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.

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

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

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

The cell is immortal. It is merely the fluid in which it floats that degenerates. Renew this fluid at regular intervals, give the cells what they require for nutrition, and as far as we know, the pulsation of life can go on forever.

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.