Pessimism.

His great hopes make all the more poignant his clear-eyed picture of the gathering darkness as the Revolution turned slowly into a vast self-inflicted genocide. It was the era when, as a character in his novel Conquered City says, “We have conquered everything, and everything has slipped out of our grasp.”
Adam Rothschild, in his foreword to Victor Serge’s Memoirs of a Revolutionary

I found Victor Serge’s Memoirs of a Revolutionary by accident in December. Loved the foreword, but haven’t read the book yet.