D. 13 - Work of distinction of the first day

Division of the text

Having spoken of the work of creation, here he proceeds to the work of distinction. And this is divided into three parts.

In the first, he examines the work of the first day.

In the second, he examines the work of the second day, at God said, ‘let there be a firmament.’ (Sent. II, 14.1(71).1, quoting Genesis 1:6–7.)

In the third, he examines the work of the third day, at next: God said, ‘let the waters be gathered in one place.’ (Sent. II, 14.7(77), quoting Genesis 1:9.)

The first is divided into two parts.

In the first, he examines the first work of distinction through the production of light.

In the second, he explains certain doubts that can arise in things said against this work and concerning the following works, at moreover, one must inquire how that statement should be taken: ‘God said.’ (Sent. II, 13.6(69), referring to Genesis 1:3.)

Concerning the first, he does three things.

First, he examines the production of light.

Second, he examines its conditions, at if it is asked what that light was. (Sent. II, 13.2(65).1.)

Third, he examines the light’s effect and so forth, at here it is to be noted that day is taken in different ways in Scripture. (Sent. II, 13.4(67).1.)

The second is divided into two parts.

In the first, he shows the condition of the light with regard to its nature or genus.

In the second, he shows it with regard to its place, at ‘but if it is asked where that light was made . . . it can be said that it was made in those parts over which now shines the daylight of the sun.’ (Sent. II, 13.3(66).1, quoting Bede, Libri quatuor in principium Genesis, bk. 1, at 1:3 (CCSL 118A; PL 91:17).)

In the third part, he considers the light’s effect, which is the day. This is divided into three parts.

In the first, he distinguishes various understandings of “day.”

In the second, he distinguishes the day with regard to the order of its parts, at this is the natural order of distinction of days. (Sent. II, 13.5(68).5.)

In the third, he considers it with regard to efficient cause, at but it is usual to ask, ‘why was the sun made?’ (Sent. II, 13.5(68).3.)

Moreover, one must inquire how that statement should be taken: ‘God said.’ (Sent. II, 13.6(69).) Here he explains how we should understand the fact that it says, God said.

First, he gives the explanation.

Second, he removes a consequent doubt, at here it is usual to ask how this statement should be taken: the Father works in the Son. (Sent. II, 13.7(70).1.)

Concerning this he does three things.

First, he raises the question.

Second, he lays out the error of some, at some heretics held that the Father, as author and artificer, used the Son and the Holy Spirit almost like an instrument in the making of things. (Sent. II, 13.7(70).2.)

Third, he determines the truth, at we are not to understand Scripture’s frequent recalling of the Father working in the Son, or through the Son, as if the Son could not do anything without the Father stretching out his right hand to him. (Sent. II, 13.7(70).3.)

There he offers two solutions.

The second of these begins at it may also be taken in another way. (Sent. II, 13.7(70).5.)

Concerning the first, he does two things.

First, he offers a reply.

Second, he rules out the opposition of heretics, at but the heretic says. (Sent. II, 13.7(70).4.)

Question 1

The work of the first day

Here five questions are asked:

first, concerning the work of distinction as different from other works;

second, whether light is found in spiritual things properly;

third, whether bodily light is a substance or an accident;

fourth, concerning the production of light;

fifth, how the Father is said to work through the Son.

Article 1

Whether the work of distinction was necessary after the work of creation

To the first we proceed as follows. (Parallel texts: ST I.47.1; SCG II.39–45; III.97; On the Power of God, q. 3, a. 1, ad 9; a. 16; Compendium theologiae, cc. 71–72, 102; Commentary on Aristotle’s Metaphysics, bk. 12, lect. 2; Commentary on the Book of Causes, lect. 24.) It seems that after the work of creation, the work of distinction was not necessary.

Obj. 1: For distinction belongs only to what was first confused and combined. Therefore, since the distinction of things took place after creation, things must first have been created as mixed. In this case, the opinion of Anaxagoras and Anaximander (Aristotle, Metaphysics 12.2, 1069b20–25.) will return, that things are made through extraction from a single confused and mixed thing.

Obj. 2: Furthermore, creation is terminated in being. For a being, as is said in the Book of Causes, (Proclus, Book of Causes, prop. 8.) exists through creation. But matter is distinct with respect to being, even though it is one with respect to essence. Therefore, it seems that after creation there is no need of distinction.

Obj. 3: Furthermore, distinction belongs to those things that can be combined and confused with respect to place. But combination and confusion only happen to things that share in matter. So if there is no matter common to higher and lower bodies, it seems that no distinction can be made of the higher from the lower.

Obj. 4: Furthermore, any given body is distinct from other bodies. Therefore, since the text describes the distinction of the crystalline heaven and the starry heaven, it seems unfitting to leave the distinction of the empyrean heaven unmentioned.

Obj. 5: Furthermore, it was said above in the text (Sent. II, 12.1(58).2; cf. Distinction 12.) that God distinguished created things by species over the six days. Therefore, it seems that the whole work of the six days pertains to distinction. Thus, adornment seems not to differ from the work of distinction.

