Lecture 44 — Science compared with other modes of knowing

b30. Scientific knowledge and its object differ from opinion and the object of opinion

b31. in that scientific knowledge is commensurately universal and proceeds by necessary connexions, and that which is necessary cannot be otherwise.

b33. So though there are things which are true and real and yet can be otherwise, scientific knowledge clearly does not concern them: if it did, things which can be otherwise would be incapable of being otherwise. Nor are they any concern of rational intuition — by rational intuition I mean an originative source of scientific knowledge — nor of indemonstrable knowledge, which is the grasping of the immediate premise. Since then rational intuition, science, and opinion, and what is revealed by these terms, are the only things that can be ‘true’, it follows that it is opinion that is concerned with that which may be true or false, and can be otherwise: opinion in fact is the grasp of a premise which is immediate but not necessary.

a5. This view also fits the observed facts, for opinion is unstable, and so is the kind of being we have described as its object.

a7. Besides, when a man thinks a truth incapable of being otherwise he always thinks that he knows it, never that he opines it. He thinks that he opines when he thinks that a connexion, though actually so, may quite easily be otherwise; for he believes that such is the proper object of opinion, while the necessary is the object of knowledge.

a11. In what sense, then, can the same thing be the object of both opinion and knowledge? And if any one chooses to maintain that all that he knows he can also opine, why should not opinion be knowledge? For he that knows and he that opines will follow the same train of thought through the same middle terms until the immediate premises are reached; because it is possible to opine not only the fact but also the reasoned fact, and the reason is the middle term;

a16. so that, since the former knows, he that opines also has knowledge. The truth perhaps is that if a man grasp truths that cannot be other than they are, in the way in which he grasps the definitions through which demonstrations take place, he will have not opinion but knowledge: if on the other hand he apprehends these attributes as inhering in their subjects, but not in virtue of the subjects’ substance and essential nature possesses opinion and not genuine knowledge; and his opinion, if obtained through immediate premises, will be both of the fact and of the reasoned fact; if not so obtained, of the fact alone.

a23. The object of opinion and knowledge is not quite identical; it is only in a sense identical, just as the object of true and false opinion is in a sense identical. The sense in which some maintain that true and false opinion can have the same object leads them to embrace many strange doctrines, particularly the doctrine that what a man opines falsely he does not opine at all. There are really many senses of ‘identical’, and in one sense the object of true and false opinion can be the same, in another it cannot. Thus, to have a true opinion that the diagonal is commensurate with the side would be absurd: but because the diagonal with which they are both concerned is the same, the two opinions have objects so far the same: on the other hand, as regards their essential definable nature these objects differ. The identity of the objects of knowledge and opinion is similar. Knowledge is the apprehension of, e.g., the attribute ‘animal’ as incapable of being otherwise, opinion the apprehension of ‘animal’ as capable of being otherwise — e.g., the apprehension that animal is an element in the essential nature of man is knowledge; the apprehension of animal as predicable of man but not as an element in man’s essential nature is opinion: man is the subject in both judgements, but the mode of inherence differs. This also shows that one cannot opine and know the same thing simultaneously; for then one would apprehend the same thing as both capable and incapable of being otherwise — an impossibility. Knowledge and opinion of the same thing can co-exist in two different people in the sense we have explained, but not simultaneously in the same person. That would involve a man’s simultaneously apprehending, e.g., (1) that man is essentially animal — that is, cannot be other than animal — and (2) that man is not essentially animal, that is, we may assume, may be other than animal.

Further consideration of modes of thinking and their distribution under the heads of discursive thought, intuition, science, art, practical wisdom, and metaphysical thinking, belongs rather partly to natural science, partly to moral philosophy.

b6. Quick wit is a faculty of hitting upon the middle term instantaneously. It would be exemplified by a man who saw that the moon has her bright side always turned towards the sun, and quickly grasped the cause of this, namely that she borrows her light from him; or observed somebody in conversation with a man of wealth and divined that he was borrowing money, or that the friendship of these people sprang from a common enmity. In all these instances he has seen the major and minor terms and then grasped the causes, the middle terms. Let A represent ‘bright side turned sunward’, B ‘lighted from the sun’, C the moon. Then B, ‘lighted from the sun’ is predicable of C, the moon, and A, ‘having her bright side towards the source of her light’, is predicable of B. So A is predicable of C through B.

Scientific knowledge and its object. After comparing sciences with one another from the viewpoints of certitude, of unity and of diversity, the Philosopher here compares science to everything else that pertains to knowledge.

And his treatment falls into two parts.

