If you can't explain it simply, you don't understand it well enough.

The real solution lies in a world in which charity will have become unnecessary.

It is not enough for the teacher to love the child. She must first love and understand the universe. She must prepare herself, and truly work at it.

The first principle is that you must not fool yourself and you are the easiest person to fool.

To every action there is always an equal and opposite or contrary, reaction

A little knowledge is a dangerous thing. So is a lot.

What we know is a drop, what we don't know is an ocean.

The more I read, the more I acquire, the more certain I am that I know nothing.

The man who is fond of books is usually a man of lofty thought, and elevated opinions.

If I have seen further it is by standing on the shoulders of Giants.

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.

Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.

The deepest sin against the human mind is to believe things without evidence.

All knowledge that the world has ever received comes from the mind; the infinite library of the universe is in our own mind.

They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance.

I don't look on poetry as closed works. I feel they're going on all the time in my head and I occasionally snip off a length.

It isn't what we don't know that gives us trouble, it's what we know that ain't so.

Opinion is the medium between knowledge and ignorance.

The highest result of education is tolerance.