"A dance bandleader who died recently at the age of 97 liked to tell people he was in 'the happiness business.' Aren't we all, in a sense? Everyone wants to be happy, as the Dalai Lama often points out. In our fractious world, this may be the one point on which we all agree. But when it comes to the question What is happiness? there are probably six billion different answers — one for each person on the globe. If we're observant, we may know when other people are happy: the 'Duchenne smile,' produced by involuntary muscle contractions around the eyes and mouth, is a universal, if subtle giveaway as recognizable to a Papua New Guinean tribesman as to a British parliamentarian. What we generally can't tell is why someone's happy. Half the time, we can't even say why for ourselves. The right to pursue happiness is a wonderful opportunity, but it doesn't automatically move us closer to an answer. That may be the work of a lifetime.

"Indeed, for thousands of years philosophers have argued that finding happiness is the purpose of life. The Greeks thought it was our highest moral duty. The Utilitarians, centuries later, said it was our duty to make sure everybody else was happy too. Spiritual leaders have been of mixed mind about happiness: the Christian church never has quite resolved whether it's strictly a reward of the next life or a virtue in the here and now. To the Buddhists happiness is the fruit of awakening — freedom from the agony of desire. By the time Sigmund Freud came along and psychology became our de facto religion, happiness seemed like a loaded gun. Whatever made us happy probably wasn't good for us; the pursuit of happiness was fraught with inner conflict.

"Now, at long last, positive emotions like joy, affection, awe, and humor are in the spotlight. It's not just okay to seek happiness, it's essential. Our best hope of having a good life — and a safe planet — is to develop the kindlier, friendlier, more optimistic side of our nature.

"A green light to pursue happiness is terrific, but where to begin? Do we look to our surroundings — work, family, our social sphere? Or do we look within, at the desires and personality traits that predispose us to be happy, and the genetic or behavioral quirks that prevent us from feeling unalloyed joy? Some happiness mavens have argued that we're only as happy as we choose to be. If we're not happy, it means we've fallen down on the job. Not a very happy prospect. Now, brain science is coming to our rescue, with exciting new findings about neuroplasticity, the brain's ability to adapt and change. Pursuing happiness is not a moral issue but a practical one. Though we inherit a certain potential for happiness, we can enhance it by forming new neural pathways. With practices like meditation and cognitive training, we can reset our brains to experience the world the way naturally happy people take for granted.

"Happy people see life as opportunity. Challenges are blessings in disguise. When we feel happy, our minds are open and expansive. Conversely, when we're open and expansive we feel happy. Happiness is an 'upward spiral,' as one researcher describes it. It makes us not only feel better but be better — better able to forge fulfilling relationships, find meaningful pursuits, and handle the vicissitudes of life. Happiness helps us stay healthy and whole no matter what the circumstances. Best of all, we can pass it on to those around us.

"If you've picked up this book — or been given it by someone else — happiness is obviously on your mind. Maybe you're coming through a bad patch and wondering how to turn your life around. Maybe your life is pretty good but you think it could be even better. Either way, you'll want to explore what makes you happy. Finding answers means asking the right questions. That's where this book comes in. If you've thumbed through it, you've noticed the format is a bit different from most inspirational reading. There are twenty dialogues — hypothetical conversations — between a seeker and a wise friend. Each dialogue focuses on a quality or condition that impacts happiness, such as health, wealth, uncertainty, or time. At first glance, you may think the seeker's situation isn't the same as yours, so why would these exchanges have any relevance for you? Take another look. Behind the seeker's questioning lies the larger issue we can all relate to — the universal desire to be happy and to move past whatever is blocking us from reaching that goal.

"The use of dialogue to inquire into our experience and find deeper meaning is a time-honored technique, famously used by Socrates, the Greek teacher whose student Plato faithfully recorded his dialogues. We've taken some liberties with the Socratic method; for one thing, the seeker poses most of the questions while the wise friend offers most of the answers. Maybe these aren't the exact questions you'd ask if you were in the seeker's shoes. But see if they point to something in you that wants answering. The wise friend just might speak to your concerns.

"Happiness, it has been said, is the whole end and aim of life. But it can be elusive. We have to approach it indirectly, and with patience. Even then, we may not be sure what will be required of us. A teenager participating in an experimental program to prevent depression may have said it best: 'People have the idea that being happy means skipping through the flowers. But happy is being happy with who you are.' "