Many intelligent people, when about to write . . . , force on their minds a certain notion about style, just as they screw up their faces when they sit for their portraits.

What a blessing it would be if we could open and shut our ears...as easily as we open and shut our eyes.

Do not say hypothesis, and even less theory: say way of thinking.

Never undertake anything for which you wouldn't have the courage to ask the blessings of heaven.

Much reading has brought upon us a learned barbarism.

In every man there is something of all men.

There is no greater impediment to progress in the sciences than the desire to see it take place too quickly.