Neither the French Revolution, nor Hitler, nor Stalin had ANYTHING to do with Atheism.
did not hear the French, nor the Germans nor Russians proclaiming "I
condemn you to death in the name of nothing in particular."
Again, no one ever killed anyone because they were being too reasonable.
The above is most of a comment from some guy on Daylight Atheism in response to your standard atheism-is-Stalinism troll, and I was agreeing with it until I got to the last line and thought: is that really true? Nobody's ever killed anybody from being too reasonable? Now what the commenter means by 'reasonable' is no doubt some general term of approbation, but in the sense of 'guided by reason', plenty of people have had good reasons to kill. In the strictly amoral sense, there are plenty of reasons for a predator to murder if he thinks he can get away with it. Even if we assume that 'reasonable' includes some kind of 'moral reason' a la bastardized Kant, there have still been plenty of people who murdered for what they thought were good moral reasons.
It would probably do this commenter good - say I, from atop my mighty throne - to read some Koestler. Darkness at Noon's magnificent Rubashov (and his friend and jailer, Ivanov), outlines the utilitarian logic behind the horrors of Stalin's Russia. Friends must be sacrificed, they say, to achieve a better world; and the genius of Koestler is that we can read of Little Loewy hanging himself or Arlova being executed without immediately wanting to strangle Rubashov. The mad policies of Stalin, on close examination, are powerfully rational, and it's our own blind spots that cause us to recoil from them.
Maybe I'm being uncharitable; maybe 'reasonable' doesn't strictly mean 'rational'. Still, 'reasonable' people are prone to a kind of utilitarian logic that can have some very dangerous conclusions. While atheism by itself doesn't lead to utilitarian atrocities - and of course utilitarianism doesn't equate to Stalinism - those advocating reason as a panacea need to embrace humility in the kind of conclusions they draw.