Science is simply common sense at its best—that is, rigidly accurate in observation, and merciless to fallacy in logic.
The improver of natural knowledge absolutely refuses to acknowledge authority as such.
Every great advance in natural knowledge has involved the absolute rejection of authority.
The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability.
Sit down before fact as a little child, be prepared to give up every preconceived notion, follow humbly wherever and to whatever abysses nature leads, or you shall learn nothing.
The chess-board is the world; the pieces are the phenomena of the universe; the rules of the game are what we call the laws of Nature.
Time is not a thing, thus we can neither waste nor save it; it is always with us.
Try to learn something about everything and everything about something.
Make up your mind to act decidedly and take the consequences. No good is ever done in this world by hesitation.
The great end of life is not knowledge but action.
无人应为其天性缺陷受全责；但若不加努力改正，便应受责。
我所见人与动物最显著的区别不在于理性，而在于运用理性的能力程度。
我认为，一个人在青年时期得到如此训练，使身体随时听命于意志，便是受过博雅教育。
自由与秩序并非不相容；真理即力量；自由讨论是真理的生命。
热切而强烈的渴望，是一切有效努力的泉源。
目标的耐心与坚韧，其价值两倍于聪明。
科学的大悲剧——一个丑陋的事实扼杀了一个美丽的假说。
在我看来，“一知半解是危险的事”这句格言本身就很危险。
关键不在于我们相信什么，而在于为何相信；道德责任由此开始。
逻辑后果是愚者的稻草人，却是智者的灯塔。