“It is not the consciousness of man that determines his existence – rather, it is his social existence that determines his consciousness.”

Science may be described as the art of systematic oversimplification.

The game of science is, in principle, without end.

The essential feature of dualist-interactionism is that the mind and brain are independent entities and that they interact by quantum physics.

“It can’t happen here” is always wrong: a dictatorship can happen anywhere.

A theory that explains everything, explains nothing.

If our civilization is to survive, we must break with the habit of deference to great men.

The simple truth is that truth is hard to come by, and that once found may easily be lost again.

The quest for precision is analogous to the quest for certainty, and both should be abandoned.

Every intellectual has a very special responsibility. He has the privilege and the opportunity of studying.

The aim of argument, or of discussion, should not be victory but progress.

If you can’t say it simply and clearly, keep quiet, and keep working on it till you can.

“We don’t know anything” and believed that this was the most important philosophical truth.

While differing widely in the various little bits we know, in our infinite ignorance we are all equal.

We can all participate in the heritage of man. We all can help to preserve it. And we can all make our own modest contribution to it.

We all have an unscientific weakness for being always in the right, and this weakness seems to be particularly common among professional and amateur politicians.

History has no meaning.

But I must at the very beginning lay down this principle – friendship can only exist between good men.

Being is essentially different from a being, from beings.

The holes of oblivion do not exist. Nothing human is that perfect, and there are simply too many people in the world to make oblivion possible. One man will always be left alive to tell the story.

Freedom is the source from which all significations and all values spring. It is the original condition of all justification of existence.

The question of existence never gets straightened out except through existing itself.

To be is to do.

This is the most profound question in life: ‘What is the nature of my existence?’

There is no justification for present existence other than its expansion into an indefinitely open future.