Marxism is the science of the laws governing the development of nature and society, the science of the revolution of the oppressed and exploited masses, the science of the victory of socialism in all countries, the science of building communist society.

Nature never breaks her own laws.

If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin.

All bodies together, and each by itself, give off to the surrounding air an infinite number of images which are all-pervading and each complete, each conveying the nature, colour and form of the body which produces it.

Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.

But while they prate of economic laws, men and women are starving. We must lay hold of the fact that economic laws are not made by nature. They are made by human beings.