 The passage in the Euthyphro where Socrates asks Euthyphro to identify the one feature that is common to all that is holy or pious makes intelligible, however, the reason why Plato felt encouraged to develop the idea of transcendent Forms in dialogues that no longer confine themselves to the ‘negative’ approach of questioning the foundations or premises of other people’s convictions. The requisite unity and invariance of entities such as ‘the holy’, ‘ the beautiful’, ‘the just’ or ‘the equal’, necessarily prompts reflections on their ontological status and on the appropriate means of access to them. Given that they are the objects of definition and the models of their ordinary representatives, there is every reason not only to treat them as real, but also to assign to them a state of higher perfection. And once this step has been taken, it is only natural to make certain epistemological adjustments. For, access to paradigmatic entities is not to be expected through ordinary experience, but presupposes some special kind of intellectual insight. It seems, then, that once Plato had accepted invariant and unitary objects of thought as the objects of definition, he was predestined to follow the path that let him adopt a metaphysics and epistemology of transcendent Forms. The alternative of treating these objects as mere constructs of the mind that more or less fit the manifold of everyday experience, clearly was not to Plato’s taste. It would have meant the renunciation of the claim to unassailable knowledge and truth in favor of belief, conjecture, and, horribile dictu, of human convention. The very fact that mathematics was already an established science with rigorous standards and unitary and invariant objects must have greatly enhanced Plato’s confidence in applying the same standards to moral philosophy. It led him to search for models of morality beyond the limits of everyday experience. This, in turn, explains the development of his theory of recollection and the postulate of transcendent immaterial objects as the basis of reality and thought that he refers to in the Meno, and that he presents more fully in the Phaedo.