for this to mathematical principles, which ought to be observed in all the natural sciences, as is said in On the Heavens and the Earth, 3. (Aristotle, On the Heavens, 3.3, 299a13–15; cf. Aquinas, Commentary on Aristotle's On the Heavens, bk. 3, lect. 3.) But this reason does not seem fitting, because it does not pertain to the objects of mathematics to be in place, except improperly and by similitude, as is said in On Generatione, 1. (Aristotle, On Generation and Corruption, 1.6, 323a1–3.) Hence, the reason for maintaining this impediment should not be derived from mathematical principles, but from the principles of natural things, to which place is properly due.

Furthermore, mathematical reasoning is sufficiently conclusive only in regard to its own matter. For, although mathematical truths are preserved in natural sciences, beings of the natural order add something over and above what is possessed by, mathematical beings: namely, sensible matter; and because of this addition it is possible to assign as an explanation of something in the natural order what would not be assigned in explanation of an object of mathematics. For in mathematics no reason for diversity of two given lines can be assigned except because of their situation; wherefore, if diversity of situation is removed, there remains no plurality of mathematical lines, and likewise no diversity of surfaces or of bodies. On this account mathematical bodies cannot be both many and simultaneous, and in like manner neither can lines or surfaces. But in regard to corporeal things in nature, it is possible to assign another and different reason for diversity: namely, that of sensible matter, even though diversity of situation were removed. Hence the reasoning which proves that two mathematical bodies cannot be simultaneously in the same place does not suffice for proving that two bodies in the natural order could not be simultaneous.

And therefore the explanation of Avicenna must be accepted, which he uses in his Sufficientia, in the treatise De loco. (Avicenna, Sufficientia, II c. 7 (ed. Venetiis 1508 f. 28 rb–29 rb).) In this explanation he assigns as reason of the aforesaid prohibition one which, by natural principles, is owing to the very nature of corporeity itself. For he says there can be no cause of this prohibition except that it pertains, first and per se, to a thing to be in place: but this means that it is destined by its nature to fill a place. Moreover, it does not pertain to a form to be in place, except accidentally; although certain forms are the principles by which a body is inclined to this or that place. Likewise neither does it pertain to matter, considered per se, to be in place, because, as so considered, it is understood apart from all genera, as is said in Metaphysics, 7. (Aristotle, Metaphysics, 7.2, 1029a20–21.)

Wherefore it must be that matter, according as it is subject to that by which it has primary relation to place, is the cause of this prohibition; but it is related to place inasmuch as it is subject to dimensions. Hence it is by nature of matter subject to dimensions that many bodies are prohibited from being in the same place. For, wherever the form of corporeity is found to be divided, there must be a plurality of bodies; but this division does not take place except by division of matter. Since division of matter is only by dimensions, because of which matter has situation, it is impossible that this matter should be distinct from that unless it is distinct according to situation. But this would not be the case if two bodies were posited as being in the same place; for then they would not be two bodies but one body, a thing which is impossible.

Since, therefore, matter subject to dimensions is found in all corporeal things, it must be by reason of the very nature of corporeity that any two bodies are prohibited from being in the same place at the same time.

Reply Obj. 1: It may be said: a proposition may be called not-intelligible in two ways.

In one way, it may be on the part of the one understanding, because of the deficiency of his intellect, as is the case in relation to this proposition: in the three divine Persons there is one essence. In a proposition of this kind, there can be, indeed, no contradiction.

In another way, non-intelligibility may be on the part of the proposition, and this again for two reasons.

In one way because it implies a contradiction, absolutely, as for example, “The rational is irrational.” And not even by a miracle can propositions of this sort be made true.

In another way, because they imply a contradiction in a certain manner, as this proposition: “The dead man rose to life by his own (proper) power.” For, by the fact that he is said to be “dead,” it is posited that he is destitute of every principle of life. Propositions of this kind can be made true by the miraculous operation of a superior power; and such is the case in regard to this proposition. For just as there can be found no natural cause of diversity for two bodies in the same place, so, by divine power, it is possible that two bodies be in the same place and that, although united in situation, their, distinction be conserved, as does miraculously happen.

