For many people, an excuse is better than an achievement because an achievement, no matter how great, leaves you having to prove yourself again in the future; but an excuse can last for life.

It is to escape the responsibility for failure that the weak so eagerly throw themselves into grandiose undertakings.

It is often the failure who is the pioneer in new lands, new undertakings, and new forms of expression.

One word characterizes the most strenuous of the efforts for the advancement of science that I have made perservereingly during fifty-five years; that word is failure