LECTIO EIGHT

             § 700. Having reached certain conclusions about the intellect as potential with respect to intelligible objects, the Philosopher now goes on to show how it is actualised. And first he shows that it is actualised intermittently; and then, at 'Now as dimension', what is the precise object of its actualisation.

             He explains how the intellect is actualised thus. The intellectual soul is, we have said, only in potency to its ideas at first. 'But when it becomes particular objects', i.e. when the mind reaches the degree of actual apprehension of intelligibles that is found in the knowledge habitually possessed by a man of science, then it can already be called an intellect in act; and that degree is reached as soon as one is capable of producing, on one's own initiative, the intellectual activity called understanding. For the actual possession of any form is coincident with the ability to act accordingly.

             § 701. Yet though a mind is already, in a way, in act when it has intelligible notions in the manner of one who possesses a science habitually, none the less the mind then is still, in a way, in potency; though not in the same way as it was before it acquired the science, either by being taught it or by its own unaided efforts. Before it acquired the habit of a science--which is its first state of actuality -it could not actualise itself at will, it needed to be brought into act by the mind of another; but once such a habit is acquired, the intellect has the power to bring itself into action at will.

             § 702. What is said here disproves the un-aristotelian position of Avicenna touching intelligible ideas. Avicenna maintained that ideas are not retained by the potential intellect, but exist in it only so long as it is actually understanding. Whence it follows that, for this intellect to come to the act of understanding anything, it must have recourse to a separated active intellect, the source of intelligible ideas in the intellectual potency.

             § 703. But against this Aristotle is clearly saying that the manner in which the mind becomes actually possessed of ideas is that of one who, possessing a science habitually, is still in potency to a given act of understanding. Thus the mind actually understanding possesses its ideas in fullest actuality; and so long as it has the habit of a science, it possesses them in a manner half-way between mere potency and complete actuality.

             § 704. And having asserted that, once the mind has become partly actual with respect to certain ideas hitherto potentially apprehended, it is capable of understanding, whereas simply regarded in itself it lacks the capacity, because this might lead one to suppose that even as in act the mind never thinks of itself, Aristotle adds that, once in act, the mind is able to think not only of other things, but also of itself.

             § 705. Next at 'Now, as dimension is one', Aristotle elucidates the object of the intellect. To understand him here we must recall the problem stated in Book VII of the Metaphysics, namely whether the 'whatness' or quiddity or essence of a thing--whatever is signified by its definition--whether this is the same as the thing itself. And whilst Plato had separated the quiddities (called by him 'ideas' or 'species') of things from things in their singularity, Aristotle was concerned to show that quiddities are only accidentally distinct from singular things. For example, a white man and his essence are distinct just in so far as the essence of man includes only what is specifically human, whereas the thing called one white man includes something else as well.

             § 706. And the same is true of anything whose form exists in matter; there is something in it besides its specific principle. The specific nature is individualised through matter; hence the indvidualising principles and individual accidents are not included in the essence as such. That is why there can be many individuals of the same specific nature--having this nature in common, whilst they differ in virtue of their individuating principles. Hence, in all such things, the thing and its essence are not quite identical. Socrates is not his humanity. But where the form does not exist in matter, where it exists simply in itself, there can be nothing except the essence; for then the form is the entire essence. And in such cases, of course, there cannot be a number of individuals sharing the same nature; nor can the individual and its nature be distinguished.

             § 707. This also should be considered, that things existing concretely in Nature--physical things--are not alone in having their essences in matter; the same is also true of mathematical entities. For there are two kinds of matter: sensible matter, which is intrinsic to physical things and from which the mathematician abstracts; and intelligible matter, intrinsic to mathematical entities. For it is clear that, whereas quantity pertains to a substance immediately, sensible qualities, like white and black or heat and cold, presuppose quantity. Now given two things of which one is prior to the other, if you remove the second, the first remains; hence if only its sensible qualities are removed from a substance by a mental abstraction, continuous quantity still remains, in the mind, after the abstraction.

             § 708. For there are some forms which can only exist in a matter which is possessed of certain definite sensible qualities; and such are the forms of physical things; and such things therefore always involve sensible matter. But there are other forms which do not call for matter possessed of definite sensible qualities, yet do require matter existing as quantity. These are the so-called mathematical objects such as triangles, squares and the like; they are abstracted from sensible matter, but not from intelligible matter; for the mind retains the notion of a quantitative continuum after abstracting from sensible quality. Clearly then, both physical and mathematical objects have their forms in matter, and in both there is a difference between a thing and its essence; which is why in both cases many individual things are found to share the same nature: e.g. men and triangles.

