The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man. – G.B. Shaw, Man and Superman, 1903

The number of those who undergo the fatigue of judging for themselves is very small indeed. – Richard Brinsley Sheridan, The Critic, 1799

What we call human nature in actuality is human habit. – Jewel Kilcher, Pieces of You

We must not overlook the role that extremists play. They are the gadflies that keep society from being too complacent. – Abraham Flexner, Universities, 1930