(But this it is perhaps worth while to inquire, how the cyclic substance(814) can contain the incorporeal causes of the forms that are embodied in matter. For that, apart from these causes, it is not possible for generation to take place is, I think, clear and manifest. For why are there so many kinds of generated things? Whence arise masculine and feminine? Whence the distinguishing characteristics of things according to their species in well‐defined types, if there are not pre‐existing and pre‐established concepts, and causes which existed beforehand to serve as a pattern?(815) And if we discern these causes but dimly, let us still further purify the eyes of the soul. And the right kind of purification is to turn our gaze inwards and to observe how the soul and embodied Mind are a sort of mould(816) and likeness of the forms that are embodied in matter. For in the case of the corporeal, or of things that though incorporeal come into being and are to be studied in connection with the corporeal, there is no single thing whose mental image the mind cannot grasp independently of the corporeal. But this it could not have done if it did not possess something naturally akin to the incorporeal forms. Indeed it is for this reason that Aristotle himself called the soul the “place of the forms,”(817) only he said that the forms are there not actually but potentially. Now a soul of this sort, that is allied with matter, must needs possess these forms potentially only, but a soul that should be independent and unmixed in this way we must believe would contain all the concepts, not potentially but actually. Let us make this clearer by means of the example which Plato himself employed in the Sophist, with reference certainly to another theory, but still he did employ it. And I bring forward the illustration, not to prove my argument; for one must not try to grasp it by demonstration, but only by apprehension. For it deals with the first causes, or at least those that rank with the first, if indeed, as it is right to believe, we must regard Attis also as a god. What then, and of what sort is this illustration? Plato says that, if any man whose profession is imitation desire to imitate in such a way that the original is exactly reproduced, this method of imitation is troublesome and difficult, and, by Zeus, borders on the impossible; but pleasant and easy and quite possible is the method which only seems to imitate real things. For instance, when we take up a mirror and turn it round we easily get an impression of all objects, and show the general outline of every single thing. From this example let us go back to the analogy I spoke of, and let the mirror stand for what Aristotle calls the “place of the forms” potentially.)