In Battling the Gods: Atheism in the Ancient World, Tim Whitmarsh examines the evidence that there were ancient Greeks and Romans who denied the existence of the gods and professed their nonbelief to others, even if they did so cautiously. Richard F. Thomas calls the book “stimulating and learned,” and praises its combination of scholarly seriousness with lucid writing, but ultimately concludes that its author is looking for something that isn’t there:
Not everyone will go along with [Whitmarsh’s] conclusion . . . that “[b]y the 2nd century CE, atheism in the full, modern sense had acquired full legitimacy as a philosophical idea.” [Much more convincing is the scholar Jan Bremmer’s opinion] “that in historical reality no practicing atheists are mentioned in our sources for [this] period. In the first two centuries of our era, atheism had mainly become a label to be used against philosophical opponents but not to be taken too seriously.” . . .
Pre-Socratic [philosophers] or sophists could be labeled atheist, comic playwrights called philosophers atheists, the character Sisyphus could utter atheist doctrine on stage (but we know where he ended up), Stoics called Epicureans atheists, and in due course pagans would call Christians atheists (no temples or statues). . . . That is, charges of atheism, whether in the law courts or the comic poets, cannot easily be taken, in the absence of other evidence, to indicate the widespread practice of atheism—whatever that would have looked like. . . .
Whitmarsh seems to want his Greeks to be more modern, more fully rational and materialist, competing in their atheism with modern atheists. He is driven by a desire to push back against the “modernist mythology” that atheism is an invention of the European Enlightenment. But, again, it is generally accepted that atheist doctrine was a topic of ancient philosophical debate. Where there is doubt [is about whether there were actual avowed atheists] beyond that debate. In the introduction he proposes an “archaeology of religious skepticism . . . in part an attempt to excavate ancient atheism from underneath the rubble heaped on it by millennia of Christian opprobrium.” It is, however, in the pre-Christian evidence, from Plato to [the 2nd-century CE philosopher] Sextus Empiricus, that there is such paucity of evidence. He is therefore driven to see atheism as more widespread than the evidence will support.