Aristotle noted at the beginning of the Nicomachean Ethics that happiness is the one thing you can choose for itself—everything else is chosen for the sake of happiness.
If Aristotle is correct, this one concept, “happiness,” is at the root of every decision we make and every action we perform, and therefore it determines whether we think our lives have meaning, whether we are going somewhere, whether we are successful, whether we are worth something (to ourselves), whether life is lived to the full, and whether life is worth living.
Inasmuch as this concept can influence our whole identity and purpose in life, it will probably influence the kinds of friends we make, the person we want to marry, the career we pursue, the clubs to which we belong, the associations with which we affiliate, and just about everything else of relevance.
If we can discover a good and comprehensive definition of happiness, then we are very likely to live a more fulfilled life in the areas of our relationships, careers, associations, lives in the workplace, in the community, in our churches, and even in culture or society. Such a fulfilled life could do considerable good — for individuals as well as the common good, for this world and even the next.
For a full discussion of the subject, read the article here.