Man lives by habits indeed, but what he lives for is thrill and excitements. ... From time immemorial war has been ... the supremely thrilling excitement.

Faith means belief in something concerning which doubt is still theoretically possible ... faith is the readiness to act in a cause the prosperous issue of which is not certified to us in advance.

If, then, you wish to insure the interest of your pupils, there is only one way to do it; and that is to make certain that they have something in their minds to attend with, when you begin to talk. That something can consist in nothing but a previous lot of ideas already interesting in themselves, and of such a nature that the incoming novel objects which you present can dovetail into them and form with them some kind of a logically associated or systematic whole.

Truth lives, in fact, for the most part on a credit system

There is no doubt that healthy-mindedness is inadequate as a philosophical doctrine, because the evil facts which it refuses positively to account for are a genuine portion of reality; and they may after all be the best key to life's significance, and possibly the only openers of our eyes to the deepest levels of truth.

In order to disprove the assertion that all crows are black, one white crow is sufficient.

The first effect of the mind growing cultivated is that processes once multiple get to be performed in a single act. Lazarus has called this the progressive "condensation" of thought. ... Steps really sink from sight. An advanced thinker sees the relations of his topics is such masses and so instantaneously that when he comes to explain to younger minds it is often hard ... Bowditch, who translated and annotated Laplace's Méchanique Céleste, said that whenever his author prefaced a proposition by the words "it is evident," he knew that many hours of hard study lay before him.