In the first he treats of the comparison of science to opinion, which bears on the true and false.

In the second, of the comparison of science to those habits of knowledge which are concerned exclusively with the true, at: further consideration of modes (90a23; [405]).

The first part is divided into two parts.

In the first he determines the truth.

In the second he excludes a doubt, at: in what sense, then (90a11; [402]).

Concerning the first he does three things.

First, he lays down the difference between science and opinion.

Second, he shows what pertains to science, at: in that scientific knowledge (89b31; [396]).

Third, what pertains to opinion, at: so though there are things (89b33; [397]).

He says therefore first (89b30) that science differs from opinion; in like manner the scientifically knowable, which is the object of science, differs from the opinable, which is the object of opinion.

Then he shows what pertains to science, setting down two things which pertain to it, at: in that scientific knowledge (89b31).

One of these is that it is of the universal, for science is not concerned with singulars which fall under sense. (He explained this above). The other is that science is obtained in virtue of necessary things. And he explains that the necessary is that which cannot be otherwise. This, too, was explained above, namely, that demonstration proceeds from necessary things.

Then he shows what pertains to opinion, namely, that it is concerned with things that could be otherwise, either universally or particularly, at: so though there are things (89b33).

This he proves in three ways.

First, by way of a division, saying that in addition to necessary truths, which cannot be otherwise, there are non-necessary truths, which could be otherwise. Now, from what has been said above, it is clear that science is not concerned with the latter, because it would follow that contingent things would be such as could not be otherwise. For science is concerned with such things, as has been said. Similarly, it cannot be said that understanding is concemed with them. “Understanding” is taken here not as a faculty [power] of the soul, but as being the principle of science, that is, as the habit of first principles, from which demonstration proceeds in causing science. Hence in explaining what that understanding is which is the principle of science he adds, “Nor of indemonstrable knowledge” (88b37), that is, not of facts that could be otherwise. As if to say: understanding is nothing more than a science of the indemonstrable. For just as science implies certainty of knowledge acquired through demonstration, so understanding implies certitude of knowledge without demonstration; not because of a shortcoming in some demonstration, but because that about which this certainty is had, is indemonstrable and per se known. Therefore, to explain this he adds that demonstrative science is nothing else than the certain intuition of an immediate proposition. But that understanding is science of the indemonstrable is clear from the fact that he says that it is "the principle of science". For since science is concerned with the necessary, and the necessary is not concluded except from the necessary, as has been proved above, it is required that understanding, which is the principle of science, not be concerned with contingent things.

Having shown, therefore, that neither science nor understanding is concerned with contingent things, he sets down a division and says that understanding and science and opinion happen to be true as that does which is stated by them, that is, which is verbally stated by understanding and science and true opinion. For the true is found both in the intellect’s act of composing and dividing and in the outward expression of this act insofar as it signifies the inward truth of the opinion or science or understanding. Therefore, if every truth belongs either to understanding or science or opinion, and there are some contingent truths, and they belong neither to science nor understanding, what is left is that opinion is concerned with them, whether they be actually true or actually false, provided that they could be other than they are.

In order to elucidate what opinion is, he adds that opinion is the acceptance, that is, the grasping, of a proposition that is immediate and not necessary. And this can be understood in two ways: in one way, so that the immediate proposition in itself is indeed necessary, but it is accepted by opinion as non-necessary; in another way, so that it is in itself contingent. For an immediate proposition is one that cannot be proved through a middle, whether it be a necessary proposition or not. For it has been shown above that there is no process to infinity in predications, neither on the part of the middles nor on the part of the extremes. And this was shown not only analytically in demonstrations, but also logically in general as to syllogisms. Therefore, if there be a contingent proposition which is mediate, it must be reduced to others that are immediate. However, it is not reduced to necessary immediate propositions, because necessary things are not the proper principles of contingent things, nor can contingent things be concluded from necessary things. Hence what remains is that some contingent, propositions are immediate and some mediate. Thus, “The man does not run,” is mediate, for it can be proved through this middle, “The man is not in motion,” which is also contingent, albeit immediate. The acceptance of such immediate contingent propositions is opinion. Yet this does not mean that the accepting of a mediate contingent proposition is not opinion. For opinion is related to contingent things, as science and understanding to necessary things.

Second, he proves the same point by means of that which is commonly observed, at: this view also fits (90a5).

He says that what has been said, mainly, that opinion is concerned with the contingent is confessed, that is, in agreement with things that are observed. For opinion seems to denote something weak and uncertain and to be of such a nature that weakness and uncertainty are in it.

Third, he proves the same point by experiment, at: besides, when a man (90a7).

