"If you want to be consistent in your aesthetic criticism, then forbid also a too serious and too modest investigation of the truth, for too great seriousness is the most ludicrous thing of all, and to…"

"The worker is the owner of his labour power, but he cannot sell it without selling himself."

"Revolutions are the locomotives of history."

"The ideas of the ruling class are in every epoch the ruling ideas, i.e. the class which is the ruling material force of society, is at the same time its ruling intellectual force."

"The meaning of history is the progress of humanity toward freedom and self-consciousness."