Atoms, Void, and Nothing Else

Democritus proposed the earliest fully worked out materialist cosmology: everything that exists is composed of indivisible atoms moving through empty void, differing from one another only in shape, arrangement, and position, with even thought and sensation explained as the physical collision of finer, smoother atoms making up the soul. Epicurus took over this atomism and pushed its implications further, arguing that since everything happens through the collision and combination of atoms according to fixed patterns, there is no room for divine intervention, and the gods, if they exist at all, live remote, untroubled lives with no interest in human affairs. This was materialism doing real theological work rather than remaining a neutral physics: for Epicurus, freeing people from fear of divine punishment and an afterlife of torment was the entire point of getting the physics right.

The position's most persistent difficulty, then as now, is explaining consciousness itself: it is one thing to say that lightning is really just electrical discharge, and another to say that the felt quality of pain or the color red is really just neurons firing, since no description of atoms in motion obviously entails what it is like to experience anything at all.