Here is a new translation of Question 86 of Thomas Aquinas Summa Theologiae, where he argues that a singular 'proposition' (a proposition being what we now call a sentence) does not express what we now call a singular proposition.
The modern view of the proposition is that it is a complex or 'structured' entity that is expressed by a sentence, and that a singular proposition such as 'Socrates is a man' consists of the object referred to by the proper name 'Socrates', namely Socrates himself, plus the concept referred to by the predicate 'is a man'. This was not the traditional view at all. On the traditional view, concepts are universal only, and the only kinds of propositions are so-called particular propositions such as 'some man is wise', or universal propositions such as 'all men are mortal'. Both kinds of proposition combine universal terms such as 'man', 'wise', 'mortal' and so on. See here, for example, for a reasonably accurate account of the traditional view of the proposition.
Singular propositions do not therefore exist as such in the traditional logic, although logicians after the scholastic period (such as Arnauld) treated them as universal propositions. Aquinas did not regard them, in our sense, as propositions at all. There are singular sentences, such as 'Socrates is wise'. But there is no proposition, in our sense, expressed by this sentence. Aquinas explains that (following Aristotle) the intellect only understands universal concepts such as 'man', 'mortal' and so on, by abstracting from the 'intelligible species' in perception. The intellect can only understand singulars in an indirect way, by what he calls 'turning round to sense-appearances'.
This passage was mentioned by Geach in the book Mental Acts, published in 1957.
The problem I have just been discussing - how we judge about sensible particulars - was much agitated in the Middle Ages; and in my solution of it I believe I am following Aquinas. Aquinas' expression for the relation of the 'intellectual' act of judgment to the context of sense-perception that gives it a particular reference was 'conversio ad phantasmata', 'turning round towards the sense-appearances'. This metaphorical term is obviously a mere label, with negligible explanatory value; but it does not pretend to be more than a label. Aquinas has, in my opinion, at least rightly located the problem; the problem is not how we advance from judgments like this is before that to more general judgments, but contrariwise how a judgment inherently general can be tied down to referring to particular things.
The problem of singular propositions, in my view, still requires a decent explanation. But enough of that.
| Latin | English |
|---|---|
| IȘ q. 86 pr. Primo, utrum cognoscat singularia. | First, we consider whether our intellect knows singular things. |
| IȘ q. 86 a. 1 arg. 1 Ad primum sic proceditur. Videtur quod intellectus noster cognoscat singularia. Quicumque enim cognoscit compositionem, cognoscit extrema compositionis. Sed intellectus noster cognoscit hanc compositionem 'Socrates est homo', eius enim est propositionem formare. Ergo intellectus noster cognoscit hoc singulare quod est Socrates. | Objection 1. It would seem that our intellect knows singulars. For whoever knows a a thing composed of terms, knows the terms of the thing which is composed. But our intellect knows 'Socrates is a man', which is composed of terms: for it is [in the nature] of the intellect to form a proposition. Therefore our intellect knows the singular object Socrates. |
| IȘ q. 86 a. 1 arg. 2 Praeterea, intellectus practicus dirigit ad agendum. Sed actus sunt circa singularia. Ergo cognoscit singularia. | Objection 2. Further, the practical intellect directs us towards action. But actions concern singular things. Therefore the intellect knows singulars. |
| IȘ q. 86 a. 1 arg. 3 Praeterea, intellectus noster intelligit seipsum. Ipse autem est quoddam singulare, alioquin non haberet aliquem actum; actus enim singularium sunt. Ergo intellectus noster cognoscit singulare. | Objection 3. Further, the intellect understands itself. But it itself it is a kind of singular, otherwise it would not have some action; for actions are of singulars. Therefore our intellect knows the singular. |
| IȘ q. 86 a. 1 arg. 4 Praeterea, quidquid potest virtus inferior, potest superior. Sed sensus cognoscit singulare. Ergo multo magis intellectus. | Objection 4. Furthermore, whatever can be done by an inferior power, a superior power can do. But sense knows the singular, much more, therefore, the intellect. |
