When people talk as if the Crusades were nothing more than an aggressive raid against Islam, they seem to forget in the strangest way that Islam itself was only an aggressive raid against the old and ordered civilization in these parts. I do not say it in mere hostility to the religion of Mahomet; I am fully conscious of many values and virtues in it; but certainly it was Islam that was the invasion and Christendom that was the thing invaded.

Science only means knowledge; and for [Greek] ancients it did only mean knowledge. Thus the favorite science of the Greeks was Astronomy, because it was as abstract as Algebra. ... We may say that the great Greek ideal was to have no use for useful things. The Slave was he who learned useful things; the Freeman was he who learned useless things. This still remains the ideal of many noble men of science, in the sense they do desire truth as the great Greeks desired it; and their attitude is an external protest against vulgarity of utilitarianism.

Instead of the machine being a giant to which the man is the pygmy, we must at last reverse the proportions until man is a giant to whom the machine is the toy.

Even in a minute instance, it is best to look first to the main tendencies of Nature. A particular flower may not be dead in early winter, but the flowers are dying; a particular pebble may never be wetted with the tide, but the tide is coming in. To the scientific eye all human history is a series of collective movements, destructions or migrations, like the massacre of flies in winter or the return of birds in spring.

Pride juggles with her toppling towers, They strike the sun and cease, But the firm feet of humility They grip the ground like trees.

We cannot fling ourselves into the blank future; we can only call up images from the past. This being so, the important principle follows, that how many images we have largely depends on how much past we have.

Life is serious all the time, but living cannot be. You may have all the solemnity you wish in your neckties, but in anything important (such as sex, death, and religion), you must have mirth or you will have madness.