Some theories are good for nothing except to be argued about.

We are obliged to regard many of our original minds as crazy at least until we have become as clever as they are.

Just as there are polysyllabic words that say very little, so there are also monosyllabic words of infinite meaning.

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

I made the journey to knowledge like dogs who go for walks with their masters, a hundred times forward and backward over the same territory; and when I arrived I was tired.

Food probably has a very great influence on the condition of men. Wine exercises a more visible influence, food does it more slowly but perhaps just as surely. Who knows if a well-prepared soup was not responsible for the pneumatic pump or a poor one for a war?

A good metaphor is something even the police should keep an eye on.