Science is a wonderful thing if one does not have to earn one's living at it. One should earn one's living by work of which one is sure one is capable. Only when we do not have to be accountable to anybody can we find joy in scientific endeavor.

I am of the opinion that all the finer speculations in the realm of science spring from a deep religious feeling, and that without such feeling they would not be fruitful.

Hunger, love, pain, fear are some of those inner forces which rule the individual's instinct for self preservation.

The mind that opens to a new idea never returns to its original size

This is a time, when there seems to be a particular need for friends of wisdom and truth to join together.

Sometimes one pays most for the things one gets for nothing.

I'd rather be an optimist and a fool than a pessimist and right.