soul is ratiocinative and conceives opinions-the passage is not less tautologous in the original—and in another passage he speaks of it as the part by which the mind knows and understands'. Aristotle accordingly regards reason as in many ways the direct antithesis of sense. The old psychologists were much mistaken when they viewed perception as identical with thought and explained thought itself as a material process2. The very possibility of error on the part of thought shews it to be something which must be distinguished from the communications of the special senses: they, as we have seen before, are as such always true. Sense again requires to go outside itself to find its object: reason finds its object as it were within and thus is free to act according to our will. For sense is limited to the particular and individual: reason deals rather with the universal and the abstract3.

Sense and reason are in fact related to one another just as are the concrete and the abstract, the immediate phenomenon and its essential nature. Some things indeed are so abstract to begin with that we cannot make the separation-mind and the being or abstract idea of mind are identical-but in the majority of substances we can draw the distinction-distinguish for example between water and the idea of water, flesh and the idea of flesh. Sense then, we may say, enables us to know the concrete thing, the particular qualities of heat or cold; whereas thought relates to the abstract nature, the real idea of such objects*.

Between these two applications of our cognitive capacities Aristotle does not, however, draw immediately any hard line of division. Between the individual and the universal, the

1 429 23, λέγω δὲ νοῦν ᾧ διανοεῖται καὶ ὑπολαμβάνει ἡ ψυχή. 41910, ᾧ γινώσκει τε ἡ ψυχὴ καὶ φρονεῖ.

2 III. 3, 427*26.

3 11. 5, 417822, αἴτιον δ ̓ ὅτι τῶν καθ ̓ ἕκαστον ἡ κατ' ἐνέργειαν αἴσθησις, ἡ δ ̓ ἐπιστήμη τῶν καθόλου· ταῦτα δ ̓ ἐν αὐτῇ πώς ἐστι τῇ ψυχῇ. διὸ νοῆσαι μὲν ἐπ ̓ αὐτῷ, ὁπόταν βούληται, αἰσθάνεσθαι δ ̓ οὐκ ἐπ' αὐτῷ· ἀναγκαῖον γὰρ ὑπάρχειν τὸ αἰσθητόν.

• III. 4, 429310.

concrete and the abstract, there is not so great an interval as Plato had supposed. Clearly then the faculties which apprehend these two aspects of phenomena cannot be sharply marked off from one another. They are in fact, Aristotle thinks, not so much different faculties as different applications of the same faculty, and he accordingly compares them to the same line as it is now straightened now bent back upon itself. The cognition of the senses resembles the straight line-sense that is to say knows its object directly and immediately. The cognition. of reason resembles rather the bent line which returns upon itself that is to say, reason in becoming conscious of the essential ideas of phenomena is but as it were finding itself in things, and the mind after perceiving from reason the idea which explains the phenomenon, brings it back again to reason as its home. But it is the same line which is now bent now straight: it is only a difference of aspect which subsists between the cognition of sense and that of thought'. The difference indeed is not much greater than that which we might try to draw between the knowledge of an abstract idea and that of the idea of the same. idea. Just in fact as it is only a different aspect of the reason which considers now the straight line now the idea of the straight line: so with regard to sense and thought we must remember that it is one and the same object of which sense comprehends the concrete, thought the immaterial aspect, and that the distinction in the faculties is no greater than that which subsists between the aspects of the object".

Not only however does Aristotle thus coordinate in some respects the cognition of the senses with the cognition of the

1 429 15, τῷ μὲν οὖν αἰσθητικῷ τὸ θερμὸν καὶ τὸ ψυχρὸν κρίνει καὶ ὧν λόγος τις ἡ σάρξ· ἄλλῳ δὲ ἤτοι χωριστῷ ἢ ὡς ἡ κεκλασμένη ἔχει πρὸς αὐτὴν ὅταν ἐκταθῇ τὸ σαρκὶ είναι κρίνει. Neuhauser makes νοῦς the nominative to κρίνει. But though grammatically this seems the easier interpretation, a more general subject seems required. Teichmüller's view (Studien p. 494) that the crooked line is that in which sensuous images are gathered together by thought into a concept, the straight line that in which they are scattered and isolated as merely individual, is ingenious but scarcely more. See my note on the passage itself.

2 111. 4, 42021, καὶ ὅλως ἄρα ὡς χωριστὰ τὰ πράγματα τῆς ὕλης, οὕτω καὶ τὰ περὶ Tov vouv. Cp. De Sensu, c. 7, 449*15.

reason: sense further serves to explain the mode in which reason operates. The same formula of assimilation, of suffering, and receiving, which served for our nutritive and sensitive capacities, is thought also adapted to explain our higher intellectual functions. Reason is affected by or suffers from its object (máoxe), just as sense, we saw, received impressions from the qualities of outward things. But if even sense was not a merely passive state, if even there an innate power was presupposed, enabling it to separate the form from the matter and grasp its objects in their formal aspects, still more must this be the case with the exercise of thought. And accordingly Aristotle no sooner suggests that reason may be like sense and therefore be affected by its object than he adds it must be therefore unaffected-it must, that is to say, in order that it may receive its object, be its superior rather than its subject'. He accepts then so far the expression of Anaxagoras that reason is something unblended with material objects, something which remains untrammelled by the outward world and which can therefore master it by knowing it.

