In considering irregular appearances, there are certain very natural mistakes which must be avoided.

Thinking you know when in fact you don't is a fatal mistake, to which we are all prone

On the one hand, philosophy is to keep us thinking about things that we may come to know, and on the other hand to keep us modestly aware of how much that seems like knowledge isn't knowledge

For love of domination we must substitute equality; for love of victory we must substitute justice; for brutality we must substitute intelligence; for competition we must substitute cooperation. We must learn to think of the human race as one family.

True happiness for human beings is possible only to those who develop their godlike potentialities to the utmost.

To be able to concentrate for a considerable time is essential to difficult achievement.

But it is just this characteristic of simplicity in the laws of nature hitherto discovered which it would be fallacious to generalize, for it is obvious that simplicity has been a part cause of their discovery, and can, therefore, give no ground for the supposition that other undiscovered laws are equally simple.