I answer that in the works of the six days nature was established in such a way that the principles of nature then created would subsist in it, and that from them others would be able to be propagated through mutual action and passion. Thus, being had to be conferred on them at that time as well as active and passive powers, which Augustine calls “seedlike principles,” from which consequent effects would be produced. (Augustine, On the Literal Interpretation of Genesis, bk. 5, ch. 4 (CSEL 28.1:143; PL 34:324).) So the work of creation, through which the substance of the elements of the world was brought into being, regards the being of these principles. But of the active and passive powers, some are movers with regard to determinate species, such as the power that is in the seed of a lion and a horse. However, others are common and are movers with regard to every species, such as hot, cold, and things of this sort. Therefore, through the work of distinction, common active and passive powers that move with regard to every species were bestowed upon created things. But through the work of adornment, powers moving with regard to determinate species were conferred on things.

But there can only be three kinds of distinction. For since the motion of alteration according to which generation and corruption occur is traced back to a single first thing that alters and is not altered, namely, heaven, there must be three things in the essential principles of the world. The first is what alters and is not altered, such as heaven. The second is what alters and is altered, such as the middle elements, that is, fire, water, and air. The third is the last and has the least power of altering, namely, earth. Therefore, in the first place, the first had to be distinguished from the last, and this occurred through the production of light, which is formally in the heavens and which is participated in by the middle elements to greater or lesser degree, while the last element, namely earth, lacks light or has a minimal amount of it. Second, the first had to be distinguished from the middle, and this occurred on the second day, when by the creation of the firmament the lower waters were divided from the higher. Third, there is the division of the middle from the last, and this occurred on the third day when the waters were gathered together into one place and dry land appeared.

Reply Obj. 1: The distinction of the parts of the world is not to be understood as a material extraction from a mixed body, but rather formally, as the conferral of different powers on different things.

Reply Obj. 2: Through the work of creation the principles of the world were distinguished with regard to primary being, which is through substantial forms. But the work of distinction had to come in for them to be distinguished with regard to action and passion, according to the different powers conferred on things.

Reply Obj. 3: There is a certain diversity among these distinctions. For because higher bodies are not of the same matter as lower bodies, and, consequently, cannot be confused with them as regards place, the first distinction, that of first from last, and the second, that of first from middle, only regard the conferral of different powers for action and passion. But the third—that of the middle element from the last, which elements can be mixed together and confused as regards place—regards both, inasmuch as qualities that are the principles of alteration were conferred on the elements, such as heat, cold, and things of this sort, as well as the things that are the principles of local motion, such as heaviness and levity. Thus, it was on the third day that mention was made of place when it is said, let the waters be gathered together into one place, not the preceding days.

Reply Obj. 4: As was said above, (Above: d. 2, q. 2, a. 3, resp.) the empyrean heaven does not have influence over lower bodies. Thus, it did not need to be mentioned among the works of distinction, through which active powers were given to things. Rather, the empyrean heaven was ordered toward the glory of the blessed, and so it possessed its whole completion from the beginning of its creation.

Reply Obj. 5: The work of distinction has been taken above in a general way as indicating any sort of separation with regard to power. In this way, it includes adornment. But in another way, it differs from adornment, as has been said. (Resp.) This difference can be drawn from Scripture’s own way of speaking, which insinuates a kind of division in the works of the three days.

Article 2

Whether light is found properly in spiritual things

To the second we proceed as follows. (Parallel texts: ST I.67.1; Commentary on John, ch. 1, lect. 3.) It seems that light is found properly in spiritual things.

Obj. 1: This is first from what John 1:9 says: the true light that enlightens every man was coming into the world. This refers to God, who is maximally spiritual. Therefore, it seems that light is properly found in spiritual substances.

Obj. 2: Furthermore, Augustine says: Christ is not called light in the same manner as he is called a rock; rather, the former is said properly, the latter figuratively. (Augustine, On the Literal Interpretation of Genesis, bk. 4, ch. 28 (CSEL 28.1:127; PL 34:315).) But Christ would not be properly called “light” unless light were properly found in spiritual things. Therefore, and so on.

Obj. 3: Furthermore, among other creatures, the spiritual substance is more noble, as being closer to God. But it is not probable that the divine Scripture has passed over the noblest creature’s creation in silence. So, since it does not mention the creation of angels, it seems that the creation of the angelic nature should be understood in a literal sense and properly by the production of light.

Obj. 4: Furthermore, active being befits light most of all. Hence diffusive being is attributed to light. But action more truly befits spiritual things than bodily ones. Therefore, so too does light.

Obj. 5: Furthermore, the proper act of light is to manifest. But manifestation is found more properly in spiritual things, where there is nobler knowledge. Therefore, it seems that light, too, is more truly found in them.

On the contrary, there is what Ambrose says, (Ambrose, On the Faith, to Gratian, bk. 2, prologue (CSEL 78; PL 16:583): sunt evidentia indicia quae proprietatem deitatis ostendant; sunt quae similitudinem Patris et Filii; sunt etiam quae perspicuam divinae majestatis exprimant unitatem. Proprietas itaque sunt Deus, Filius, Verbum; similitudinis, splendor, character, etc.) who includes among things said of God by transposition the brightness that occurs due to the multiplication of light. (See the note in the body of the following article on the words lux and lumen.)

Furthermore, Dionysius says (Pseudo-Dionysius, On the Divine Names, ch. 4 (PG 3:698).) that God is called “light” because likeness to him with regard to causality is especially reflected in the sun’s ray. But every name that is said of God by way of likeness drawn from a bodily creature belongs to him metaphorically. Therefore, and so on.

