Ideology
Orwell's ultimate object of derision in Homage to Catalonia is the dogma of unbending ideology. For systems intended to unite and liberate, Orwell saw only the total failure of Anarchism, Communism, Socialism, and Marxism to unify people in the Spanish Civil War. As Orwell states, the Spanish Leftists were destroyed by a “plague of letters” due to ideological squabbling. The liberation of the worker was a failure because the war effort could not decide what or who to liberate. An idealized form of ideological system failed as it could not perpetuate or save itself. The Nationalists cause was simply more unified in objective. All the Spanish leftist organizations failed to protect the liberty they promised.
Warfare
Homage to Catalonia identifies the idealized/romantic version of warfare as ultimately a farce. Orwell came to Spain believing he would help fight Fascists, but only ever got into a gunfight with one and was shot by another. Each experience he states was only a little odd and not very remarkable. The actual war was incredibly boring and monotonous to Orwell. Long periods of nothing were only punctuated by the disorder of the Spanish forces. The entire war was largely fought by sitting in cold, rainy trenches.
Propaganda
Posters plastered up by the many vying ideological factions were a common sight all across Catalonia. A sight which Orwell regards as slightly humorous as the war effort begins to fail. The bright posters calling for the liberation of workers create a sort of dissonance as the soldiers/volunteers become more and more miserable. As the war turns against the Spanish Leftists, the actual purpose of ideology becomes second to the war and survival. The decay of the posters (and their meanings) match the decay of the people
Journalism
Near the end of the book, Orwell reflects on the Spanish Civil War as a historical event. A war he believes will be impossible to describe in retrospect due to the failure of the press. Reporting on the Spanish Civil War itself became another arena of contesting ideologies. The reporting upon the war became another dispute between Republicans and Nationalists, Leftists and Conservatives, Communist and Capitalists. As another reporter, Orwell hoped to write a history of the even as one who participated in it, but eventually accepts this is impossible too. He can only be another voice (with his own bias) among the sea of propaganda pertaining to the war.
Spain
Orwell's conclusion about the war is how little it actually changed Spain as a whole. Despite being so devastating, the old Spain is still visible below the destruction. The Spanish soldiers and volunteers still hold to their old habits, Spanish society continues on as normal beyond the battlefield, and there are plenty of towns totally unaffected by the conflict. It is only as he is leaving (or more fleeing) Spain when Orwell can see the warm, Mediterranean Spain of fantasy. Though war is often seen as the most extreme circumstance in human society, it has done little to actually change Spanish society at its core.
