Sometimes we stare so long at a door that is closing that we see too late the one that is open.

Great discoveries and improvements invariably involve the cooperation of many minds.

Ordinary people who know nothing of phonetics or elocution have difficulties in understanding slow speech composed of perfect sounds, while they have no difficulty in comprehending an imperfect gabble if only the accent and rhythm are natural.

A man, as a general rule, owes very little to what he is born with - a man is what he makes of himself.

What this power is, I cannot say... All I know is that it exists.

You cannot force ideas. Successful ideas are the result of slow growth. Ideas do not reach perfection in a day, no matter how much study is put upon them.

Don't keep forever on the public road, going only where others have gone and following one after the other like a flock of sheep. Leave the beaten track occasionally and dive into the woods.