It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.
A smart man makes a mistake, learns from it, and never makes that mistake again. But a wise man finds a smart man and learns from him how to avoid the mistake altogether.
There are things known and there are things unknown, and in between are the doors of perception.
Men create real miracles when they use their god-given courage and intelligence.
Smartness runs in my family. When I went to school I was so smart my teacher was in my class for five years.
We could have human intelligence in orbit around Mars, building things there.
“The habits of a vigorous mind are born in contending with difficulties.”
It is not clear that intelligence has any long-term survival value.
I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet earth.
There are no great limits to growth because there are no limits of human intelligence, imagination, and wonder.
To expect the unexpected shows a thoroughly modern intellect.
Military intelligence is a contradiction in terms.
We have now sunk to a depth at which restatement of the obvious is the first duty of intelligent men.
The true sign of intelligence is not knowledge but imagination.