Man cannot remake himself without suffering, for he is both the marble and the sculptor.
The quality of life is more important than life itself.
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.
A few observation and much reasoning lead to error; many observations and a little reasoning to truth.
Intuition comes very close to clairvoyance; it appears to be the extrasensory perception of reality.
Like hatred, jealousy is forbidden by the laws of life because it is essentially destructive.
Religion brings to man an inner strength, spiritual light, and ineffable peace.
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.
Hard conditions of life are indispensable to bringing out the best in human personality.
The German government has taken energetic measures against the propagation of the defective, the mentally diseased, and the criminal.
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.
In man, the things which are not measurable are more important than those which are measurable.
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.