I answer that in this matter there seems to be some diversity among the saints. For Augustine seems to want to say that light is more truly found in spiritual things than in bodily ones. But Ambrose and Dionysius seem to indicate that in spiritual things it is found only metaphorically. And, in fact, this seems more true. For essentially sensible things befit spiritual things only metaphorically because, although something common can be found analogously in spiritual and bodily things, yet this does not determine something essentially sensible, as is clear if we take the examples of being and heat. For being is not sensible in and of itself, and it is common to both; but heat, which is essentially sensible, is not found in spiritual things properly. Hence since light is the quality of the essentially visible and a determinate species in sensible things, it cannot be said to be in spiritual things except either equivocally or metaphorically.

Still, it should be known that bodily things are transferred to spiritual things by way of a kind of likeness, which is a likeness of proportionality. It is necessary to reduce this likeness to a commonality of univocation or of analogy. And so it is in the case in question. For in spiritual things that is called “light” which is related to intellectual manifestation, just as bodily light is related to sensible manifestation. But manifestation is more truly in spiritual things. In this regard, Augustine’s statement—that light is more truly in spiritual things than in bodily things—is true, not with respect to the proper account of light, but rather with respect to the account of manifestation, as it says in the canonical epistle of John: all that is made manifest is light. (Rather: Ephesians 5:13: omnia autem, quae arguuntur, a lumine manifestantur: omne enim, quod manifestatur, lumen est.) This is the way in which everything manifest is called “clear” and everything hidden is called “obscure.”

Reply Obj. 1: God is called “the true light” with regard to his truth, from which a likeness is taken, not with regard to the true nature of light. He is called “the true vine” in the same way (John 15:1).

Reply Obj. 2: Augustine takes greater account of the account of manifestation than he does of the name “light.” Or we may say that the things he says in that passage, he says not as an assertion, but as an inquiry, as he himself bears witness in Chapter 28. (Augustine, On the Literal Interpretation of Genesis, bk. 4, ch. 28 (CSEL 28.1:127; PL 34:315).)

Reply Obj. 3: According to Dionysius, the divine Scripture proposes spiritual things to us under the likeness of bodily things. (See Pseudo-Dionysius, Celestial Hierarchy, ch. 2, para. 3 (PG 3:139–42).) Thus, it was not fitting for it to describe the creation of the angels expressly. Rather, it would have us understand their creation from the production of bodily light.

Reply Obj. 4: It is not just any action that pertains to the proper nature of light, but rather such as is found in bodily things. Likewise, it is not just any manifestation, but rather that which regards the sense of sight.

Reply Obj. 5: Hence the reply to the fifth objection is clear.

Article 3

Whether light is an accident

To the third we proceed as follows. (Parallel texts: ST I.67.2; Commentary on Aristotle’s On the Soul, bk. 2, lect. 14.) It seems that light is not an accident.

Obj. 1: First, by the authority of Augustine, who says (Augustine, On the Free Choice of the Will, bk. 3, ch. 5 (CCSL 29; PL 32:1276).) that light holds the first place among bodily things, and he says many such things in his books. But no body is an accident. Therefore, and so on.

Obj. 2: Furthermore, whatever things are joined together and separated from one another while remaining the same numerically are not accidents, since an accident does not pass from subject to subject, nor can two distinct accidents of the same species be in the same subject. But the lights of two luminaries are joined together and separated from one another, as Dionysius says. (Pseudo-Dionysius, On the Divine Names, ch. 2, n. 1 (PG 3:640).) Therefore, light is not an accident.

Obj. 3: Furthermore, whatever is predicated of a genus is predicated also of the species. But according to the Philosopher, (Aristotle, Topics 5.5, 134b28; cf. 2.3, 110a24–111a7.) light is a species of fire. Therefore, since fire is a body and a substance, it seems that light is as well.

Obj. 4: Furthermore, only bodies are moved, as is proved in the Physics 7. (See Aristotle, Physics 6.10, 240b10.) But the rays descending from the sun to us are moved. Therefore, they are a body.

Obj. 5: Furthermore, nothing bounces off a body except a body, since a body is no obstacle to an accident. But the rays of the sun bounce off a solid body. Therefore, and so on.

Obj. 6: Furthermore, it is a property of bodies that heat results from their being rubbed together and compressed. But from the intersection and multiplication of the sun’s rays, heat results. Therefore, and so on.

Obj. 7: Again, nothing acts beyond its species, since the effect is not higher than the agent. But through the light of the sun, substantial forms are produced in lower bodies, as is clear from Dionysius (Pseudo-Dionysius, On the Divine Names, ch. 4, n. 1 (PG 3:699).) where he says that sunlight confers the power of generation on visible bodies and moves them even to life. Therefore, since a substantial form is beyond the nature of an accident in perfection and dignity, it seems that light cannot be an accident.

