An Attempt at Definition
What is happiness?
To start, most people would reference well-being and contentment. For something so vague, “well-being” and “contentment” are adequate, so let us build upon this.
In valuing our state of being, there are two extremes: In [Definition 1], we define intrinsic targets (e.g. certain levels of intimate relations, social interactions, influence and material wealth) and judge ourselves to be happy when we meet them. In [Definition 2], we survey the lives of our peers, and bind our happiness to how much better off we are.
Quite clearly, the latter definition is unfavorable—if we take being happy as being above the mean (of human existence), then a great deal of people will never achieve consistent happiness. I would argue that the majority of us judge our lives against those of others. It is simply the easier route—who wants to spend time determining some arbitrary standard, and will themselves to be “happy” when they meet it?
What do we do then? For one, we can lower our expectations. If we were all content with the 25th percentile rather than the 50th, a fourth of the world would be happier (as is quite obvious). When we shift that down to the 0th percentile, Definitions 1 and 2 begin to merge, in that happiness now becomes independent of all environmental factors (i.e. autonomous).
However, it is not reasonable to believe that we can live as islands. Instead, in drifting to Definition 1, we can choose moderation in all ways (I am quite partial to the Epicurean conception of ataraxia) and choose to be happy.
This is my definition:
Having satiated the physical, happiness is a state of mind to be seized.
Quest for Happiness 
Or, happiness is an attitude and perspective towards life, no matter what other people are doing or which percentile you’re at. It seems possible, to me, for a person to be “happy” even before he has reached his goals… not because he has lowered his standards in the meantime, but simply because there is more to happiness than the achievement of something or even progress towards it.
To be happy regardless of reality is an ideal of mine. However, I don’t believe we (or most of us) are sufficiently detached from the physical to be that way.
I use “standards” in a highly flexible way, and they drop all the way to a subsistence level of nutrition/comfort etc.
I don’t think that physical detachment is the key, or even necessary, to the state we’ve described. In fact, I believe a prerequisite of happiness is that one feels whole and relatively unconflicted. Detaching the body from the mind or any part of ourselves from any other part is therefore not the best strategy, in my opinion. That leads to a very fragmented sense of self.
Hmm, you would have really loved my ISF 100B class. We talked about stuff like this all semester, especially in a modernist and postmodern context.
Or does happiness, in fact, reside in the mind at all? That you hang happiness upon physical sufficiency seems at least to indicate dependence (you mark my pun, I’m sure) on something external, a dependence your paragraph on percentiles seems to eliminate. As you reject that option, you reject the island mentality that John Donne once wrote of: but do you also reject the Athenian aristocrat’s virtue ethics of the independent man? If not, that’s a bullet you’ll have to bite.
Of course you know I believe that the Christ is a sufficient goal, one who brings us to himself to feed sacramentally on his very flesh and blood. If so, it seems to me, the achievement lies outside of us but also requires no lowered standard. This goal is neither the slave morality that internalizes happiness to such a degree that it must be called delusion, nor the master morality that professes to be independent yet calls on an army of unthinking slaves to furnish, by eliminating material want, the freedom needed to think.
What does it mean to be happy in the presence/pursuit/worship of the divine? What do you feel?
I think I’m objectively eudaimon in the worship of YHWH. Rather than telling myself stories about the external world not mattering, I hear the story of the Resurrection being inside me (and inside the bosom of the Church) as the creation groans for its physical appearance to come. Happiness, then, is redemption and completion, a bringing-up from the early naïveté of Adam and Eve to the perfect eschatological maturity of Christ and Church.
Perceiving this by faith – that is, by allegiance to the Lord of this future – I sometimes feel optimistic: I see not that we live now in the best of all possible worlds but that the Creator himself descendit de caelis into my world of ruin and death and was by us, by our need for a scapegoat, dealt the death that characterized life. Death still is, and the last enemy to be conquered is death, but in history the Resurrection of the Son of God (I haven’t read the book) changes everything. The slave in me becomes a son of God, and the master in me, which pretends to rule with all right reason, is exposed for a fraud and made obedient to the true Logos.