If you know that things are bound to happen whatever you do, then you may feel free to give up the fight against them.

It is the rule which says that the other rules of scientific procedure must be designed in such a way that they do not protect any statement in science against falsification.

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

It is part of my thesis that all our knowledge grows only through the correcting of our mistakes.

The moral decisions of others should be treated with respect, as long as such decisions do not conflict with the principle of tolerance.

Science is not a system of certain, or -established, statements; nor is it a system which steadily advances towards a state of finality... And our guesses are guided by the unscientific, the metaphysical (though biologically explicable) faith in laws, in regularities which we can uncover-discover. Like Bacon, we might describe our own contemporary science-'the method of reasoning which men now ordinarily apply to nature'-as consisting of 'anticipations, rash and premature' and as 'prejudices'.

It is impossible to speak in such a way that you cannot be misunderstood.