Obj. 8: Furthermore, if it is an accident, it must be traced back to some genus of accident. And it cannot be traced back to genus other than that of quality. Within the genus of quality it seems that it can only belong to the third species. Therefore, since it is not in the third species of quality, it seems that it is not an accident. That it is not in the third species of quality is proved in the following way. In that species we find passion or passible quality. (“Passible” in this context means “changeable,” with the implication that it can be observed by the senses. Compare the note above in d. 11, q. 1, a. 5, ad 2. See also Aristotle, Categories 8, 9a29–10a9.) But to any given passible quality there is something contrary. Therefore, since nothing is opposed to light as its contrary, but only by way of privation, namely, darkness, it seems that light is not in the third species of quality.

Obj. 9: Furthermore, every passible quality is introduced into matter successively. For motion with respect to a passible quality is an alteration, which is successive. But illumination happens at once. Therefore, light is not a quality of this sort.

Obj. 10: Furthermore, passible qualities impressed on a subject by some agent remain for some time, even when the agent is removed, as is clear in the case of water that has been heated. But luminosity produced in the air immediately ceases to exist at the absence of the sun that illuminates. Therefore, and so on.

On the contrary, Damascene says that light is a quality of fire. (John Damascene, On the Orthodox Faith, bk. 1, ch. 8 (PG 94:819).) But quality is an accident. Therefore, so is light.

Again, Avicenna says (Avicenna, Liber de anima, pt. 3, ch. 1.) that luminosity is the quality of a luminous body precisely as such, and that lucidity is the quality that a transparent body borrows from the luminous body. Therefore, it seems that lucidity as well as luminosity is an accident.

I answer that these four things differ: (Latin has two words for light: lux and lumen; they are typically interchangeable, even in Aquinas’s own usage (as can be seen in this and the previous article), although he tends to use lux. Thus, we usually will translate both words as “light.” However, following the Latin text of Avicenna and others (see the sed contra), Aquinas will sometimes suggest that lux more properly names the quality that belongs to a light-source (such as the sun or a flame), whereas lumen more properly names the same quality effected by the light-source but present in a transparent medium (for example, the air or water). As a general rule, the reader should be aware that Aquinas’s understanding of light is subtle, and he may have this distinction in mind when he uses the one word rather than the other. In instances where Aquinas is clearly distinguishing the terms, this translation gives neither as “light,” opting instead for “luminosity” for lux and “lucidity” for lumen. This of course is etymologically an inversion, but it better approximates English usage, since we call a lamp “luminous,” but not “lucid,” and we call clear water “lucid,” but not “luminous.”) luminosity, lucidity, a ray, and shine. For “luminosity” refers to what is in a body that is actually luminous and from which others are illuminated, as in the case of the sun. “Lucidity,” however, refers to what is received in a transparent body so illuminated. And “ray” refers to illumination in a direct line to a luminous body, and, thus, wherever there is a ray there is lucidity; but this is not convertible, for there can be lucidity in a house due to the reflection of the sun’s rays, though not due to being directly in their path, on account of some intervening body. Finally, “shine” is due to the reflection of a ray on some body that is clean and smooth, such as water, silver, or something of this sort, from which rays are also sent forth by reflection.

Therefore, having seen these things, one should know that there are many opinions concerning the nature of luminosity and lucidity. Some said that luminosity is a body, the very substance of the sun, from which flow certain other bodies, and that these bodies are called “lucidity” or a “ray.”

But this position has been disproved by philosophers in many ways.

The first way is because it would follow that illumination is a local motion of bodies flowing from the sun. Since local motion cannot be instantaneous, it would follow that illumination occurs successively, a succession that could not be hidden to the senses over such a great distance, that is, from east to west as well as from the sun to us.

The second way is because it would follow that two bodies would be in the same place at the same time, since the whole space that is illuminated is filled with air, though some of the philosophers do not regard this as unfitting, completely ignoring the senses. Others, however, say that lucidity is received in channels in the air. But this is ridiculous. For then there would be empty channels in darkened air, and air would never be illuminated entirely, and many such problems would follow.

The third way is because those bodies either are extracted from the substance of the sun, and in this case it would have to grow smaller every day and at some point be used up—unless, perhaps, it is said that it is fed on vapors rising from the water and earth such that the bodies depleted in this way are restored, which is altogether outlandish. Or those bodies would have to be newly made continuously. Either this would be from preexisting matter, in which case they would come to be through the corruption of other things; and since there is illumination in heaven, it would follow that some bodies there are corrupted in order for the others to be generated, and many other absurd things. Or they would be made by the creation of new matter, which is contrary to the principles of nature, nor could there then be any illumination except by a miracle of God. It would follow, too, since created bodies are not reduced to nothing, that the quantity of the world would always be increasing by the new bodies created every day, and many such absurd things. Moreover, Avicenna lays out many arguments against this in On the Soul. (Avicenna, Liber de anima, pt. 3, ch. 3.)

Hence this position must be abandoned as absurd and bizarre. For it cannot be maintained except by the discovery of other principles of natural philosophy.

But others say that the lucidity received in a transparent body is an accident, since it arrives after a thing’s being is completed and withdraws while the things remain. However, in a luminous body luminosity is substance, either the luminous body itself, according to some, or its substantial form, according to others. Again, this cannot stand. For illumination is a univocal action, since what is luminous illuminates. Hence if lucidity in this air is an accident, then the beginning of the illumination in a luminous body must be an accident, just as the Commentator also proves that heat is not the substantial form of fire because it is an accident in heated bodies. Moreover, no substance is sensible through itself, since the “what-it-is” is the object of the intellect. Hence light, which is sensible through itself, must not be a substantial form. And if it be said that what is seen is not light but rather a kind of brightness, then we must say that what we are calling “light” is that which is seen through itself. And if the substantial form of the sun is called “light,” this will only be equivocally, since an accident and a substance cannot be spoken of univocally in any respect. In this way, nothing prevents even a stone from being called “light” or “dark,” since, according to the Philosopher, it is not incongruous that the same name signify “man” to us and “not-man” to others. (Aristotle, Metaphysics 4.4, 1006b20.)

