Fredrickson’s ten positive emotions—joy, gratitude, serenity, interest, hope, pride, amusement, inspiration, awe, and love—on your phone, computer, or office wall.

But the successful seller must feel some commitment that his product offers mankind as much altruistic benefit as it yields the seller in money.

More than two thousand years ago Aristotle used a term that is still in wide use in psychology today: eudaimonia. It refers to a state of deep wellbeing in which a person feels that their life has meaning and purpose. It is often contrasted with hedonia (the origin of the word hedonism), which refers to the fleeting happiness of various pleasures. To put it another way, if hedonic happiness is what you mean when you say you’re having a good

time, then eudaimonic happiness is what we mean when we say life is good. It is a sense that, outside of this moment, regardless of how pleasurable or miserable it is, your life is worth something, and valuable to you. It is the kind of well-being that can endure through both the ups and the downs.

Some psychologists object to the word “happiness” because it can mean anything from a temporary pleasure to an almost mythical sense of eudaimonic purpose that few in reality manage to reach. So in lieu of happiness, more nuanced terms like “well-being,” “wellness,” “thriving,” and “flourishing” have become common in the popular psychological literature. We use those terms in this book. Marc is particularly fond of the terms thriving and flourishing because they refer to an active and constant state of becoming, rather than just a mood. But we still use “happiness” at times for the simple reason that this is how people talk about their lives. Nobody says, “How’s your human flourishing?” We say, “Are you happy?” And it’s how, in casual conversation, we both find ourselves talking about our research as well.

This might all sound quite intuitive, but there is a very powerful yet simple message nestled in these findings: the frequency and the quality of our contact with other people are two major predictors of happiness.