But I can't listen to music too often. It affects your nerves, makes you want to say stupid, nice things, and stroke the heads of people who could create such beauty while living in this vile hell.

The most important thing when ill is to never lose heart.

The soundest strategy in war is to postpone operations until the moral disintegration of the enemy renders the delivery of the mortal blow both possible and easy.

To picture world history as advancing smoothly and steadily without sometimes taking gigantic strides backward is undialectical, unscientific and theoretically wrong.

During the lifetime of great revolutionaries, the oppressing classes constantly hounded them, received their theories with the most savage malice, the most furious hatred and the most unscrupulous campaigns of lies and slander. After their death, attempts are made to convert them into harmless icons, to canonize them, so to say, and to hallow their names to a certain extent for the “consolation” of the oppressed classes and with the object of duping the latter, while at the same time robbing the revolutionary theory of its substance, blunting its revolutionary edge and vulgarizing it.

The Jewish bourgeoisie are our enemies, not as Jews but as bourgeoisie. The Jewish worker is our brother.

The only one who doesn't make mistakes is the one who doesn't do anything.