There are very many people who read simply to prevent themselves from thinking.

It is astonishing how much the word infinitely is misused: everything is infinitely more beautiful, infinitely better, etc. The concept must have something pleasing about it, or its misuse could not have become so general.

A book is a mirror: if an ape looks into it an apostle is hardly likely to look out.

The feeling of health can only be gained by sickness.

Ambition and suspicion always go together.

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

People who have read a good deal rarely make great discoveries. I do not say this in excuse of laziness, but because invention presupposes an extensive independent contemplation of things.