Religion is the opium of the masses.

The world will be for the common people, and the sounds of Happiness will reach even the deepest springs.

In proportion therefore, as the repulsiveness of the work increases, the wage decreases.

Since only what is material is perceptible, knowable, nothing is known of the existence of God.

Take away a nation's heritage and they are more easily persuaded.

Natural science will in time incorporate into itself the science of man, just as the science of man will incorporate into itself natural science: there will be one science.

Mankind always sets itself only such tasks as it can solve; since, looking at the matter more closely, we will always find that the task itself arises only when the material conditions necessary for its solution already exist or are at least in the process of formation.