Plato as proto-Hegelian? Troubling Play (SUNY Press, 2005)

Plato's Parmenides shows that very general oppositions transcend definition precisely because they are fundamental to the process of discursive definition itself. The troubling play Parmenides demonstrates for Socrates indicates that these pairs of opposed archai (beginnings, origins) are signposts of the bounds of being. But an archē may not be thought: the fundamental oppositionality with which thought begins may be given various names, but each of these singular terms is defined (ambiguously) in opposition to its other, by way of differences of function within an ideal nexus.

Moreover, the ideal matrices themselves share in this indefinable heterogeneity. The form has singular meaning in dialectical differentiation from more fundamental archai oppositions, in differentiation from other forms, and by contrast with its own various instantiations; for the disclosure of any particular meaning occurs only within the context of human orientations toward entities in the world. The upshot is that a complete matrix of ideas--an ideal whole--cannot be thought, not even by a god. Furthermore, we do not know the archai, but live them; we cannot think fundamental oppositionality, but we cannot think without it.
--Troubling Play: Meaning and Entity in Plato's Parmenides, p. 7