LECTIO NINE

             § 720. Having outlined the nature and object of the potential intellect, Aristotle now goes on to discuss some relevant difficulties; and this in two stages: first stating two problems and then, at 'Or what about the receptivity', answering them. The first of the two problems might be stated thus: if intellect is, as Anaxagoras said, something simple and impassible and removed from all else, how can it actually understand? For to understand is a kind of receiving, and every receiver, as such, would seem to be affected by an agent; and it is precisely through having something in common that two things are related as agent and patient, this mutual relationship implying a material factor in common, as is shown in Book I of the De Generatione.

             § 721. The second difficulty he states at 'Again, if it is'. This difficulty is occasioned by his earlier statement that once the mind is in act it can understand itself. Now if intellect itself is intelligible, it is so in either of two ways: either merely of itself, or by way of something else conjoined with it. If the first alternative be true, then, since the intelligible as such forms one species, and since this intelligible is an intellect, it seems to follow that other intelligibles are also intellects, and thus everything intelligible is also intelligent. Should we take the second alternative, however, it would follow that the mind was like other things that are understood in being conjoined with something which makes it intelligible,--with the result, it might seem, here also, that that which is understood is always possessed of understanding.

             § 722. Then at 'Or what about the receptivity', he removes these difficulties. As to the first, relying on his earlier analysis of passivity, he reminds us that one can speak of passivity in a general sense which is common to two different kinds of change: to the mutual alteration of things which have their material factor in common and mutually exclusive, alternating formal determinations; and also to the change which implies nothing more than a reception of forms from outside the changed thing. The mind, then, is called passive just in so far as it is in potency, somehow, to intelligible objects which are not actual in it until understood by it. It is like a sheet of paper on which no word is yet written, but many can be written. Such is the condition of the intellect as a potency, so long as it lacks actual knowledge of intelligible objects.

             § 723. This is against, not only the early natural philosophers' view that the soul knows all things because it is composed of all things, but also Plato's opinion that the human soul is by nature in possession of a universal knowledge which only its union with the body has caused it to forget. (This theory is implicit in Plato's reduction of learning to remembering.)

             § 724. After this, at 'And it is itself', he answers the second difficulty; and then, at 'The reason why there is not', a fresh objection. First, then, he says that the potential intellect is itself intelligible, not indeed immediately, but like other intelligible things, through a concept. To prove this he has recourse to the principle that the actually understood object and the actually understanding subject are one being--just as he said earlier in this book, that the actually sensed object and the actually sensing subject are one being. Now the actually understood is so in virtue of an abstraction from matter; for, as we have seen, things become objects of the understanding just in the degree that they can be separated from matter. So he says 'in things separated from the material'. So the understanding and the understood are one being, provided the latter is actually understood; and the same is true of the object and subject of sensation. Speculative knowledge and what is knowable 'in this way' (i.e. in act) are identical. Therefore the concept of the actually understood thing is also a concept of the understanding, through which the latter can understand itself. That is why all the foregoing discussion of the potential intellect has been carried on in terms of the latter's act and object. For we only know the intellect through our knowledge that we are using it.

             § 725. The reason why the potential intellect cannot be known immediately, but only through a concept, is the fact that it is potential also as an intelligible object; for, as it is proved in Book IX of the Metaphysics, intelligibility depends upon actuality. And there is a like dependence in the field of sensible realities too. In this field what is purely potential, i.e. bare matter, cannot act of itself, but only through some form conjoined with it; whereas sensible substances, being compositions of potency and act, can act, to some extent, of themselves. So, too, the potential intellect, being purely potential in the order of intelligible things, neither understands nor is understood except through its own concepts.

             § 726. But God who, among intelligible objects, is the one that is perfect actuality, and also the other immaterial substances midway between potency and act, know and are known simply of and in themselves.

             § 727. Next, at 'The reason why', he answers an objection to the above solution. For if our mind, like other things, is rendered intelligible by union with some principle of intelligibility which is not precisely itself, why should not any intelligible object be itself a subject which understands;--or, as he says, we still have to enquire into 'the reason' for 'not always understanding'. Now the reason is that in any material thing the form is not actually intelligible; it is only potentially so; and only what is actually intelligible, not the merely potentially so, is identical with intellect; so that things whose form exists in matter are not themselves possessed of an intellect with which to understand. The 'mind that understands such things' (i.e. intelligible objects) is a certain immaterial potency. The material thing is indeed intelligible but only potentially, whereas what exists in an intellect is an actually intelligible form.

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