Others have said that light adds nothing beyond color but that the very manifestation of color is called “light” or “lucidity.” (On the ambiguity of the two Latin words for light, see the note at the beginning of the body of this article.) Avicenna disproves this position in many ways, (Avicenna, Liber de anima, pt. 4, ch. 1.) by examining all the ways in which it can be understood. Still, to the senses it appears to be false with regard to things that shine by night, whose color is hidden at night when their luminosity is apparent, while when their color is seen during the day, its luminosity is not sensed. But it is true that color is seen through light, since it makes color to be actually visible.

Others say that light does not have an existence that is stable and fixed in nature but is, rather, only an intention. (Regarding the scope of intentio, see note in d. 3, q. 1, a. 4. Here there is no perfect English equivalent. The sense seems to be a transitory form whose only being or purpose is to point or “tend toward” something else. This is the way color or light is understood to be in the air and ultimately in the eye as relating or orienting the sense power to the color as it exists in the colored object, and thereby causing vision. See also d. 19, q. 1, a. 3, ad 1.) For just as it is said that the species of color borne to the pupil through the air does not have natural existence in the air, but rather a spiritual existence (hence the species of whiteness and blackness are borne through the same part of the air), so also a luminous body’s intention left in the air is lucidity. This opinion is quite probable. First, since lucidity gives spiritual existence to color, it seems all the more that it has spiritual existence itself. The second reason is because no quality having natural existence can be seen when superimposed immediately on the organ of sight. But lucidity in contact with the pupil is seen. Hence it seems that it has spiritual existence.

But this does not seem to be completely true, since what has only intentional existence gives rise only to transmutation with regard to an activity of the soul, as in seeing and hearing. But we see sensibly that illumination gives rise to natural transmutations, through hotness following on rays of the sun. Hence it cannot be the case that it has only intentional existence.

Thus, others, with whom it seems to me we ought to agree, say that light is an accidental form having being that is fixed and firm in nature. As well, like heat, it is an active quality of fire, so luminosity is an active quality of the sun itself and is present in others to the degree that they communicate with the sun, which is the source of all lucidity. Hence Avicenna says (Avicenna, De caelo, ch. 14; the Latin De caelo text attributed to Avicenna is thought to be a spurious work.) that there is no action from the higher bodies on the lower, except through the mediation of light, just as fire acts through the mediation of heat. Hence luminosity and lucidity differ like heat in a subject that is essentially hot and in a subject that has been heated. Because the heavens are the first principle of alteration, it follows that every alteration in lower bodies is brought to completion by the power of light, whether it is an alteration with respect to natural being or with respect to the senses. By virtue of this, luminosity has the property of conferring generation on all bodies, as Dionysius says. For the same reason, it confers spiritual being on colors insofar as they receive being in a medium and in an organ. Hence lucidity itself also has spiritual power. So it also is that, according to Augustine, (Augustine, On the Literal Interpretation of Genesis, bk. 7, ch. 15 (CSEL 28.1:213; PL 34:363).) lucidity is the medium in every sense, though in sight it is so first of all and immediately. For visible qualities are prior to the rest, being found with respect to formal being in lower bodies insofar as they are compatible with a heavenly body, as is clear in On the Soul 2 and On Generation and Corruption 2, (Aristotle, On the Soul 2.7, 418b7–9; On Generation and Corruption 2.2, 329b14.) though they belong to the other senses by the mediation of other qualities.

Reply Obj. 1: Just as “darkness” is sometimes taken for darkened air, as has been said above, (Resp.) so also “light” is taken for a luminous body. In this way, we can understand that Augustine enumerates light along with other bodies after a manner of speaking, which is the way in which the Commentator also proves, in On the Soul 2 (Averroes, Commentary on Aristotle’s On the Soul, bk. 2, comm. 50.) that natural heat is a body. Nevertheless, Augustine does not intend to assert this as if it belongs to the faith, but rather as making use of what he had heard when studying philosophy. Thus, these authorities do not much compel us.

Reply Obj. 2: There is only understood to be a joining together and separation of luminosities with reference to the intensification or diminishing of lucidity due to the multiplication or subtraction of luminaries, whose rays are said to be blended on account of the distinction of luminaries.

Reply Obj. 3: This division of fire should be understood in the following way. By “light” is understood fire as it is in its proper matter, so that in this way, light is taken concretely. But by the others is understood fire as it is in a foreign matter: by “coal,” fire is understood as it is in something dry and earthy; by “flame,” as it is in something moist and airy. He himself explains it thus in the book On the Parts of Animals. (Aristotle, On the Parts of Animals 2.2, 649a20–30.) But even so, the authorities of Aristotle that are taken from the examples adduced are of no value, since he himself testifies at the beginning of On Generation and Corruption (See Aristotle, On Generation and Corruption 1.2, 316a5–14, where he discusses the physical versus the dialectical modes of inquiry.) that in those books he seeks not the subject but the mode. Hence he adduces them not to make an assertion, but rather because at his time they were held as probable by some.