For no one, when he thinks that it is impossible for a thing to be otherwise, supposes that he is forming an opinion; rather he considers himself to know scientifically. But when he thinks that something is so and that there is nothing to prevent its being otherwise, then it is that he considers himself to have opinions. This would indicate that opinion concerns such things, that is, contingent things, but science necessary things.

Then he raises a doubt concerning the aforesaid, at: in what sense, then (90a11).

First, he raises the doubts.

Second, he solves them, at: so that, since the former (90a16; [403]).

Concerning the first (90a11), he presents two doubts.

One of these is concerned with the opinable and the scientifically knowable. If opinion is concerned with the contingent and science with the necessary, and the contingent is not the same as the necessary, a doubt remains as to how a man can opine and scientifically know the same thing.

The second doubt concerns science and opinion, namely, why opinion is not science; supposing, of course, that one claims that there can be opinion about every known thing. For in regard to everything known a man can opine that it could be otherwise (except perhaps in the case of first principles per se known, whose contraries cannot be conceived, and concerning which there is not science but understanding). But in regard to all mediate truths of which there is demonstration and science, someone can suppose that it is possible that they could be otherwise. Consequently, they can fall under opinion. For opinion is not concerned exclusively with things contingent in their very nature, because then a man could not have opinion about everything he knows. Rather, opinion is concerned with that which is accepted as possible to be otherwise, whether it is that or not.) Therefore, on this supposition, it remains that science and opinion are the same, because both the scientific knower and the man of opinion acquire science and opinion through middles until they reach things which are immediate, as is clear from the foregoing. Hence if someone proceeds through middles to immediate propositions he has science. Now, this is what the man of opinion does, because just as it is possible to have an opinion 'that' something is so, it is also possible to have an opinion 'why' something is so. But when I say, 'why', a middle is implied. Hence it is clear that opinion can proceed to immediates through a middle, whether opinion be of things that are contingent in their very nature, or of things accepted as contingent.

Then he solves the aforesaid doubts, at: so that, since the former (90a16).

First, he solves the second one which is concerned with the identity of science and opinion.

Second, he solves the first one which is concerned with the identity of the scientifically knowable and the opinable, at: the object of opinion (90a23; [404]).

He says therefore first (90a16) that if someone proceeds through middles to immediates in such a way that the middles are not considered capable of being otherwise, but are considered to behave as definitions which are the middles through which demonstrations proceed, there will not be opinion but science. But if someone proceeds to the immediates through certain true middles which, nevertheless, are either not verified of the things of which they are said per se (as definitions which are predicated essentially or signify the species of a thing)—or he does not take them as being in these things per se, then he will have opinion and will not truly know the 'quia' and the 'propter quid' at once, even if he proceeds as far as the immediates: for then he will be forming an opinion through the immediates and will not know scientifically. But if he does not proceed through immediates but through mediates, then he will not be forming an opinion bearing on the 'propter quid' but only the 'quia'. For even scientific knowledge, when it is not propter quid and immediate, is not 'propter quid' science but 'quia'.

Then he solves the first doubt which concerns the identity of the scientifically known and the object of opinion, at: the object of opinion (90a23).

Here it should be noted first of all that it is not unfitting that what is scientifically known by one person be a matter of opinion for another, because what one takes as impossible to be otherwise than stated and as scientifically known, another might take as possible to be otherwise and as a matter for opinion. But to say that the same man has opinion and scientific knowledge of the same thing at the same time, is not entirely true, but only in a way. For just as there can be true and false opinion about the same thing somehow but not absolutely, so also in regard to opinion and scientific knowledge. For if someone were to say that there could be a completely true and completely false opinion about the same thing, as some do say (for example, those who said that whatever seems to be true to a person is true, as it is stated in Metaphysics IV), then a person who would say such a thing would be forced to admit certain absurdities and the many other things (pointed out in Metaphysics IV which follow from stating that the same thing is true and false.) In particular this absurdity would follow, namely, that no opinion is false and that what he opined to be false he did not opine. Hence it cannot be said that there is true and false opinion of the same thing absolutely.

