Many aspects of Parmenides’s thought remain puzzling even when we have collected all the scraps of evidence from his own writings and those of later … - Catherine Rowett

Often, when thinking about Socrates (or about Plato’s depiction of Socrates), we need to remember that he is reacting to the Presocratics, but the reverse is never true.

Whether or not Zeno was merely trying to defend Parmenides from the ridicule of others, there is no doubt that he has pushed the analysis of reality onto a new plane. He makes us think not just about objects in space, but about space as a structure within which they exist; about motion not just as the behaviour of physical bodies, but as a theoretical concept involving conceptual divisions in space and time; about number not just as a way of counting finite bodies but as a rational system potentially (or actually) continuing ad infinitum, with the problematic consequences that that might entail; about the notions of ‘before’ and ‘after’ in time, and how long the duration of the present is.

For Heraclitus, the logos is something that we need to learn to notice if we are to understand the true significance of the world. It manifests itself all around us but, Heraclitus suggests, only a few intelligent people ever realize what is going on.