Reply Obj. 4: According to Avicenna, (Avicenna, Liber de anima, pt. 4, ch. 1.) when a ray is said to “move” or to “descend,” this is not said properly, but rather metaphorically, namely, due to the fact that the alteration of illumination begins from that which is above us. In this way, too, we can say that heat “ascends” or “descends.”

Reply Obj. 5: A ray is not said to bounce off a solid body as if repulsed with respect to local motion like some sort of ball, but rather inasmuch as by its density the body creates an obstacle to illumination. In this way, too, other qualities are reflected.

Reply Obj. 6: The intersection of rays does not produce heat the way rubbing bodies together does. Rather, heat results because the concurrence of many rays at a single point multiplies the light, and this multiplies the heat inasmuch as light, since it is a quality of the first principle of alteration, aids alteration, especially with respect to that quality that is simply and most of all active, namely, heat. In this way, it is most in conformity with the power of the first principal of alteration.

Reply Obj. 7: Substantial form is reduced to act through the power of heaven. Thus, light that acts on lower bodies through the heavens must confer generation on things and move them to substantial form inasmuch as it acts by the power of the heavens itself, just as the heat of fire moves things toward the substantial form of fire insofar as it acts in the power of the substantial form from which it flows.

Reply Obj. 8: Luminosity, as well as lucidity, is in the genus of quality, as Avicenna says. (Avicenna, Liber de anima, pt. 3, ch. 1.) Because it entails an undergoing in the senses, it must be in the third species. Even so, it is not necessary for it to have a contrary, by virtue of the fact that it is a quality of that body that is naturally removed from contraries in such a way that it is universally the principle of motion and alteration.

Reply Obj. 9: The succession that is in the alteration of other qualities comes about from the fact that in the patient there is a contrary quality that resists the action of the one altering, a quality that must be pushed out successively. But since light does not have a contrary, as neither does a substantial form, something transparent receives lucidity instantaneously at the presence of something that illuminates, just as matter necessitated by the preceding alteration receives at once the substantial form. Thus, just as generation is the term of alteration, so also illumination is a local motion by which what illuminates becomes present to what is illuminated, as the Commentator says on the Physics 6. (Averroes, Commentary on Aristotle’s Physics, bk. 6, ch. 2.)

Reply Obj. 10: As Dionysius says, the light of the sun is received in different bodies in different ways according to their different capacity. (Pseudo-Dionysius, On the Divine Names, ch. 4 (PG 3:694).) Thus, there are some that are illuminated on their surface alone, such as opaque bodies. There are others that are illuminated in their depth as well, such as transparent bodies, which also do not retain luminosity because they receive their lucidity imperfectly, and hence the lucidity in them must cease with the absence of what illuminates. Finally, there are others that receive lucidity more perfectly and retain it, such as carbuncle and things of this sort.

Article 4

Whether the production of light is fittingly recounted

To the fourth we proceed as follows. (Parallel texts: ST I.67.4; 69.1.) It seems that the production of light is unfittingly recounted.

Obj. 1: For since God is light, it is not seemly for him to begin his works from darkness. But before light there was darkness. Therefore, it seems that light should be among the first created things, pertaining not to the work of distinction, but to the work of creation.

Obj. 2: Furthermore, light is found in more than one body, and there is not a single light belonging to all bodies. Therefore, it seems unfitting to describe the production of a single light alone, existing only in that place where the sun now is, as is said in the text of Scripture.

Obj. 3: Furthermore, day and night only existed through the approach and withdrawal of luminaries. But this can only be the case if light is carried in a circular motion. So, since the firmament, which is moved circularly, was made on the second day, it seems that day and night are unfittingly recounted on the first day in reference to the light created at that time.

Obj. 4: Furthermore, everything that comes to be from something, comes to be from what is incompatible with it, that is, its contrary, as is clear from the Physics 1. (Aristotle, Physics 1.5, 188b21–26.) But there is no contrary to the sun. Therefore, it cannot be the case that the sun was made from the light created at that time.

Obj. 5: Furthermore, as related in the Meteorology 2, (Aristotle, Meteorology 1.3, 340a25–341b10.) clouds are gathered together from vapors that, released from the earth and waters, ascend to up above. But higher bodies do not share in matter with lower bodies, as has been said. (Above: a. 1, ad 3.) Therefore, the light from which the sun, as if from matter, is said to have later come to be, could not have been a cloud.

On the contrary, there are the things said in the text. (Sent. II, 13.2(65)–3(66).2.)

I answer that, as has been said, (Above: a. 3, resp.) light is the active quality of a heavenly body, just as heat is the active quality of fire. But heat has a certain common action precisely as heat. For insofar as it is found in different things, its action is determined to determinate effects, as, for example, heat works for the conversion of food into human flesh in a man and into the substance of the plant in a plant. So, too, in the case of light, even though it has a given action following on the nature of light precisely as light, its action is still determined to different effects insofar as it is received in different things. Hence a ray of Saturn has an effect other than one of Jupiter.