             § 709. If these points are understood, the text of Aristotle should present no difficulties. For he says 'dimension and the being of dimension' differ, meaning a dimension and its essence--for by 'the being of dimension' he means its essence. So also 'water' and its 'being' are distinct; and similarly in the case of 'many other things'; i.e. in all physical and mathematical objects. Hence his choice of these two examples: for dimension is a mathematical object and water a physical one.

             § 710. But this distinction is not verified in 'all things'; for in perfectly immaterial substances the thing is identical with its essence. And as such substances are beyond the reach of the human mind, Aristotle could not assign proper names to them, as he could to physical and mathematical objects; so he describes them in terms drawn from physical objects. That is why he says that 'in certain things flesh' and 'its being' are identical. He does not mean this literally, else he would not have said 'in certain things', but would have absolutely identified flesh and its being. He means that 'in certain things', i.e. immaterial substances, the two factors which we distinguish as the concrete thing and what is predicated of it--for instance flesh and its being--are identical.

             § 711. And since diversity in objects known implies diversity in the knowing faculties, he concludes by saying that either the soul knows a thing with one faculty and its essence with another, or both with the same faculty functioning in different ways. For it is obvious that flesh can only exist in matter; its form being in a certain definite and particular sensible matter. The being, too, which has flesh is a definite sensible thing, e.g. a nose. Now this sensitive nature the soul knows through the senses; that is why he adds that it is by the sense-faculty that the soul discerns the hot and the cold and so forth, of which flesh is a certain 'ratio', i.e. proportion. For the form of flesh requires a certain definite proportion of heat and cold and so forth.

             § 712. But the 'being of flesh', i.e. its essence, must be 'discerned' by some other faculty. But the functioning of two distinct 'faculties' takes place in two ways. In one way flesh and its essence can be discerned by powers in the soul which are completely distinct; the essence discerned by the intellect, the flesh by the senses; and this happens when we know the individual in itself and the specific nature in itself. But in another way the flesh and its essence may be discerned, not by two distinct faculties, but by one faculty knowing in two distinct ways--knowing in one way flesh, in another the essence of flesh; and this happens when the knowing soul correlates the universal and the individual. For, just as it would be impossible for us (as we have seen) to distinguish sweetness from whiteness if we had not a common sense faculty which knew both at once, so also we could not make any comparison between the universal and the individual if we had not a faculty which perceived both at once. The intellect therefore knows both at once, but in different ways.

             § 713. It knows the specific nature or essence of an object by going out directly to that object; but it knows the individual thing indirectly or reflexively, by a return to the phantasms from which it abstracted what is intelligible. This Aristotle expresses by saying that the intellectual soul either knows flesh sensitively and discerns the 'being of flesh' with 'another' and 'separate' potency,--i.e. other than sensitivity, in the sense that intellect is a power distinct from the senses; or it knows flesh and the 'being of flesh' by one and the same intellectual power functioning diversely; in so far as it can 'bend back', so to say, 'upon itself'. As 'stretched out straight', and apprehending directly, it 'discerns' the 'being' or essence of flesh; but by reflection it knows the flesh itself.

             § 714. Next, at 'Again, in the abstract sphere', he applies what he had said of physical objects to mathematical objects, saying that 'in the abstract sphere', i.e. in mathematics, where we abstract from sensible matter, the straight line is like the snub-nosed in the sphere of sensible matter. For line is a mathematical object, as a snub-nose is a physical one; and line essentially involves a continuum, as what is snub-nosed a nose. But the continuum is intelligible matter, as what is snub-nosed is sensible matter. Therefore in mathematics also the thing and its essence, e.g. the straight line and its straightness, are different; hence too, even in mathematics, things and essences must be objects of different kinds of knowing.

             § 715. As an instance of this let us suppose for a moment, with Plato, that the essence of straight line is duality (for Plato identified the essences of mathematical objects with numbers, so that a line was unity, a straight line duality, and so on). The soul then must know mathematical objects and their essences in different ways. Hence, just as it can be shown, in the case of physical objects, that the intellect knowing their essences is other than the senses which know them in their individuality, so too, in the case of mathematics, it can be shown that what knows the essences, i.e. the intellect, is distinct from what apprehends mathematical objects themselves, i.e. the imagination.

