Without effort and change, human life cannot remain good. It is not a finished Utopia that we ought to desire, but a world where imagination and hope are alive and active.

Every philosophical problem, when it is subjected to the necessary analysis and justification, is found either to be not really philosophical at all, or else to be, in the sense in which we are using the word, logical.

There have been poverty, pestilence, and famine, which were due to man's inadequate mastery of nature. There have been wars, oppressions and tortures which have been due to men's hostility to their fellow men.

Science may set limits to knowledge, but should not set limits to imagination.

My own view on religion is that of Lucretius. I regard it as a disease born of fear and as a source of untold misery to the human race. I cannot, however, deny that it has made some contributions to civilisation. It helped in early days to fix the calendar, and it caused Egyptian priests to chronicle eclipses with such care that in time they became able to predict them. These two services I am prepared to acknowledge, but I do not know of any others.

You may reasonably expect a man to walk a tightrope safely for ten minutes; it would be unreasonable to do so without accident for two hundred years.

Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical.