(This was my response to the Office of National Statistics' "What is well-being?" question. It's an issue I've been trying to understand for many years, but have only really succeeded in working out what happiness is not. Hopefully the thought process will take more than the 3,000 characters that the ONS site allows. Or maybe it requires far, far fewer.)
Health, relationships, job, money - happiness is all of these things, and yet at the same time it is none of them. Happiness is not a "thing", though. Instead, it may be helpful to think it using 3 levels:
1. "Traditional" ideas of what happiness is depend largely on the idea that it results from "good" things happening *to* someone. For instance, consuming food, and being able to consume food (via money), being cured, watching films, etc. This is a fairly basic form of happiness, but is short-lived and utterly dependent on external forces.
2. "Emerging" ideas of happiness take creativity into account - i.e. we must give something back to the world to be happy. "Job satisfaction" (an ugly term for daily passion) is an example of this, as are children to some extent (the ultimate act of creation). Creativity acts on the creator as much as what is created.
Both these models, though, assume that happiness "belongs" to the self - the individual - and that it arises as a *result* of the self interacting with the "outside" world - either consuming it or creating it. But happiness is not a simple rational emotion, any more than depression is. It exists in the mind, but cannot be said to be a mental process - rather, it is a state of *being* which uses the mind as a conduit.
We can then define a new level for happiness:
3. Happiness as "integration" - this begins to move away from happiness as an "end result", and more towards an inherent part of existence, something which feeds back into what we do and becomes who we are.
Maybe this is similar to the sound that comes out of an orchestra: each chord is a "result" in that it involves a co-ordination, not just across musicians, but between each musician and their instrument, and between each instrument and its environment. But each chord is not anything in itself, but set in the context of all other chords, and which simultaneously sets the context for all other chords too.
What is happiness at this stage? It can be said to be intrinsically related to our relations, just as a chord cannot sound without an orchestra, but an orchestra with no sound is not an orchestra.
This is vital in understanding the importance that relationships have with happiness - the link must be bi-directional. The two support each other, and create each other. This is where "happiness" can truly be defined as "well-being" - happiness is no longer an end in itself, but something which creates in order to create, and in order to create itself. It becomes an act of being spread across the self and others so that the "self" boundary is blurred. This is why family, community and a relationship with nature are important.
Finally, but fundamentally, happiness is also about the self's relationship with *itself*, an internal, self-supporting form of well-being. This is the most difficult to measure, as it is subjective by definition.
To understand this requires wisdom and subtlety. But it is also obvious if looked for.