argument with one of my professors in grad school, who asserted that atheism did not exist before the late 18th century because "people during that period were incapable of perceiving the world without the presence of god".

He continued to assert this despite evidence - like Meslier - to the contrary. I found it very difficult to take him seriously as a scholar after that.

It's right there in the records, teaching atheism to students.

"To him, religions were fabrications fostered by ruling elites; although the earliest Christians had been exemplary in sharing their goods, Christianity had long since degenerated into encouraging the acceptance of suffering and submission to tyranny as practised by the kings of France: injustice was explained away as being the will of an all-wise Being."