Reply Obj. 2: It may be said: whatever may be this corpulentia, which is said to be removed from glorified bodies, nevertheless it is evident that corporeity will not be removed from them; therefore, neither will the cause which naturally prohibits any one of them from simultaneously occupying the same place with another; but only by a miracle is it possible that a glorified body be in the same place simultaneously with other bodies.

Reply Obj. 3: It may be answered: light is not a body, but a certain quality, as Damascene says, and Avicenna also. (John Damascene, On Faith, I c. 8 (PG 94:816 B), (Bt 34). Avicenna, Commentary on De anima, III c. 1 (ed. Van Riet p. 173).) But Augustine gives light the same name as fire, as is evident from the fact that he speaks of light as contradistinguished from air, water, and earth. (Augustine, On Free Will, 3.5.16 (PL 32:1279; CSEL 74:103).)

Reply Obj. 4: It may be answered: the three species of fire spoken of by the Philosopher are to be understood in such a way that by “light” is understood fire existing in its proper matter, and granted also, as some say, that fire in its own proper sphere emits no light. (Aristotle, Topics, 5.5, 134b28–30.) For it does not belong to the nature of light to be luminous, but by participation in it other things become so. The same is true of fire: for, although in its own sphere it emits no light, nevertheless, by participation in it, other things become refulgent. By flame, however, is to be understood fire in the air; and by carbo, fire in terrestrial matter. In aqueous matter, however, fire cannot continue in such a way as to have the nature of fire, because water has qualities which are altogether opposed to fire.

Reply Obj. 5: It must be said: in iron which has become ignited there are not two bodies, but one body having indeed the species of iron, but certain properties of fire.

Reply Obj. 6: It may be answered: although elements in a compound are supposed to remain according to their substantial forms, nevertheless it is not supposed that there are then many bodies in act, for otherwise no compound would be truly one; but while it is potentially many, it is one in act. Nevertheless the opinion of the Commentator, On the Heavens and the Earth, 3, seems the more probable. (Averroes, Commentary on On the Heavens, III comm. 67 (ed. Venetiis 1562 f. 227 r).) In rejecting the opinion of Avicenna, he says that the forms of elements neither remain in a compound nor are altogether corrupted, but that from them there comes to be one common or neuter form inasmuch as they comprise it, more or less.

But since to give rise to a substantial form “more or less” seems an improbability, it appears that this saying ought to be understood in this way: that the forms of the elements are receptive of more or less (or comprise the form of the compound, more or less), not secundum se, but according as they remain in elementary qualities, as it were in their proper instruments.

And thus it is said: forms remain virtually in the qualities of the elements certain instrumental properties, as it were. Forms secundum se, do not remain, but only according as they remain virtually in their qualities, out of which there is made one, median, or common quality.

Reply Obj. 7: It may be said: although dimensions of themselves cannot fill out a place, nevertheless a natural body, because of the fact that its matter is understood to be subject to dimensions, has the natural characteristic of filling a place.

Reply Obj. 8: It may be said: the opinion of Ptolemy regarding epicycles and eccentrics does not seem consonant with principles of natural philosophy which Aristotle holds; hence this opinion is not acceptable to the followers of Aristotle. If, however, it should be sustained, no necessity arises for supposing two bodies to be in the same place since, according to those who hold this opinion, the substances of heavenly bodies are distinguished as of three kinds: namely, the substance of the stars, which is luminous; the substance of the spheres, which is diaphanous and solid, but not divisible; and another kind of substance, which is between the spheres, and which is divisible and of resisting density, after the manner of the air, although this substance is incorruptible. And thus those who hold the theory of this third substance have no need to say that the substance of the spheres is divided or that two bodies occupy the same place simultaneously.

Article 4

Whether variety of location has any influence in effecting numerical difference

Obj. 1: It seems that variety of location effects nothing as regards diversity according to number. For the cause of diversity acicording to number is in those things which differ numerically; but place is outside things that are located; therefore diversity of place cannot be the cause of numerical diversity.

