Flourishing and Virtue
'The Greek term often translated as "happiness" is eudaimonia; but many scholars prefer to translate it as something like "flourishing.".... a human being who is not plagued by sickness, poverty, oppression, loneliness or misfortune, who freely cultivates and exercises their talents, and enjoys doing this as an active participant in a pleasant community, exemplifies human flourishing. One whose life falls short in various ways does not.
[...] Today we tend to think of moral virtues solely as qualities that affect our interaction with, treatment of, and value for others: e.g. generosity, kindness, or courage. But the Greek term arete, which is often translated as "virtue," signifies, more broadly, any kind of excellence that enables a thing to perform its function. From this perspective, qualities such as, say, wisdom, curiosity, intellectual rigour, sensitivity to beauty, and discriminating aesthetic taste might be seen as moral virtues insofar as they are traits that help one achieve a higher level of fulfillment. And insofar as we fail to cultivate or exercise such qualities, we fail to exemplify human flourishing, and so fall short of what we might be.'
My thinking on happiness is very much aligned with the Greek conception.
While arete is necessary for eudaimonia, it is unfortunately not sufficient. Mere exercise of virtue does not by itself save one from misfortunes and tragedies of various sort, restricting the possibilities of flourishing available to one. It is an unsettling question: why should there be such unfairness weaved into the very moral fabric of our lives?