What is more important in life than our bodies or in the world than what we look like?

Happiness is impossible, and even inconceivable, to a mind without scope and without pause, a mind driven by craving, pleasure, or fear. To be happy, you must be reasonable, or you must be tamed. You must have taken the measure of your powers, tasted the fruits of your passion, and learned your place in the world and what things in it can really serve you. To be happy, you must be wise.

There is a kind of courtesy in skepticism. It would be an offense against polite conventions to press our doubts too far.

...science is nothing but developed perception, interpreted intent, common-sense rounded out and minutely articulated. It is therefore as much an instinctive product, as much a stepping forth of human courage in the dark, as is any inevitable dream or impulsive action.

Everything in nature is lyrical in its ideal essence, tragic in its fate, and comic in its existence.

There is nothing sacred about convention; there is nothing sacred about primitive passions or whims; but the fact that a convention exists indicates that a way of living has been devised capable of maintaining itself.

My atheism, like that of Spinoza, is true piety towards the universe and denies only gods fashioned by men in their own image, to be servants of their human interests.