"Religion is nothing but the fantastic reflection in men's minds of those external forces which control their daily life, a reflection in which earthly forces assume the form of supernatural forces."

"The worker is the slave of capital, and the capitalist is the slave of his own capital."

"The development of large-scale industry has not only created the classes which are revolutionary, but has also created the means of their liberation."

"The world is not to be understood as a complex of ready-made things, but as a complex of processes."

"The whole of human history is a process of development from the lower to the higher, from the simple to the complex."