The chessboard is the world, the pieces are the phenomena of the Universe, the rules of the game are what we call the laws of Nature, the player on the other sideis hidden from us.

Science is organized common sense where many beautiful theory was killed by an ugly fact.

Truly it has been said, that to a clear eye the smallest fact is a window through which the infinite may be seen.

It is not to be forgotten that what we can rational grounds for our benefits are often extremely irrational attempts to justify our instincts.

We live in a world which is full of misery and ignorance, and the plain duty of each of us is to try to make the little corner he can influence somewhat less miserable and somewhat less ignorant than it was before he entered it.

The only freedom I care about is the freedom to do right; the freedom to do wrong I am ready to part with on the cheapest terms to anyone who will take it of me.

I take it that the good of mankind means the attainment, by every man, of all the happiness which he can enjoy without diminishing the happiness of his fellow men.

Ecclesiasticism in science is only unfaithfulness to truth.

Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. ... Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect, do not pretend that conclusions are certain which are not demonstrated or demonstrable.

Life is like walking along a crowded street--there always seem to be fewer obstacles to getting along on the opposite pavement--and yet, if one crosses over, matters are rarely mended.