Obj. 2: A thing is not complete in being unless it is distinct from others; but place comes after complete being; therefore motion to a place is the motion of that which is perfect according to substance, as is said in Physics, 8. (Aristotle, Physics, 8.14, 260b33, 261a17–21.) Therefore it is not possible that any cause of the distinction of bodies occupying space should be derived from place.

Obj. 3: Numerical distinction is invariable as regards things that are distinct: but an invariable effect cannot proceed from a variable cause; therefore, since place varies in regard to that having location, it is not possible for diversity according to place to be the cause of numerical diversity.

Obj. 4: If a cause is removed, so also is its effect: but it sometimes happens by a miracle that distinction of place is removed in respect to two bodies, as has been previously said; yet distinction according to number is not removed; therefore distinction according to place is not the cause of numerical diversity.

Obj. 5: Diversity according to number is found not only in corporeal things, but even in incorporeal substances; but in these latter, diversity according to place cannot be the cause of numerical diversity, since incorporeal beings are not in a place, as Boethius himself says in his book, On Seven-day Cycles; (Boethius, Hebdomads, (ed. Peiper p. 169, 24 et infra p. 267 lin. 25).) therefore diversity according to place cannot be taken as the cause of diversity according to number, that is, as its cause by very reason of its nature, as he himself seems to say.

On the contrary is the fact that things differing according to number differ by reason of their accidents: but the diversity of no other accident is so inseparably related to diversity in number as is diversity of location; therefore diversity in place seems especially to influence diversity in number.

Obj. 2: Again, diversity of location according to the species of things is concomitant with the diversity of bodies according to their species, as is evident in the case of heavy and light bodies. Therefore also diversity of places according to number is indivisibly concomitant with diversity of bodies according to number, and so the conclusion is the same as before.

Obj. 3: Again, as time is the measure of motion, so place is the measure of a body: but motion is divided numerically according to time, as is said in Physics, 5; (Aristotle, Physics, 6.6, 235a10–13.) therefore also what is corporeal is divided numerically according to place.

I answer that it must be said that, as is evident from previous statements, diversity according to number is caused by division of matter existing under dimensions. Now, matter itself, according as it exists under dimensions, prohibits two bodies from being in the same place, inasmuch as in each of the two bodies there must be matter distinct in its situation. And thus it is evident that diversity according to number is caused by the same thing as diversity of location in diverse bodies. Hence diversity of location, considered in itself, is a sign of the diversity which exists according to number—just as is also true of other accidents, except the first indeterminate dimensions which have been previously discussed. But if diversity of place is considered according to its own cause, then it is clear that diversity of place is the cause of diversity according to number. Therefore Boethius says it is variety of accidents that produces diversity according to number. But if all other accidents are removed, numerical diversity still remains verifiable by reason of the diversity of things in place; since, indeed, no other of those accidents which appear as extrinsic to a complete being is so closely related to the cause of diversity according to number as is diversity of location.

Reply Obj. 1–3: To the first, second, and third objections it may be said: these reasons show conclusively that diversity of place is not the cause of diversity of individuals, secundum se., but this does not refute the fact that the cause of diversity of locations is the cause of diversity according to number.

Reply Obj. 4: It may be answered: all effects of second causes depend more on God than on secondary causes, since either with these second causes, or without them, he is able to produce miraculously whatever effects he wills.

Reply Obj. 5: It may be said: in corporeal substances diversity according to species follows diversity according to number, except in the case of the rational soul, which follows division of matter disposed for it. Here, however, Boethius is speaking of diversity according to number where the species is the same.

Reply Obj. 1: In contradiction to the first objection, it may be said: variety of accidents, because of indeterminate dimensions, does not produce diversity in number after the manner of a cause, but this variety is said to produce, a sign indicating numerical diversity; and diversity of place does this in a special way, inasmuch as it is the sign, most closely related to numerical diversity.

Reply Obj. 2: To the second, it may be answered: diversity of locations according to species is a sign of diversity of bodies according to their species, but not a cause of specific diversity.

Reply Obj. 3: To the third, it may be said: although division of time is caused by division of motion, diversity, even diversity of time is not the cause of diversity of motion, but a sign of it; and the same is true of location in its relation to a body.

Chapter 4 of 6