I disagree; to me, happiness is not to be understood a feeling; rather, it is more like a state of affairs that arises as a result of living a certain way and experiencing some kind of satisfaction as a result. But it’s not really an emotional state; it’s more of a cognitive realization that you are experiencing this state of affairs.
John Stuart Mill put it much better than me. Happiness, he said, is “not a life of rapture; but moments of such, in an existence made up of few and transitory pains, many and various pleasures, with a decided predominance of the active over the passive, and having as the foundation of the whole, not to expect more from life than it is capable of bestowing.”
Consequently, and I think this is important to our conception of what happiness is, a person can be happy whether or not he or she is experiencing pleasure, or for that matter, pain. (Much of our happiness—or maybe it’s just mine—depends on some kind of suffering, and I also know that just because I’m experiencing loads of pleasure—think of much of the early 1980s, for instance--doesn’t mean I’m happy.)
The other upshot of this conception of happiness is that a person can be mistaken about whether they are happy or not, which may seem counterintuitive at first, but which seems to me to be entirely correct.
After all, we want to be able to say a life like Sarah’s Palin’s is not a happy one, even if she’s blissful, right?