Happiness is a fairly broad category of mental states, which encompasses contentment. Happiness is linked to both a set of internal subjective feelings (impossi

Happiness is a fairly broad category of mental states, which encompasses contentment. Happiness is linked to both a set of internal subjective feelings (impossible to describe, as there's no reference point. See also: the color red), and to a particular set of external behaviours which are consistent across the majority of humans (smiling, laughing, etc). If I wanted to communicate the internal subjective experience of happiness, I'd do it the same way I would the subjective experience of a color- I'd wait until I saw you experiencing it, and then I'd say "That feeling, right there. That's happiness." This is easier with colors, because I could just point to one, but it works with emotions too. Much like yourself, I tend to think of happiness as a barometer of sorts. If I'm unhappy, it means that something's wrong which needs fixing. It's not hard to see how this perspective can be reversed, though. To say that I seek to be happy and I do so by finding/building a satisfactory environment, or to say that I seek a satisfactory environment and I gauge this via happiness- in practical terms these perspectives are indistinguishable.