My question pertains to the idea of happiness being induced by a drug. If the drug--like modern anti-depressants--actually changes a person's neurochemistry such that for all intents and purposes the brain looks just like a "happy" brain, then wouldn't you consider that person happy? (Would you give a different answer for a drug like Ecstasy that alters the brain in slightly different ways than classic neurochemical happiness but still brings about a perception of happiness?) And what about the perception of happiness over the long haul? If someone is on anti-depressants for, say, fifty years, and has an over-all sense of peace, purpose, etc that they would NOT have otherwise had, have they, in fact, been happy?

The answer to your question depends on the concept of happiness. Two common assumptions about happiness are (a) that happiness is a good -- according to hedonism, the only good -- and (b) that happiness is subjective. But these two assumptions are in tension. Consider (b). Some people treat happiness as an essentially subjective condition, akin to contentment. If we accept such a view, several other claims seem to follow. It looks like happiness is a matter of being in a certain subjective state and doesn't depend upon how this state is caused -- its sources or etiology. Its likely that this sort of contentment is dependent on brain chemistry, as any mental state presumably is. For any given individual there may be multiple brain states and processes that would produce contentment, and which brain states and processes produce pleasure may vary among individuals or across species. It also seems like contenment is something the subject ought to be authoritatiave about. If so, one can't be...