A man cannot become a child again, or he becomes childish.

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.

While the miser is merely a capitalist gone mad, the capitalist is a rational miser.

Money degrades all the gods of man and converts them into commodities.

Only in community with others has each individual the means of cultivating his gifts in all directions; only in the community, therefore, is personal freedom possible.

Once the inner connection is grasped, all theoretical belief in the permanent necessity of existing conditions collapses before their collapse in practice -- Letter to Ludwig Kugelmann (July 11, 1868)

Religious distress is at the same time the expression of the real distress and also the protest against real distress. Religion is the sigh of the oppressed creature, the heart of a heartless world, just as it is the spirit of the spiritless condition. It is the opium of the people.