He who knows, does not speak. He who speaks, does not know.

Worthless people live only to eat and drink; people of worth eat and drink only to live.

Experience without theory is blind, but theory without experience is mere intellectual play.

The only real valuable thing is intuition.

Which death is preferably to every other? ‚The unexpected‘.

To me, if life boils down to one thing, it’s movement. To live is to keep moving.

It is the heart always that sees, before the head can see.

Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.

You can know or not know how a car runs and still enjoy riding in a car.

He who has made a fair compact with poverty is rich.

Though silence is not necessarily an admission, it is not a denial, either.

There is much pleasure to be gained from useless knowledge.

Mystical explanations are thought to be deep; the truth is that they are not even shallow.

Knowledge is knowing that we cannot know.

The man of science is a poor philosopher.

Scientists have become the bearers of the torch of discovery in our quest for knowledge.

A little learning is a dangerous thing, but we must take that risk because a little is as much as our biggest heads can hold.

It is the privilege of the gods to want nothing, and of godlike men to want little.

But Satan now is wiser than of yore, and tempts by making rich, not making poor.

It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.

Science is not everything, but science is very beautiful.

One must know oneself. If this does not serve to discover truth, it at least serves as a rule of life and there is nothing better.

All that mankind has done, thought or been: it is lying as in magic preservation in the pages of books.

I’m speaking for all of us. I’m the spokesman for a generation.

The older I get the more wisdom I find in the ancient rule of taking first things first. A process which often reduces the most complex human problem to a manageable proportion.

Nature puts no question and answers none which we mortals ask. She has long ago taken her resolution.

In everything one thing is impossible: rationality.

You are not only responsible for what you say, but also for what you do not say.

Fill your bowl to the brim and it will spill. Keep sharpening your knife and it will blunt.

Dost thou love life? Then do not squander time, for that is the stuff life is made of.

A physician is not angry at the intemperance of a mad patient, nor does he take it ill to be railed at by a man in fever. Just so should a wise man treat all mankind, as a physician does his patient, and look upon them only as sick and extravagant.

The proper study of Man is anything but Man; and the most improper job of any man, even saints (who at any rate were at least unwilling to take it on), is bossing other men. Not one in a million is fit for it, and least of all those who seek the opportunity.

The life so short, the craft so long to learn.

The only real security that a man can have in this world is a reserve of knowledge, experience and ability.

This is the truth: as from a fire aflame thousands of sparks come forth, even so from the Creator an infinity of beings have life and to him return again.

The less you know, the more you believe.

If you were to destroy the belief in immortality in mankind, not only love but every living force on which the continuation of all life in the world depended, would dry up at once.

The universe seems neither benign nor hostile, merely indifferent.

The finite is annihilated in the presence of the infinite, and becomes a pure nothing. So our spirit before God, so our justice before divine justice.

An ounce of practice is worth more than tons of preaching.

Nothing is more terrible than activity without insight.

An intellectual is a man who takes more words than necessary to tell more than he knows.

There is no wealth but life.

Whatever the universal nature assigns to any man at any time is for the good of that man at that time.

Electrical science has revealed to us the true nature of light, has provided us with innumerable appliances and instruments of precision, and has thereby vastly added to the exactness of our knowledge.

No; we have been as usual asking the wrong question. It does not matter a hoot what the mockingbird on the chimney is singing. The real and proper question is: Why is it beautiful?

Reality is a sliding door.

The more extensive a man’s knowledge of what has been done, the greater will be his power of knowing what to do.

God gives the nuts, but he does not crack them.

Eternal nothingness is fine if you happen to be dressed for it.

For one swallow does not make a summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy.

We still do not know one thousandth of one percent of what nature has revealed to us.

Science has not yet taught us if madness is or is not the sublimity of the intelligence.

Some people see things that are and ask, Why? Some people dream of things that never were and ask, Why not? Some people have to go to work and don’t have time for all that.

There are worse crimes than burning books. One of them is not reading them.

No one can pass through life, any more than he can pass through a bit of country, without leaving tracks behind, and those tracks may often be helpful to those coming after him in finding their way.

Dying is one of the few things that can be done as easily lying down.

I believe that it is better to tell the truth than a lie. I believe it is better to be free than to be a slave. And I believe it is better to know than to be ignorant.

The golden rule is that there are no golden rules.

To be or not to be is not a question of compromise. Either you be or you don’t be.

In the End, we will remember not the words of our enemies, but the silence of our friends.