Commentaria in Summam contra Gentiles, Liber III

The fourth doubt ¹ is: because, given divine providence, chance and fortune seem to be excluded. For what is foreseen is not fortuitous or by chance, since these happen outside the intention of the agent. If, therefore, all things that occur in the universe are foreseen, it follows that nothing will happen by chance and fortune.

I. To remove this, however, St. Thomas lays down this conclusion: Divine providence does not remove chance and fortune from things.

It is proved first. If nothing occurred by chance and fortune, nothing would occur in the fewer cases. Therefore all things would happen of necessity. But this is contrary to the nature of divine providence, as was shown above. Therefore etc. — The antecedent is proved. Because fortune and chance are spoken of ² in those things that happen in the fewer cases. — The first consequence, indeed, is proved. Because those things that are contingent in the greater number of cases differ from necessary things by this alone, that they can fail in the fewer cases.

2. Note, regarding the first consequence and its proof, that since there are three kinds of effects: namely, certain ones that always proceed from their cause, which are called necessary; certain ones that happen for the most part, like the effects of lower natural causes, which are called contingent in the greater number of cases; and certain ones that happen rarely and in the fewer cases from their cause, like monsters, which are called rarely contingent: — if rarely contingent things are removed, it is necessary that things contingent in the greater number of cases are also removed, because rarely contingent things arise from the fact that some causes are hindered sometimes, but rarely, from producing their effects; and from the fact that a cause is hindered sometimes but rarely, it follows that it produces its effects for the most part. And thus, that there are things contingent in the greater number of cases follows necessarily from the fact that things contingent in the fewer cases are posited, and vice versa. Therefore also, one being removed, the other is also removed, and vice versa: just as happens in convertible terms. But when things contingent in the fewer cases and things contingent in the greater number of cases are removed, it follows that those things alone exist among beings that always happen, which are said to happen of necessity. Therefore St. Thomas very well infers that, if nothing happens in the fewer cases, all things happen of necessity.

3. But a doubt arises. For someone could say that besides things contingent in the greater number of cases and things contingent in the fewer cases, there are also things contingent either way, such as those that proceed from the will. Therefore, although it be posited that nothing is by chance and in the fewer cases, and consequently that nothing is for the most part, it does not follow that all things are of necessity, but some things could be contingent either way. He answers, from the doctrine of St. Thomas on II Phys., lect. 8; and this is according to the mind of Averroes on the same passage, comment 48; that from a cause contingent either way nothing proceeds unless it is determined to one by something, since it is in potency. Therefore, that it may be able to go forth into act and produce some effect, it must either produce it for the most part, or in the fewer cases. And thus it must be that the effect proceeding from a cause that is open either way, considered in itself, proceeds either in the greater number of cases or in the fewer: and no effect is contingent either way as it is apt to be brought forth into act, since it does not proceed from it except insofar as it is determined to one; for from a cause open either way, insofar as it is open either way, no effect can proceed. For this reason it very well follows that, if nothing happens in the greater number of cases, and nothing in the fewer cases, all things always happen of necessity.

II. Secondly. It would be contrary to the nature of providence if things subject to providence did not act for the sake of an end, since it belongs to providence to order all things to an end. It would also be contrary to the perfection of the universe if there were no corruptible thing, and no power able to fail. Therefore, also, if there were no things by chance, it would be contrary to the nature of providence and contrary to the perfection of the universe. — The consequence is proved. Because from the fact that something acting for an end fails from what it intends, it follows that some things happen by chance.

III. Thirdly. From the order of divine providence and disposition proceeds the multitude and diversity of causes. But the disposition of causes being supposed,³ it is necessary that sometimes one is hindered or helped by another to produce an effect. But from the concurrence of several causes it happens that something occurs by chance, when an unintended end results: as the finding of a debtor by one who goes to the market not for this reason. Therefore divine providence does not exclude things by chance. Observe that from the concurrence of several causes it happens that something occurs by chance in comparison to one of those concurring causes, or in comparison to both, when something happens outside the intention of either one of them or of both: as when someone goes to the market to find a debtor, but the debtor goes to the market not to be found by the creditor, but to buy something, the finding of the debtor by the creditor is by chance in comparison to the debtor only, because it happened outside his intention; but when two servants are sent by a master so that they meet each other while they are ignorant of this, the meeting of the two servants who did not intend to meet each other is by chance with respect to both. But in comparison to a higher cause ordering the concurrence of such causes, and the effect proceeding from their concurrence, the concurrence itself, or the effect proceeding from it, is not said to be by chance, since it is not outside its intention, but is intended. Wherefore St. Thomas says in the First Part, q. xxii, a. 2, ad 1, that with respect to the universal cause no effect is said to be by chance, since nothing can be withdrawn from its order.

2. But a doubt arises. For St. Thomas seems to state contradictories when he says that something happens by chance when an unintended end results. For it is of the ratio of an end that it be intended: for it is that for the sake of which something is done.⁴ Therefore it is repugnant that something be an end, and yet not be intended. He answers that an end can be taken in two ways: in one way, materially, namely, as to the very thing absolutely that terminates the action; in another way, formally, namely, for the thing that terminates the action as it has the ratio of a final cause. In the second way, it is repugnant that something be an end, and not be intended. But in the first way, it is not repugnant. And in this way St. Thomas's saying is understood: for it is clear that a fortuitous effect, as such, is not the end of the action that it terminates except materially.

