If WE claim only reasonable probability, it will be as much as men who love the truth can ever at any given moment hope to have within their grasp.

The more rational statement is that we feel sorry because we strike, afraid because we tremble, and not that we cry, strike, or tremble because we are sorry, angry, or fearful as the case may be.

Life is one long struggle between conclusions based on abstract ways of conceiving cases, and opposite conclusions prompted by our instinctive perception of them.

The old question of whether there is design is idle. The real question is what is the world, whether or not it have a designer--and that can be revealed only by the study of all nature's particulars.

Genius... means little more than the faculty of perceiving in an unhabitual way.

It is only by risking our persons from one hour to another that we live at all. And often enough our faith beforehand in an uncertified result is the only thing that makes the result come true.

... if we take the universe of 'fitting,' countless coats 'fit' backs, and countless boots 'fit' feet, on which they are not practically fitted; countless stones 'fit' gaps in walls into which no one seeks to fit them actually. In the same way countless opinions 'fit' realities, and countless truths are valid, tho no thinker ever thinks them.