Inventive genius requires pleasurable mental activity as a condition for its vigorous exercise

But you can catch yourself entertaining habitually certain ideas and setting others aside; and that, I think, is where our personal destinies are largely decided.

In the history of the world the prize has not gone to those species which specialized in methods of violence, or even in defensive armor. In fact, nature began with producing animals encased in hard shells for defense against the ill of life. But smaller animals, without external armor, warm-blooded, sensitive, alert, have cleared those monsters off the face of the earth.

There are two principles inherent in the very nature of things, recurring in some particular embodiments whatever field we explore - the spirit of change, and the spirit of conservation. There can be nothing real without both. Mere change without conservation is a passage from nothing to nothing. . . . Mere conservation without change cannot conserve. For after all, there is a flux of circumstance, and the freshness of being evaporates under mere repetition.

The fact of the religious vision, and its history of persistent expansion, is our one ground for optimism. Apart from it, human life is a flash of occasional enjoyments lighting up a mass of pain and misery, a bagatelle of transient experience.

The vitality of thought is in adventure. Idea's won't keep. Something must be done about them. When the idea is new, its custodians have fervour, live for it, and, if need be, die for it. Their inheritors receive the idea, perhaps now strong and successful, but without inheriting the fervour; so the idea settles down to a comfortable middle age, turns senile, and dies.

That knowledge which adds greatness to character is knowledge so handled as to transform every phase of immediate experience.