IV. Fourthly. For the perfection of things it is required that there be not only per se beings, but also per accidens beings. Therefore for their perfection it is required that there also be certain per accidens causes. Therefore it is not contrary to providence, which preserves the perfection of things, that some things happen by chance. The antecedent is proved. Because, since things do not have ultimate perfection in their substance, it is necessary that they attain some through accidents, and sometimes through several. But from this it follows that there is per accidens being: since subject and accident, and also several accidents of one subject, are one and a being per accidens. — The first consequence, indeed, is proved. Because, since what is not cannot be the cause of anything, it must be that according as each thing is related to being, so it is related to this, that it is a cause. And consequently, according to the diversity of order in beings there is also a diversity of order in causes. — The second consequence, indeed, is proved. Because those things that proceed from some causes per accidens are said to happen by chance or by fortune.

2. A doubt occurs concerning the assumption for the proof of the second consequence. Because it does not seem universally true that those things that happen from causes per accidens are by chance or by fortune. For when we say that the musical builds, we do not say that the house is made by chance or by fortune: and so of many other things. He answers that it is not St. Thomas's intention to say that all things that happen per accidens are by chance or by fortune: but that some things that happen per accidens from some causes, namely, those that are outside the intention of the agent and are joined in the fewer cases to the per se effect, proceed from chance and fortune.

V. Concerning that proposition, According as each thing is related to being, so it is related to this, that it is a cause, it is doubted. For the white has being per accidens, and yet it is the per se cause of the dispersing of sight. — There are also many other causes that have being per se, and yet are per accidens causes of something happening outside their intention. He answers that this proposition is understood to mean that every cause has such a mode of causality as it has a mode of being, so that the mode of causing and the mode of being of the cause correspond proportionally to each other. And it is understood not of any being whatsoever, but of that according to which causality is attributed to the thing. For if that being belongs to the thing per se, the causality also will belong to it per se: but if it belongs to it per accidens, the causality also will belong to it per accidens. And just as it is said of these modes per se and per accidens, so it is understood of other modes of being and causing: for instance, of primary and secondary, of by which (quo) and which (quod).

2. When, however, it is said first, that the white has being per accidens, and yet disperses per se: — it is answered that by the name "the white" we can understand two things: namely, either whiteness itself, according as it has being in a subject; or the subject itself informed by whiteness, for instance, wood or a wall. If we understand whiteness itself, it is denied that it has being per accidens, namely, as though it were a certain being per accidens; on the contrary, it is a being per se, as being per se is opposed to being per accidens, but not as it is opposed to being in another; for it is a certain nature, determined to one genus and to one species. And similarly it is the per se cause of dispersing: because this proposition is per se, The white disperses. — If, however, we understand the subject informed by whiteness, as when we say that wood or a wall disperses: thus it is said that the white disperses per accidens, and not per se. For just as the white is predicated per accidens of wood, as is clear in V Metaph., the chapter on Being,⁵ so also dispersing is predicated per accidens of it. And thus a stone has being white per accidens, and per accidens causes the dispersing of sight: because it does this insofar as it happens to it to be white.

3. When it is said secondly that many causes having being per se are causes per accidens: — it is denied, speaking of the being by reason of which causality is attributed to it. For just as one digging a grave finds a treasure per accidens, and is called a cause of that finding per accidens, so he has some being per accidens by reason of which this causality is attributed to him per accidens: for this belongs to him insofar as he is a finder of treasure, but to be a finder of treasure happens to one digging a grave as such; for this proposition, One digging a grave is a finder of treasure, is per accidens. Similarly in other causes per accidens, causality always follows some being per accidens: namely, the per accidens predication of something concerning that to which causality is attributed. For in this way being per accidens is taken by Aristotle in V Metaph.,⁶ namely, when one thing is predicated of another per accidens. And this whether it is taken per accidens on the part of the cause only, namely, when that which happens to the per se cause is called a per accidens cause; or it is taken on the part of the effect, namely, when something unintended is joined to the per se effect; for even then it is necessary that something be predicated per accidens of the per se cause of the other effect, from which such an effect is attributed to that cause per accidens.

VI. Fifthly. It belongs to the order of divine providence that there be an order and gradation in causes. But the higher any cause is, the greater is its power, and consequently its causality extends to more things. Therefore the order of divine providence requires that there be a higher cause which extends to more things than a lower cause. Therefore it also requires that something happen outside the intention of a lower and particular cause. Therefore also that there be chance and fortune.

The second consequence is proved. Because, since the intention of no cause extends beyond its power, because it would be in vain, as not being able to be fulfilled through the cause itself; the intention of a particular cause does not extend to all things that can happen, namely, from a higher cause; and consequently some things can happen outside its intention. — The third consequence, indeed, is proved. Because something happens by chance or fortuitously from the fact that some things happen outside the intention of agents.

Observe that in this deduction some propositions have been interposed which St. Thomas did not state, aiming at brevity. For this was done because he manifestly gives them to be understood; and they are required for a complete and formal deduction.

The conclusion is confirmed by the authority of Eccl. ix: I saw that the race is not to the swift, but time and chance happen to all things. St. Thomas explains, namely, in lower things.