| IȘ q. 86 a. 1 s. c. Sed contra est quod dicit philosophus, in I Physic., quod universale secundum rationem est notum, singulare autem secundum sensum. | On the contrary, there is what the Philosopher says (Phys. i, 5), that the universal is known according to reason, but the singular according to sense.' |
| IȘ q. 86 a. 1 co. Respondeo dicendum quod singulare in rebus materialibus intellectus noster directe et primo cognoscere non potest. Cuius ratio est, quia principium singularitatis in rebus materialibus est materia individualis, intellectus autem noster, sicut supra dictum est, intelligit abstrahendo speciem intelligibilem ab huiusmodi materia. Quod autem a materia individuali abstrahitur, est universale. Unde intellectus noster directe non est cognoscitivus nisi universalium. | I answer saying that our intellect cannot know the singular in material things directly and primarily. The reason of this being that the principle of singularity in material things is individual material, whereas our intellect, as was said above (Ia Q85, 1), understands by abstracting the intelligible species from such material. Now what is abstracted from individual material is the universal. Hence our intellect knows directly the universal only. |
| Indirecte autem, et quasi per quandam reflexionem, potest cognoscere singulare, quia, sicut supra dictum est, etiam postquam species intelligibiles abstraxit, non potest secundum eas actu intelligere nisi convertendo se ad phantasmata, in quibus species intelligibiles intelligit, ut dicitur in III de anima. Sic igitur ipsum universale per speciem intelligibilem directe intelligit; indirecte autem singularia, quorum sunt phantasmata. Et hoc modo format hanc propositionem, Socrates est homo. | But indirectly, and as if by a kind of reflection, it can know the singular, because, as was said above (Ia Q85, 7), even after abstracting the intelligible species, the intellect cannot understand them actually without turning to the phantasms in which it understands the intelligible species, as is said De Anima iii, 7. Therefore the universal itself it understands directly through the intelligible species; but the singulars indirectly, of which are the phantasms. And in this way it forms the proposition 'Socrates is a man'. |
| IȘ q. 86 a. 1 ad 1 Unde patet solutio ad primum. | Wherefore the reply to the first objection is clear. |
| IȘ q. 86 a. 1 ad 2 Ad secundum dicendum quod electio particularis operabilis est quasi conclusio syllogismi intellectus practici, ut dicitur in VII Ethic. Ex universali autem propositione directe non potest concludi singularis, nisi mediante aliqua singulari propositione assumpta. Unde universalis ratio intellectus practici non movet nisi mediante particulari apprehensione sensitivae partis, ut dicitur in III de anima. | Reply to Objection 2. The choice of a particular thing to be done is as if the conclusion of a syllogism of the practical intellect, as is said Ethic. vii, 3. But from a universal proposition cannot be directly concluded a singular proposition, except through the medium of a singular proposition that is assumed. Therefore the universal principle of the practical intellect does not move save through the medium of the particular apprehension of the sensitive part, as is said De Anima iii, 11. |
| IȘ q. 86 a. 1 ad 3 Ad tertium dicendum quod singulare non repugnat intelligibilitati inquantum est singulare, sed inquantum est materiale, quia nihil intelligitur nisi immaterialiter. Et ideo si sit aliquod singulare immateriale, sicut est intellectus, hoc non repugnat intelligibilitati. | Reply to Objection 3. The singular is incompatible with intelligibility not insofar as it is singular, but insofar as it is material, for nothing can be understood except immaterially. Therefore if there be an immaterial singular (the intellect, for example) this is not incompatible with intelligibility |
| IȘ q. 86 a. 1 ad 4 Ad quartum dicendum quod virtus superior potest illud quod potest virtus inferior, sed eminentiori modo. Unde id quod cognoscit sensus materialiter et concrete, quod est cognoscere singulare directe, hoc cognoscit intellectus immaterialiter et abstracte, quod est cognoscere universale. | Reply to Objection 4. The higher power can do what the lower power can, but in a more eminent way. Wherefore what the sense knows materially and concretely, which is to know the singular directly, the intellect knows immaterially and abstractly, which is to know the universal. |
THE LOGIC MUSEUM Copyright © E.D.Buckner 2006.