The passions grafted on wounded pride are the most inveterate; they are green and vigorous in old age.

The combative instinct is a savage prompting by which one man's good is found in another's evil.

Science is nothing but developed perception, interpreted intent, common sense rounded out and minutely articulated.

Eternal vigilance is the price of knowledge.

Rejection is a form of self-assertion. You have only to look back upon yourself as a person who hates this or that to discover what it is that you secretly love.

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

Nothing you can lose by dying is half as precious as the readiness to die, which is man's charter of nobility.