Everybody should do at least two things each day that he hates to do, just for practice.

The good we do today becomes the happiness of tomorrow.

Is life worth living? It all depends on the liver.

Feed the growing human being, feed him with the sort of experience for which from year to year he shows a natural craving, and he will develop in adult life a sounder sort of mental tissue, even though he may seem to be 'wasting' a great deal of his growing time, in the eyes of those for whom the only channels of learning are books and verbally communicated information.

True ideas are those that we can assimilate, validate, corroborate, and verify. False ideas are those that we cannot

If the topic be highly abstract, show its nature by concrete examples. If it be unfamiliar, trace some point of analogy in it with the known. If it be inhuman, make it figure as part of a story. If it be difficult, couple its acquisition with some prospect of personal gain. Above all things, make sure that it shall run through certain inner changes, since no unvarying object can possibly hold the mental field for long.

... no bell in us tolls to let us know for certain when truth is in our grasp.