In Good Without God: What a Billion Nonreligious People Do Believe, Greg Epstein (2007) offered Darwin, Marx, Nietzsche and Freud as the "Four Horsemen of the Apocalypse" of their time. Massimo Pigliucci characterized the Pre-Socratics as a "intellectually wild" bunch in his (2010) book Nonsense on Stilts: How to Tell Science from Bunk. Did the Pre-Socratics have their own "Four Horsemen"?
As it happens, there are also four core arguments against God's existence that have persisted since ancient times. Using these four arguments as an organizing principle, I present for your consideration the Four Horsemen and their Pre-Socratic analogues.
The argument from inconsistent revelations- All religions can't be right, so they're probably all wrong. Jennifer Michael Hecht calls this cosmopolitan doubt. Xenophanes reasoned that the gods were narcissistic fantasies.
The argument from evil. There is no divine will dispensing reward and punishment. Heraclitus conceived of a self-generated, mechanistic universe.
Lack of empirical evidence- Discovery trumps revelation. For Anaxagoras, everything had a natural explanation.