“ It was our friends who created the theory of ideas. But we must follow the view that saving the truth requires sacrificing our preferences, especially since we too are philosophers. You can love friends and the truth; but the honest thing is to give preference to the truth.” Ethics to Nicomachus .
For Aristotle, the theory of ideas starts from the Socratic search to define the essence of things, especially virtues. In defining an essence, it contains the general or universal concept of it, but while Socrates did not grant a separate existence to the universals and definitions, the Platonics granted them the status of “Ideas” by admitting as such everything that is universally affirmed. Aristotle cannot admit the separate character of essences: if Ideas are essences that exist separately from things, then they are substances, this is subsistent realities, as long as they possess independent existence.
Aristotle says that trying to explain this world, Plato duplicates it, thus doubling the difficulties: now we have to explain two worlds.
If the essences of things are separated from these, then they are not properly their essences.
Although Plato claimed that Ideas were “causes” of things by pretending to explain the origin with this, it is evident to Aristotle that they can never be a “cause of movement.” To solve this problem Plato had to introduce the mythical figure of Demiurge.
Aristotle said to resort to mathematics was not the way to correct the shortcomings of the theory of Ideas. On the contrary, the mathematization of theory transformed Platonism into Pythagorism.
Aristotle does not reject the whole theory of Ideas, but the separate existence of Ideas. Moreover, it will be faithful to the line initiated by Socrates and Plato: true science is that which focuses on the general and the universal: the search for the common essence, which for Aristotle, is found in things themselves and not separated from them.
