Mathematicians, like cows in the dark, all look alike to me.

There are men who teach best by not teaching at all.

The real enemy is the man who tries to mold the human spirit so that it will not dare to spread its wings.

We must not overlook the role that extremists play. They are the gadflies that keep society from being too complacent or self-satisfied; they are, if sound, the spearhead of progress. If they are fundamentally wrong, free discussion will in time put an end to them.

A patient had a 50-50 chance of benefiting from visiting a physician as of 1910. Medicine was more like voodoo than science until the 20th Century.

The student is to collect and evaluate facts. The facts are locked up in the patient.

Science, in the very act of solving problems, creates more of them.