A man must have faith in himself to be of any use in the world. There may be very little on which to base it — no matter, but faith in one's powers, in one's mission is essential to success. Confidence once won, the rest follows naturally; and with strong faith in himself a man becomes a local center for its radiation. St. Francis, St. Theresa, Ignatius Loyola, Florence Nightingale, the originator of every cult or sect or profession has possessed this infective faith. And in the ordinary everyday work of the doctor confidence, assurance (in the proper sense of the word) is an asset without which it is very difficult to succeed.

The Faith that Heals (1910)