But because “same” is said in many ways, it happens that somehow there is true and false opinion about a same thing, and somehow not. For if “a 'same' thing about which there are opinions” means the same real extramental subject, then there can be true and false opinion about a same thing. But if 'same' refers to the proposition that is opined, then it is impossible. For example, to opine that the diagonal is commensurable with the side of a square is to opine with a false opinion; and it is absurd to say that this statement can be opined as a true opinion. But if we take diagonal as the enunciable subject, then there can be true and false opinion of a same thing. For in regard to a diagonal, one opines truly that it is really incommensurable, and another opines falsely that it is commensurable. Thus, it is clear that although that concerning which there is science and opinion be the same in subject, it is not the same in notion. For the diagonal which is said to be commensurable and not to be commensurable is the same in subject, because the subject of each statement is the same. Nevertheless, it is clear that there is a mental distinction between diagonal insofar as it is taken as commensurable and insofar as it is taken as incommensurable. Consequently, there can be true and false opinion about the same subject, but not of the same subject according to notion.

It is similar in the case of science and opinion. For it is science when someone knows this to be an animal in such a way that it cannot not be an animal; but it is opinion when someone knows it to be an animal in such a way that it might not be an animal. For example, if there is science concerning the fact that man is truly that which is an animal in such a way that it is impossible for it to be otherwise, there will be opinion concerning the fact that man is not truly that which is an animal, and as a result could be otherwise. For it is clear that the subject both known and opined is the same, namely, man; but in notion it is not the same.

Thus, therefore, from the foregoing it is obvious that it is impossible to know scientifically and to opine the same thing at the same time, because a man would at one and the same time have a conjecture that could be otherwise and that could not be otherwise. But this could occur in the case of two men, namely, that one have science about a thing and another have opinion about the same thing, as has been stated. But this does not occur in the same person for the reason given.

Then, at: further consideration (90a23) he compares science to certain habits that are concerned with truth.

First, to those habits which deal with principles and conclusions.

Second, to the habit which is specifically concerned with the middle, at: quick wit is a faculty (90b6; [406]).

He says therefore first (90a23) that in regard to those forms of knowledge that are other than opinion, the question of how they are distinguished into reason and understanding and science and art and prudence and wisdom, pertains somehow to the considerations of first philosophy or even of natural philosophy and somehow to the considerations of moral philosophy which is called ethics.

To understand this it should be noted that in Ethics VI, Aristotle lays down five things which are always concerned with the truth, namely, art, science, wisdom, prudence and understanding, adding two that are concerned with the true and false, namely, suspicion and opinion. Now, the first five are concerned solely with the true, because they imply rectitude of reason. But three of them, namely, wisdom, science and understanding imply reason’s rectitude in regard to necessary truths: science in regard to conclusions, understanding in regard to principles, and wisdom in regard to the highest causes, which are the divine causes. But the other two, namely, art and prudence, imply the rectitude of reason in regard to contingent things: prudence in regard to things to be done, that is, in regard to acts which remain within the one acting, such as to love, hate, choose, and similar acts that pertain to moral activity, of which prudence is the director. Art, however, implies the rectitude of reason in regard to things to be made, that is, things that are done to external matter; for example, cutting and other activities in which art directs. To this list he adds “reason,” which pertains to bringing, principles to their conclusions. Now, to treat of wisdom, namely, what it is and how it works, and to treat of science and understanding and art, pertain somehow to first philosophy. Prudence, on the other hand, pertains to moral consideration; understanding and reason, insofar as they name certain powers, pertain to natural consideration, as is clear in On the Soul.

Then he makes mention of the habit which is specifically concerned with the middle, at: quick wit is a faculty (90b6).

And he says that quick wit is a certain accurate and facile conjecturing of the middle (the reason) why something occurs; and this when one does not have much time to inspect or deliberate, as when a person, seeing that the moon has all its brightness whenever it is turned toward the sun, immediately understands why this is, namely, because it is illumined by the sun. Similarly, in the case of human acts: if a person sees a poor man arguing with a rich man, he knows that the rich man took something from him, and the argument is about its return. Or if he should see persons formerly enemies now made friends, he knows that the reason is because both have a common enemy. Second, he shows in two ways that to know the middle is to know the 'why': first, with the following reason, namely, because such a quick witted person, seeing all the middle causes, knows all the ultimate ones into which they are all finally analyzed, and through which the 'why' is known.

Second, he manifests this with an example presented in a syllogism. Thus, let us suppose the moon to be C, that is, the minor extreme, and “to be bright because of its opposition to the sun,” to be A. the major extreme; but “to be illumined by the sun,” to be B, that is, the middle. For C is B. that is, “The moon has light from the sun,” and A is in B, because “that which has light from the sun is bright when turned toward the sun.” Thus it is proved that A is in C through B. Hence it is clear that quick wit is the faculty of quickly apprehending the middle, and is present in persons as a natural gift or is acquired by training. But he presented various examples of quick wit to show that in all the aforesaid habits, namely, prudence, wisdom, and so on, there can be quick wit.