From George Orwell's Homage to Catalonia, a non-fiction book that describes how he went to Spain to journal the Spanish Civil War and ended up joining the Anarchist POUM to fight Franco and the Fascists. This is a fascinating book, and not just because it has one of the best scenes of a running street gun-battle I've ever read.
"The Communist's emphasis is always on centralism and efficiency, the Anarchist's on liberty and equality." - George Orwell, from Homage to Catalonia.
"Perhaps when the next great war comes we may see that sight unprecedented in all history: a jingo with a bullet hole in him."
"A fat man eating quails while children beg in the street for bread is a disgusting sight, but you are far less likely to see it when you are within sound of the guns."
"I have no particular love for the idealized "worker" as he appears in the Communist's mind, but when I see an actual flesh-and-blood worker in conflict with his natural enemy, the policeman, I do not have to ask myself which side I am on."