Real knowledge is to know the extent of one's ignorance.

A man is literally what he thinks.

The simple things are also the most extraordinary things, and only the wise can see them.

If you have no problems, then you have no clue to what is going.

Where you stand depends on where you sit.

Courage is resistance to fear, mastery of fear - not absence of fear.

As the soft yield of water cleaves obstinate stone, So to yield with life solves the insolvable: To yield, I have learned, is to come back again.

Those who see the invisible can do the impossible.

Just remember, once you're over the hill you begin to pick up speed.

A single lie destroys a whole reputation of integrity.

All differences in this world are of degree, and not of kind, because oneness is the secret of everything.

The experience gathered from books, though often valuable,is but the nature of learning whereas the experience gained from actual life is of the nature of wisdom.

There is no question climate change is happening. The only arguable point is what part humans are playing in it.

A friend to all is a friend to none

No act of kindness, no matter how small, is ever wasted.

Dark and difficult times lie ahead. Soon we must all face the choice between what is right and what is easy.

Better mad with the rest of the world than wise alone.

If you don't stand for something you will fall for anything.

Each problem that I solved became a rule which served afterwards to solve other problems.

It takes a great deal of bravery to stand up to our enemies, but just as much to stand up to our friends.

If we know exactly where we're going, exactly how to get there, and exactly what we'll see along the way, we won't learn anything.