As discussed in Chapter 1, the Pre-Socratics were preoccupied with resolving an issue first formulated by Thales of Miletus (580 BC): the Problem of the One and the Many--i.e., the challenge of identifying an ultimate reality (the One) underlying all existing things (the Many). This problem presupposes monism, an ontological belief that ultimate reality is, in some sense, one unified thing or substance.

A more contemporary philosopher, Martin Heidegger, famously said that the most fundamental ontological question is this: "why is there something rather than nothing?" In other words, why does anything exist in the first place? Do you believe that, in answering the Problem of the One and the Many, the Pre-Socratics also addressed Heidegger's question, or did they merely sidestep it?