             § 716. And lest it be said that the mind works in the same way in mathematics and in natural science, he adds that the relation of things to the intellect corresponds to their separability from matter. What is separate in being from sensible matter can be discerned only by the intellect. What is not separate from sensible matter in being, but only in thought, can be perceived in abstraction from sensible matter, but not from intelligible matter. Physical objects, however, though they are intellectually discerned in abstraction from individual matter, cannot be completely abstracted from sensible matter; for 'man' is understood as including flesh and bones; though in abstraction from this flesh and these bones. But the singular individual is not directly known by the intellect, but by the senses or imagination.

             § 717. From this text of Aristotle one can go on to show that the intellect's proper object is indeed the essence of things; but not the essence by itself, in separation from things, as the Platonists thought. Hence this 'proper object' of our intellect is not, as the Platonists held, something existing outside sensible things; it is something intrinsic to sensible things; and this, even though the mode in which essences are grasped by the mind differs from their mode of existence in sensible things; for the mind discerns them apart from the individuating conditions which belong to them in the order of sensible reality. Nor need this involve the mind in any falsehood; for there is no reason why, of two conjoined things, it should not discern one without discerning the other; just as sight perceives colour without perceiving odour, though not without perceiving colour's necessary ground which is spatial magnitude. In like manner, the intellect can perceive a form apart from its individuating principles, though not apart from the matter required by the nature of the form in question; thus it cannot understand the snub-nosed without thinking of nose, but it can understand a curve without thinking of nose. And it was just because the Platonists failed to draw this distinction that they thought that mathematical objects and the essences of things were as separate from matter in reality as they are in the mind.

             § 718. Furthermore, it is clear that the intelligible ideas by which the potential intellect is actualised are not in themselves the intellect's object: for they are not that which, but that by which it understands. For, as with sight the image in the eye is not what is seen, but what gives rise to the act of sight (for what is seen is colour which exists in an exterior body), so also what the intellect understands is the essence existing in things; it is not its own intelligible idea, except in so far as the intellect reflects upon itself. Because, obviously, it is what the mind understands that makes up the subject-matter of the sciences; and all these, apart from rational science, have realities for their subject-matter, not ideas. Clearly then, the intellect's object is not the intelligible idea, but the essence of intelligible realities.

             § 719. From which we can infer the futility of an argument used by some to prove that all men have only one potential intellect in common. They argue from the fact that all men can understand one and the same object; and say that if there were really many human intellects they would necessarily have many intelligible ideas. But these intelligible ideas are not precisely what the mind understands; they are only the latter's likeness present in the soul; hence it is quite possible for many intellects to possess likenesses of one and the same object, so that one thing is understood by all. Besides, the separated substances must know the essences of the physical things which we know; and clearly their intellects are distinct. Hence, if the above argument were valid, its conclusion--that all men have only one intellect--would still involve a difficulty; for one cannot reduce all intellects to one.

429b 23-430a 9

PROBLEMS ARISING

INTELLECT AS INTELLIGIBLE

             ONE MIGHT WELL ENQUIRE (IF THE INTELLECT IS simple and impassible, having nothing in common with anything else, as Anaxagoras said) how it understands, if understanding is a receiving. For it seems that one thing acts and another is acted on, only in so far as there is a factor common to the two.§ 720

             Again, if it is itself an intelligible: then either there is intellect in other intelligible things--(unless it is intelligible by virtue of some extrinsic principle) the intelligible being specifically one; or it will have, mixed with itself, something that makes it intelligible, as other things have.§§ 721-2

             Or what about the receptivity in a general sense, already alluded to in making distinctions on this point? Before it makes an act of understanding, the intellect is its intelligible objects potentially, but not actually. It must be as with a tablet on which there is nothing actually written; and so indeed it is in the case of intellect.§§ 722-3

             And it is itself an intelligible like other intelligible objects. For in things separated from the material, intellect and what is understood by it are identical. Speculative knowledge is the same as what is knowable in this way. §§ 724-6

             The reason why there is not always understanding must be considered. In material things, each intelligible object exists only potentially. Hence in them is no intellect, for the mind that understands such things is an immaterial potency. The intelligible exists, however [in them]. § 727