Optimism is a tool with a certain clear set of benefits: it fights depression, it promotes achievement and produces better health.

If we just wanted positive emotions, our species would have died out a long time ago.

In your own life, you should take particular care with endings, for their color will forever tinge your memory of the entire relationship and your willingness to reenter it.

The pursuit of happiness is enshrined in the Declaration of Independence as a right of all Americans, as well as on the self-improvement shelves of every American bookstore. Yet the scientific evidence makes it seem unlikely that you can change your level of happiness in any sustainable way. It suggests that we each have a fixed range for happiness just as we do for weight. And just as dieters almost always regain the weight they lose, sad people don't become lastingly happy, and happy people don't become lastingly sad.

You go into flow when your highest strengths are deployed to meet the highest challenges that come your way.

I'm trying to broaden the scope of positive psychology well beyond the smiley face. Happiness is just one-fifth of what human beings choose to do.

I believe that traditional wisdom is incomplete. A composer can have all the talent of Mozart and a passionate desire to succeed, but if he believes he cannot compose music, he will come to nothing. He will not try hard enough. He will give up too soon when the elusive right melody takes too long to materialize.