Our theory had been that optimism matters because it produces persistence. - Martin E P Seligman

For example, if I promise you one thousand dollars to turn to this page, you will probably choose to do so, and you will succeed. If, however, I promise you one thousand dollars to contract the pupil of your eye, using only willpower, you may choose to do it, but that won’t matter. You are helpless to contract your pupil. Page turning is under your voluntary control; the muscles that change your pupillary size are not.

In the struggle to cure syphilis in the first decade of the century, Paul Ehrlich concocted a drug, 606, that worked by poisoning Treponema pallidum, the spirochete that causes syphilis. It was called 606 because before it Ehrlich concocted 605 other drugs, none of which worked. Ehrlich, presumably, experienced 605 defeats but persisted.

With patients, he pushed and pushed until he had persuaded them to give up the irrational beliefs that sustained their depression. “What do you mean you can’t live without love?” he would cry. “Utter nonsense. Love comes rarely in life, and if you waste your life mooning over its all too ordinary absence, you are bringing on your own depression. You are living under a tyranny of should’s. Stop ‘should-ing’ on yourself!