“Revolutions are the locomotives of history.”

The only antidote to mental suffering is physical pain.

As exchange-values, all commodities are merely definite quantities of congealed labour-time.

The education of all children, from the moment that they can get along without a mother’s care, shall be in state institutions.

Social reforms are never carried out by the weakness of the strong; but always by the strength of the weak.

The theory of Communism may be summed up in one sentence: Abolish all private property.

Keep people from their history, and they are easily controlled.

A heavy or progressive or graduated income tax is necessary for the proper development of Communism.

I do not like money, money is the reason we fight.

There is no royal road to science, and only those who do not dread the fatiguing climb of its steep paths have a chance of gaining its luminous summits.

Your favourite virtue – Simplicity.

Follow your own path, no matter what people say.

Everyone of our relationships with nature and man must be a definite expression of our real, individual life.

Communism is for us not a state of affairs which is to be established, an ideal to which reality have to adjust itself.

The history of all hitherto existing society is the history of class struggles.

You must be aware that the reward for labour, and quantity of labour, are quite disparate things.

A people without a heritage are easily persuaded.

I like to define biology as the history of the earth and all its life – past, present, and future.

It is, indeed, perhaps the greatest prospect of humanistic studies to contribute through an increasing knowledge of the history of cultural development to that gradual removal of prejudices which is the common aim of all science.

Freedom in capitalist society always remains about the same as it was in ancient Greek republics: Freedom for slave owners.

The Russians feared Ike. They didn’t fear me.

For the first time in the history of the world, every human being is now subjected to contact with dangerous chemicals, from the moment of conception until death.

It is not heroes that make history, but history that makes heroes.

Being president is like being a jackass in a hailstorm. There’s nothing to do but to stand there and take it.

We must act to shape and mold the future, and leave our imprint on events as they slip past into history.