Accordingly, I say that light itself, with respect to its common power, pertains to the work of distinction, just as heat does. But it is placed first among the works of distinction for the reason that it is the active quality of the first body. But later, determination to different effects in accord with different powers conferred on bodies pertains to the work of adornment. Thus, Dionysius says (Pseudo-Dionysius, On the Divine Names, ch. 4 (PG 3:699).) that sunlight is that light that Moses recounts on the first three days of our time, even though at that time it was formless, that is, because the determination of its power was not present.

Reply Obj. 1: Concerning this there are two opinions. Some say that the work of distinction began at once with the work of creation. Thus, light was created at once with the first created things. In this case, it is clear that the work of God did not begin from darkness. Indeed, we have to say this according to Augustine’s interpretation, even though Augustine is also of the opinion that the production of formless matter should be understood to have occurred prior to every day, not indeed by time but by nature. But others say that the work of creation was prior in time and that later, after an intervening space of time, light was formed and then the first day began. Hence they say that the work of creation came before every day. This agrees more with the text of Genesis in its plain sense. For immediately after indicating the act of creation, it mentions darkness over the face of the abyss and then later speaks of the production of light. Even so, it is not unfitting to place the preceding darkness in a genus other than privation. For there could not have been a privation prior to when the nature of the opposite disposition—namely, light—was bestowed on bodies; as, for example, a kitten before its ninth day is not said to be blind or deprived of sight. Hence the darkness preceding the light shows the imperfection of the bodily creation, though it does not have this imperfection from God, from whom it has whatever perfection it has. But it is appropriate for the divine works to be brought from imperfection to the perfect, as thus it is shown that every perfection comes from God. Hence Augustine says (Augustine, On the Literal Interpretation of Genesis, bk. 2, ch. 15 (CSEL 28.1:56; PL 34:276).) that if God is said to have made anything imperfect that he himself perfected at a later point, there is nothing reprehensible in this opinion.

Reply Obj. 2: The production of light (Although Aquinas uses both lux and lumen in this response, he does not appear to be emphasizing the distinct connotations of the terms, so we have rendered both as “light.” On the more technical meanings of these terms, see the note above in article 3.) implies that the properties of luminosity and transparency, which are traced back to the genus of light, had been conferred on all luminous bodies and transparent bodies. Even so, according to Dionysius, (Pseudo-Dionysius, On the Divine Names, ch. 4 (PG 3:694).) the sun is the principle and source of light, illuminating higher and lower bodies. Thus, by this light he understands the light of the sun as still formless at that time. The Master, too, says in the text (Sent. II, 13.3(66).1.) that from it the body of the sun was formed.

Reply Obj. 3: Concerning this there are two opinions. Damascene says (John Damascene, On the Orthodox Faith, bk. 2, ch. 7 (PG 94:887).) that on that day, day and night arose from the drawing in and sending forth of light, just as the sun withdrew its rays in the land of Egypt while there was light elsewhere, as is said in Exodus 10:23, and likewise, at the Passion of the Lord, when darkness was brought upon the face of the earth, as is related in Matthew 27:45. But this cannot be. For to illuminate is an action from a shining body that proceeds by a necessity of nature. Thus, it must always illuminate bodies directly opposite to it, unless, perhaps, we posit that it has coverings with which to cover itself, as the eyes have eyelids—which is ridiculous to say—or unless we posit that it comes about by divine power, as it were miraculously. And it is not fitting to posit this in the first establishment of nature, as Augustine says. (Augustine, On the Literal Interpretation of Genesis, bk. 2, ch. 1 (CSEL 28.1:32; PL 34:263).) Furthermore, the example of the Passion of Christ is not fitting. For that darkness was not caused by the withdrawal of the sun’s rays but rather by the interposition of the body of the moon, as Dionysius says in his 7th Letter to Polycarp, (Pseudo-Dionysius, Epistles 7, “To Polycarp” (PG 3:1082).) as also occurs during an eclipse of the sun, though it was not then the time for an eclipse and so it was miraculous.

Thus, others say, as is said in the text, (Sent. II, 13.3(66).2.) that day and night came about through the circular motion of that light, the motion by which it would approach and withdraw. Nor is it unfitting that the substances of the spheres, which cause the light to move in a circle, were made from the beginning of creation, and that later certain powers were conferred on them in the works of distinction and adornment. Or, if the substances of the spheres were not determined in their shapes, the luminous body itself naturally moved in a circular fashion, since it was of the nature of the fifth essence. Thus, it traced out a circular path by its motion, just as a stone by its motion makes a straight line even straighter than one drawn by human skill.

Reply Obj. 4: The substance of the body of the sun existed in its substantial form from the beginning of creation. Hence that luminous body itself was the substance of the sun. But the sun is said to have been made on the fourth day by reason of the addition of a new power, just as a man who is not musical is said to be made into a musician.

Reply Obj. 5: It was not a cloud in its true substance, but rather by having a similar property. For just as a luminous cloud receives light from the sun with less clarity than exists in the source itself, so also the substance of the sun first had imperfect light that later was brought to completion on the fourth day.

Article 5

Whether the Father does all things through the Son

To the fifth we proceed as follows. It seems that the Father does not do all things through the Son.

