A man's acts are partly determined by spontaneous impulse, partly by the conscious and unconscious effects of the various groups to which he belongs.

Pure mathematics consists entirely of assertions to the effect that, if such and such a proposition is true of anything, then suchand such another proposition is true of that thing.... Thus mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.

Meantime, the world in which we exist has other aims. But it will pass away, burnt up in the fire of its own hot passions; and from its ashes will spring a new and younger world, full of fresh hope, woth the light of morning in its eyes.

It is one of the defects of modern higher education that it has become too much a training in the acquisition of certain kinds of skill, and too little an enlargement of the mind and heart by an impartial survey of the world.

Our great democracies still tend to think that a stupid man is more likely to be honest than a clever man, and our politicians take advantage of this prejudice by pretending to be even more stupid than nature has made them.

Herd pressure is to be judged by two things: first, its intensity, and second, its direction.

The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.