A few observation and much reasoning lead to error; many observations and a little reasoning to truth.

The atmosphere of libraries, lecture rooms and laboratories is dangerous to those who shut themselves up in them too long. It separates us from reality like a fog.

The first duty of society is to give each of its members the possibility of fulfilling his destiny. When it becomes incapable of performing this duty it must be transformed.

Intuition comes very close to clairvoyance; it appears to be the extrasensory perception of reality.

Gigantic sums are now required to maintain prisons and insane asylums and protect the public against gangsters and lunatics. Why do we preserve these useless and harmful beings? The abnormal prevent development of the normal.

Those who desire to rise as high as our human condition allows, must renounce intellectual pride, the omnipotence of clear thinking, belief in the absolute power of logic.

Like hatred, jealousy is forbidden by the laws of life because it is essentially destructive.

The love of beauty in its multiple forms is the noblest gift of the human cerebrum.

All great men are gifted with intuition. They know without reasoning or analysis, what they need to know.

Comforts and syphilis are the greatest enemies of mankind.

All of us, at certain moments of our lives, need to take advice and to receive help from other people.

The most efficient way to live reasonably is every morning to make a plan of one's day and every night to examine the results obtained.

Science has to be understood in its broadest sense, as a method for comprehending all observable reality, and not merely as an instrument for acquiring specialized knowledge.

To what extent is any given man morally responsible for any given act? We do not know.

Hard conditions of life are indispensable to bringing out the best in human personality.

Life leaps like a geyser for those who drill through the rock of inertia.

The quality of life is more important than life itself.

Perhaps I will stay in Chicago and operate on human beings instead of on dogs. From a business standpoint, it would be excellent. But, as I hate medical practice, I would like better to make little money in doing scientific work than a great deal in doing surgical operations.

The German government has taken energetic measures against the propagation of the defective, the mentally diseased, and the criminal.

In man, the things which are not measurable are more important than those which are measurable.

Religion brings to man an inner strength, spiritual light, and ineffable peace.

Everyone makes a greater effort to hurt other people than to help himself.

The Asiatics and the Africans, such as the Russians, the Arabs, the Hindus, are increasing with marked rapidity. Never have the European races been in such great peril as today.

The difficulty of finding organs suitable for transplantation on man must be met.

Man cannot remake himself without suffering, for he is both the marble and the sculptor.