Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.
What sculpture is to a block of marble, education is to a human soul.
In mathematics you don't understand things. You just get used to them.
All knowledge that the world has ever received comes from the mind; the infinite library of the universe is in our own mind.
A thought is an idea in transit.
Reading is to the mind what exercise is to the body.
To educate a person in the mind but not in morals is to educate a menace to society.
Those who fail to learn the lessons of history are doomed to repeat them.
Most people have never learned that one of the main aims in life is to enjoy it.
Necessity is the mother of invention.
Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.
It is possible to fly without motors, but not without knowledge and skill.
Imagination is more important than knowledge.
The secret of life is not enjoyment but education through experience.
All stable processes we shall predict. All unstable processes we shall control.
The books that the world calls immoral are books that show the world its own shame.
Investigate, educate and organize.
Patience is a virtue, and I'm learning patience. It's a tough lesson.
God created man in His own image, says the Bible; philosophers reverse the process: they create God in theirs.
A little knowledge is a dangerous thing. So is a lot.
If you're teaching today what you were teaching five years ago, either the field is dead or you are.