While Plato used as base of its philosophical doctrine only the reason, Aristotle also used the directions. Aristotle was therefore an empiricist, that is, that one that defends the theory of that all the knowledge of the world comes of what it says its directions to them. 3.1 The ideas are not innate. ' ' The doubt begins is it of sabedoria.' ' Aristotle In its perpetual search for and the invariant one, Plato arrived at the theory of the perfect ideas, that are above of the sensorial world. Moreover, Plato considered these more real ideas of what the proper phenomena of the nature. First it came the idea hen and later all the hens of the world of the directions, ciscando with its projected shades on the wall of a cave. Aristotle found that Plato had turned all upside-down one.

It agreed to its master where an isolated unit of the hen passes, that no hen lives forever. It also agreed that, in itself, the form of the hen was perpetual and invariant. But ' ' ideia' ' hen did not pass to it of a concept created by the men and to the men, after them having seen certain number of hens. ' ' ideia' ' or it forms hen did not exist, therefore, before the lived experience. For Aristotle ' ' forma' ' hen consists of the characteristics of the hen, that is, in what we call species.

Aristotle said that the forms they were inside of the proper things, thus the hen in itself and the form hen are two so non-separable things how much to the body and the soul. The presented one above was a drastic rupture with the platonic thought, while Plato judged that the reality maximum is in thinking with the reason, Aristotle was to perceive with the directions. According to Aristotle, what human being existed in the soul, nothing more age of what reflected of objects of the nature, the opposite to the thought of Plato.