A logical theory may be tested by its capacity for dealing with puzzles, and it is a wholesome plan, in thinking about logic, to stock the mind with as many puzzles as possible, since these serve much the same purpose as is served by experiments in physical science.

Just as we teach children to avoid being destroyed by motor cars if they can, so we should teach them to avoid being destroyed by cruel fanatics, and to this end we should seek to produce independence of mind, somewhat sceptical and wholly scientific, and to preserve, as far as possible, the instinctive joy of life that is natural to healthy children. This is the task of a liberal education: to give a sense of the value of things other than domination, to help create wise citizens of a free community, and through the combination of citizenship with liberty in individual creativeness to enable men to give to human life that splendour which some few have shown that it can achieve.

... it may be hoped that the white population of the world will soon cease to increase. The Asiatic races will be longer, and the negroes still longer, before their birth rate falls sufficiently to make their numbers stable without help of war and pestilence. But it is to be hoped that the religious prejudices which have hitherto hampered the spread of birth control will die out, and that ... the whole world will learn not to be unduly prolific. Until that happens, the benefits aimed at by socialism can only be partially realized, and the less prolific races will have to defend themselves against the more prolific by methods which are disgusting even if they are necessary.

I think that there is far too much work done in the world, that immense harm is caused by the belief that work is virtuous, and that what needs to be preached in modern industrial countries is quite different from what always has been preached.

Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense. If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time.

Friends, This is an occasion that I hardly know how to find words for. I am more touched than I can say, and more deeply than I can ever hope to express. I have to give my very warmest possible thanks to those who have worked to produce this occasion: to the performers, whose exquisite music, exquisitely performed, was so full of delight; to those who worked in less conspicuous ways, like my friend Mr Schoenman; and to all those who have given me gifts – gifts which are valuable in themselves, and also as expressions of an undying hope for this dangerous world. I have a very simple creed: that life and joy and beauty are better than dusty death, and I think when we listen to such music as we heard today we must all of us feel that the capacity to produce such music, and the capacity to hear such music, is a thing worth preserving and should not be thrown away in foolish squabbles. You may say it's a simple creed, but I think everything important is very simple indeed. I've found that creed sufficient, and I should think that a great many of you would also find it sufficient, or else you would hardly be here. But now I just want to say how it's difficult, when one has embarked upon a course which invites a greater or less degree of persecution and obloquy and abuse, to find instead that one is welcomed as I have been today. It makes one feel rather humble, and I feel I must try to live up to the feelings that have produced this occasion. I hope I shall; and I thank you from the bottom of my heart.

One should as a rule respect public opinion in so far as is necessary to avoid starvation and to keep out of prison, but anything that goes beyond this is voluntary submission to an unnecessary tyranny, and is likely to interfere with happiness in all kinds of ways.

As geological time goes, it is but a moment since the human race began and only the twinkling of an eye since the arts of civilization were first invented. In spite of some alarmists, it is hardly likely that our species will completely exterminate itself. And so long as man continues to exist, we may be pretty sure that, whatever he may suffer for a time, and whatever brightness may be eclipsed, he will emerge sooner or later, perhaps strengthened and reinvigorated by a period of mental sleep. The universe is vast and men are but tiny specks on an insignificant planet. But the more we realize our minuteness and our impotence in the face of cosmic forces, the more astonishing becomes what human beings have achieved.