Obj. 1: For that through which something is done is related more immediately to the effect than the one who does the work through it. But the Son is not more immediately the principle of things than the Father, since both work equally immediately. Therefore, it does not seem that the Father works through the Son.

Obj. 2: Furthermore, “through” denotes the relationship of a cause. But the Son cannot be called a “cause” or “principle” with respect to anything that is in the Father. Therefore, the Son is not the one through whom the Father works.

Obj. 3: Furthermore, according to Damascene, (John Damascene, On the Orthodox Faith, bk. 2, ch. 3 (PG 94:874).) God’s thinking-out is his work. But it cannot be said that the Father is wise or intelligent through the Son. Therefore, it seems that neither does he work through the Son, since for God being is the same as working.

Obj. 4: Furthermore, “through” indicates an intermediate cause. But the Son is the first cause. Therefore, it seems that it is not fittingly said that the Father works through the Son.

On the contrary, it is said: whom he appointed the heir of all things, through whom also he created the world (Heb 1:2).

Furthermore, every artisan works through his art. But according to Augustine, (Augustine, In Iohannis evangelium tractatus, tract. 1 (CCSL 36; PL 35:1379).) the Son is the art of the Father, full of the accounts of living things. Therefore, the Father works through the Son.

I answer that to work through someone is spoken of in two ways. One way is as working through the power of someone, as a bailiff is said to work through the king, namely, through the king’s ruling power delegated to him, which is more immediate to the work than his own power. In this way, the Father is not said to work through the Son nor the Son through the Father, since both work by a single indivisible power. In the other way, someone is said to work through someone else as through one working. In this way, a king is said to work through a bailiff.

The reason for this distinction is that because working is a medium between the one working and the work worked, the causality implied by the preposition “through” can refer to working as proceeding from the one working, and in this case someone is said to work through one who is the cause of that person’s working, and is the one by whose power he works; or it can refer to working as terminated in the work worked, and in this case someone is said to work as a cause through that which is ordered by the one working to the work worked. Hence authority is designated in the one working with respect to the one through whom he works, in whom there is causality with respect to the work worked.

This occurs in two ways. One way is when that which is ordered by the one working as a cause of the work worked is its cause with reference to a power other than the power of the one working, though one that it receives from him. This must be an instrument of the one working inasmuch as it is moved by the one working, either by his command, as in the case of a slave, or by bodily motion, as in the case of inanimate things such as an ax. Hence the Philosopher says (Aristotle, Nicomachean Ethics 8.11, 1161b3.) that a slave is like an animate organ and that organs are like inanimate slaves. In this way, the Father does not work through the Son, as the heretics understood. The other way is when it works by the same power, though this is a power it receives from the one working. And in this way, we say that the Father does work through the Son, since he is the cause of the works worked together with the Father by a single and indivisible power, though he receives this power by being born of the Father.

Reply Obj. 1: Even though God works the effects of nature through natural causes, he nevertheless works immediately in all the effects of nature. Hence all the more does he work immediately in what he does through the Son, whose power is the same numerically as that of the Father.

Reply Obj. 2: The causality of the preposition does not refer to the one working, but to the work worked, as has been said. (Resp.)

Reply Obj. 3: When it is said “the Father understands,” nothing is connoted in respect of which the Son can be the principle. Thus, it cannot be said that the Father understands or knows through the Son, as it is said in things that imply an effect on a created thing.

Reply Obj. 4: The “first” is said to be that than which there is not something else prior. But the authority of the Father with respect to the Son, inasmuch as the Son has both being and working from the Father, by reason of which the Father works through the Son, does not make the Father greater than the Son or prior to him. Hence it does not follow that the Son is not the first cause because of the fact that the Father works through the Son.

Exposition of the text

Here it is to be noted that day is taken in different ways in Scripture. (Sent. II, 13.4(67).1.) Here he lays out the ways of taking “day.” One is as we speak of a natural day having twenty-four hours. This is the way in which we take: and there was evening and there was morning, one day (Gen 1:5). In another way, we speak of an artificial day, that is, the time when the sun is illuminating our hemisphere. And it is taken in this way when it is said that he called the light day and the darkness night (Gen 1:5).

This day began not from dawn, but from a full light. (Sent. II, 13.4(67).2.) It seems that this is false. For from full light, which is at noontime, up till the morning of the second day, there are not twenty-four hours. Thus, the first day would not have had as many hours as is said in the text. (Sent. II, 13.4(67)–5(68).4.)

To this we must say that on the first day it is said that the day did not have a dawn, not because the light that by its motion made day had not been created in the east, but rather because darkness was not combined with that first illumination as is now the case by virtue of the fact that dawn is now the end of night and the beginning of the day, which at that time did not occur.

It may also be taken in another way. (Sent. II, 13.7(70).5.) This explanation differs from the aforementioned in the fact that the aforementioned was taken with reference to the activity that the Son has from the Father. But this explanation is taken from the perspective of the one working, insofar as the Son, who is the one working, is from the Father.

For if the Father, according to his being Father, is the cause of the Son, much more is he the cause of those things which were made through the Son. (Sent. II, 13.7(70).5, quoting John Chrysostom, Expositio ad Hebraeos, homily 2, n. 2.) Here Chrysostom speaks in a common and improper manner. For cause is not properly received in the divine persons. Rather, we use the name “principle” to signify the origin of persons. This was discussed in Book I.