Ideenlehre
The most famous criticism of the Theory of Forms is the Third Man Argument by Aristotle in the "Metaphysics". Plato had actually already considered this objection with the idea of "large" rather than "man" in the dialogue "Parmenides", using the elderly Elean philosophers Parmenides and Zeno characters anachronistically to criticize the character of the younger Socrates who proposed the idea. The dialogue ends in "aporia".