"Happiness is its own reward, but it doesn't stop there. Happy people are accepting of themselves, so they don't spend precious time in regret. They accept others, too, so are free to love people as they are, rather than expending energy trying to do a repair job on everyone in sight. They look positively to the future so they don't spend a lot of time in worry or fear. They are engaged with life as a wonderful adventure in which they are here to give their best. The zest with which they encounter life is contagious; people are drawn into their orbit and success seems to be attracted as well. They're healthier too. A study reported recently in the Journal of Neurology found that happy older people are less likely to develop Alzheimer's disease. Studies have also found that folks who are happy are less likely to die prematurely even develop colds.

"As I've thought, read, and practiced the art of happiness, I've come to understand a few things: first, that the search for happiness is at the root of all human activity throughout the ages; second, that happiness must be experienced in this moment or risk never being felt at all. While we can get nostalgic for the past — oh, I used to be so happy — or wistful about the future — someday I will be happy — it is now, in this very moment, that we must create the only happiness that we can count on.

"Most important, I've learned that while scientists have recently discovered we each have a genetic happiness set point, a place on the emotional spectrum we tend to drift toward, it accounts for only 40-50 percent of our happiness (which they determined by studying twins raised apart). What that means is that we all can experience more contentment and joyfulness no matter who we are. For as of yet, no one has discovered an upward limit on good feelings.

"In a very real sense, happiness is the ultimate makeover. Why else do we spend money and time on fixing our houses, our bodies, our relationships except that we want to be happier? Rather than trying to shore up baggy eyelids or redo mismatched furniture in an attempt to experience greater overall satisfaction and enjoyment, why not go directly to the source — cultivating the mental and emotional outlooks that will generate a sense of joyfulness independent of couch fabric or lipstick brand?

"As I studied and practiced, I've come to understand that happiness is a feeling that arises as a result of thoughts we choose to hold and actions we choose to take to increase those good thoughts. In this way, we think our way to happiness. At the heart of this book is the realization that the mind is a powerful thing and its power can be used to make us happy or miserable. We can concentrate on how the world has done us wrong or the ways it does us right. We can focus on where we're stuck or how we're free. We can take the opportunity to notice the ordinary miracles around us. We can find ways to truly enjoy, even to relish, the moments of our lives.

"While certain thinking creates happiness, happiness itself may also create better thinking: '[T]here's a growing body of evidence that people think more effectively and expansively when they are happy than when they are not,' noted Professor Barry Schwartz in a recent speech to Swarthmore graduates. For instance, doctors who were given bags of candy before seeing patients — a happiness booster — increased their accuracy and speed of diagnosis.

"Before psychology got interested in happiness, about ten years ago, this topic was left to philosophers. Since Aristotle, philosophers have distinguished between hedonistic happiness, happiness as a feeling of pleasure or contentment, and eudaimonistic happiness, which arises out of satisfaction with one's actions and character. Recently positive psychology has made a similar distinction between pleasure and gratification, noting that since pleasure is fleeting and gratification longer lasting, it is better to pursue gratification to experience 'authentic' happiness. The distinction may be intellectually useful, but I think it fails to take into account the uniqueness of each person and therefore what each of us may need.

"Take me, for instance. I knew a lot about the happiness that comes from living your strengths and values (what Martin Seligman calls the path of gratification). But until recently I knew precious little about enjoying my life moment to moment, the pleasure path. What I want to encourage you to do, dear reader, is understand which of practices and mind-training exercises that can be used to achieve happiness."