The first people totalitarians destroy or silence are men of ideas and free minds.

Few new truths have ever won their way against the resistance of established ideas save by being overstated.

Science cannot destroy the consciousness of freedom, without which there is no morality and no art, but it can refute it.

Liberty and equality, spontaneity and security, happiness and knowledge, mercy and justice - all these are ultimate human values, sought for themselves alone; yet when they are incompatible, they cannot all be attained, choices must be made, sometimes tragic losses accepted in the pursuit of some preferred ultimate end.

Philosophers are adults who persist in asking childish questions.

The very desire for guarantees that our values are eternal and secure in some objective heaven is perhaps only a craving for the certainties of childhood or the absolute values of our primitive past.

When one is engaged in a desperate defense of one's world and its values, nothing can be given away, any breach in the walls might be fatal, every point must be defended to the death.