The Power of Negative Thinking - WSJ.com: " . . . studies suggest that peppy affirmations designed to lift the user's mood through repetition and visualizing future success often achieve the opposite of their intended effect. Fortunately, both ancient philosophy and contemporary psychology point to an alternative: a counter intuitive approach that might be termed "the negative path to happiness." This approach helps to explain some puzzles, such as the fact that citizens of more economically insecure countries often report greater happiness than citizens of wealthier ones. Or that many successful business people reject the idea of setting firm goals.
One pioneer of the "negative path" was the New York psychotherapist Albert Ellis, who died in 2007. He rediscovered a key insight of the Stoic philosophers of ancient Greece and Rome: that sometimes the best way to address an uncertain future is to focus not on the best-case scenario but on the worst.
Seneca the Stoic was a radical on this matter. If you feared losing your wealth, he once advised, "set aside a certain number of days, during which you shall be content with the scantiest and cheapest fare, with coarse and rough dress, saying to yourself the while: 'Is this the condition that I feared?' ". . . ."