The Most Revolutionary Philosopher Since Plato?

The answer is "No."

Peguy is not the most revolutionary philosopher since Plato.

Evidence: "It is for this reason that his stylistic response to Bergson exceeds that of the modernists: he is not interested, as with Marcel Proust or Virginia Woolf, in merely reporting the supposed “givens” of subjective consciousness and memory (which is in effect to reduce Bergsonism to phenomenology), nor in expressing pure symbolic replicas of duration that are then paradoxically timeless, as in the case of sheerly abstract art."