This is one of my favorite movies, but the post above is well said and I don't have much to add. What always strikes me about it is how well it zeroes in on the issue of the faceless institution vs. the individual. Mireau will do anything to secure his place in the institution (the army) and has no problem shutting out human decency. The palatial chateaux where the higher-ups spend the war not only show the gulf between them and the fighting man, but emphasize the weight of the massive, cold, unassailable institution. ETA: David Simon of The Wire
has said Paths of Glory
was a big inspiration for him, and you can see how. If you like this movie, BTW, another outstanding wartime courtroom movie that has some similar themes is the Australian Breaker Morant
Douglas is great, he really makes you believe his heart is in it. George Macready's specialty was cold heavies, and this is one of the coldest. Meeker, Carey and Turkel were good as mentioned above, I would also point out Wayne Morris, who plays the drunken and dishonest Lt. Roget, was actually a decorated navy fighter pilot in WW2.
Some people say Kubrick is a cold, unfeeling technical filmmaker, but the last few minutes of Paths of Glory
are quite remarkably moving, all the more so from how simply it is approached.