Anaxagoras' expression however suggests to Aristotle's mind a difficulty whose solution enables him to explain still more clearly the place of reason in the economy of knowledge. If thought be something apart from things, something outside the world, how is knowledge ever to be attained (ei ó voûs μndevì μηθὲν ἔχει κοινόν, πῶς νοήσει)? Thought, it has been said, is a kind of receptivity. But if one thing is to be acted on, another to act upon it, there must be some common element or factor to combine them (ᾗ γὰρ τι κοινὸν ἀμφοῖν ὑπάρχει τὸ μὲν ποιεῖν δοκεῖ τὸ δὲ πάσχειν). Some light is thrown upon the problem

1 42913, εἰ δή ἐστι τὸ νοεῖν ὥσπερ τὸ αἰσθάνεσθαι, ἢ πάσχειν τι ἂν εἴη ὑπὸ τοῦ νοητοῦ ἤ τι τοιοῦτον ἕτερον· ἀπαθὲς ἄρα δεῖ εἶναι, δεκτικὸν δὲ τοῦ εἴδους καὶ δυνάμει τοιοῦτον ἀλλὰ μὴ τοῦτο. Themistius would seem to have read ἑτέρων ἀπαθές, but the correctness of the ordinary text is confirmed by line 29, οὐχ ὁμοία ἡ ἀπάθεια τοῦ αἰσθητικοῦ καὶ τοῦ νοητικοῦ.

2

42918, ἀνάγκη ἄρα, ἐπεὶ πάντα νοεῖ, ἀμιγῆ εἶναι, ὥσπερ φησὶν ̓Αναξαγόρας, ἵνα κρατῇ, τοῦτο δ' ἐστὶν ἵνα γνωρίζῃ· παρεμφαινόμενον γὰρ κωλύει τὸ ἀλλότριον καὶ ἀντιφράττει.

by the further problem, how reason itself can become the object of thought. If, argues Aristotle, thought or reason is an object of thought just because it is thought (εἰ μὴ κατ ̓ ἄλλο (νοῦς) avròs vonτós), then, on the supposition that everything becomes thinkable and knowable in the same way (êv dè Tò vontòv eïdei) we must assume that other things require (in order to be thought and known) to be endowed with reason; or, if reason be not an object of thought just because it is reason, we must suppose that reason, instead of being free from admixture, has some element incorporated with it which makes it thinkable in the same way as other external things are (ή γὰρ τοῖς ἄλλοις ὁ νοῦς ὑπάρξει, ἢ μεμιγμένον τι ἕξει ὅ ποιεῖ νοητὸν αὐτὸν ὥσπερ τἆλλα). But both these alternatives are eventually rejected: we must neither reduce things to thought nor thought to things, neither spiritualize matter nor materialize spirit. Rather we must allow the presence of a common factor between subject and object in the processes of thought (ἢ τὸ μὲν πάσχειν κατὰ κοινόν τι). And by virtue of this community reason may be said to hold in itself implicitly the whole world of experience (δυνάμει πώς ἐστι τὰ vonτà ô voûs)—thought, that is to say, is not only within us but without us-and the world of reason outside us is present potentially in the world of thought within-the microcosm contains implicitly the macrocosm. But this subjective world of thought is to begin with a mere à priori possibility: it is a mere form. without the actual experience which will give these forms reality (ἀλλ ̓ ἐντελεχείᾳ οὐδὲν πρὶν ἂν νοῇ). And thus the relation of thought to the world is not unlike that of a writing tablet to the knowledge which will be graven on it'. The metaphor is not to be pressed as though it implied a purely empirical account of thought and knowledge. The comparison refers simply to one point, and it is misused when taken as equivalent to Locke's white paper or other sensualist similes. All that Aristotle means to bring out by his comparison is that just as a sheet of

1 4301, δεῖ δ ̓ οὕτως ὥσπερ ἐν γραμματείῳ ᾧ μηδὲν ὑπάρχει ἐντελεχείᾳ γεγραμμένον· ὅπερ συμβαίνει ἐπὶ τοῦ νοῦ.

paper may be regarded as containing a priori and implicitly all that will be written on it, so similarly the intellect or reason may be viewed as implicitly containing its objects, which like itself are rational.

To the question then, How is knowledge possible? How do we think things? Aristotle answers that we do so only in so far as the object of our experience is also reasonable. And this he makes still clearer by distinguishing between the two kinds of objects of thought to which reason may apply itself. These are either abstract and immaterial or concrete and material. In the former case this correspondence between our thought and the thought of things is of course complete: "in the case of immaterial conceptions the subject and the object of thought are identical” (ἐπὶ τῶν ἄνευ ὕλης τὸ αὐτό ἐστι τὸ νοοῦν καὶ τὸ Voovμevov). But in material objects this correspondence is of course not so directly present. How then do they come to be objects of thought-how in fact are they known? The answer is that, though not explicitly rational, they are still so implicitly -that is, they presuppose a basis of thought-so that even in dealing with material objects our thought is simply refinding itself in the world.

Thus far then Aristotle's position would seem to be that thought and knowledge presuppose a universe already thought as an intelligible world. But the question now arises-What is this object of thought? How do we get to something intelligible? Reason, we may grant, is the faculty of receiving and applying ideas, of acquiring a knowledge of the general character of things, of filling up the as yet unwritten book of our experience. But there is a problem to be solved before this work of reason is possible: we must have secured our object of thought, our intelligible world, our matter on which thought is to operate-we must have found the instrument by which thought can exercise its actual functions. To do so we must advance a step farther than Aristotle's analysis has yet carried us. We must see that reason does not only receive ideas and in the course of its experience