You're pretty clearly right. What's going on around us matters for our happiness, and though how we look at things makes a difference, it's not all. There may be some people (a fully enlightened being such as the Buddha supposedly was, perhaps?) who are able to maintain their equanimity in all circumstances, but for the rest of us, this would be a superhuman achievement. Moreover, it's not entirely obvious that it would be desirable to have that kind of detachment.
That said, there's a point to the saying that no one can make you happy. Making others responsible for one's own happiness is not a mark of wisdom, and not likely to succeed.
It's a nice question, and one that' s been discussed before in various versions. You've put particular emphasis on the idea that without negative emotions, we couldn't really be happy.
Let's suppose you're right. As your own way of putting things suggests, it doesn't follow that there couldn't be such a thing as eternal happiness. The reason is that the kind of happiness that's at issue isn't best thought of as an emotion or mood but as some more global feature of our lives. In fact, your own point is that negative states can be part of, well, our happiness.
We could also spend a bit of time on whether "negative states" that we enjoy (the frisson of "horror" we pay good money for at the movies, for example) really are negative states. But let that pass. I think the partisan of eternal life would probably object to being tied to the word "happiness." Some talk, for example, of "eternal bliss." But whatever state that's meant to pick out, it may not be quite the same as the one we describe as "happiness." This isn't to disparage happiness; it's just to say that there might be more than one kind of condition that we'd want to think about if we were thinking seriously about eternal life.
And while we're at it, we might want to query the word "eternal." Should we think of eternal life as unending? Or as outside time altogether? If eternal life is atemporal life, then our usual ways of thinking about what it is to be happy may not be up to the task.
Of course, the idea of life outside time might seem too paradoxical to take seriously, though the idea that God is outside time has a long history in theological thought. But the larger point here may allow us to dance around the question: if there is such a thing as eternal life, it seems a reasonable bet that we're not in a very good position to imagine what it's like.
Needless to say, the fact that we have trouble imagining something isn't a reason for believing that it's true. But the fact that we have trouble imagining something isn't always a good guide to whether it's possible either.
A couple of further points. The first is that I'm not particularly inclined to believe that something like eternal happiness awaits us, but that's not because I think the idea is incoherent. The second is a bibliographic note: there is a well-known paper by Bernard Williams, in which he argues, roughly, that anything that could count as one's own endless life would be intolerably boring, and that any sort of endless "life" that escaped this fate wouldn't be one's own. (Williams means to raise a problem about personal identity here; you can chase down the essay, which is called "The Makropoulos Case: Reflections on the Tedium of Immortality." It's in his Problems of the Self, Cambridge University Press, 1973.) I find William's arguments singularly unconvincing, but you might feel differently. John Martin Fischer offers a reply called "Why Immortality is Not So Bad," in International Journal of Philosophical Studies, 1994 pp. 257-270. And you can read an interesting discussion by Tim Chappell here.
Most philosophers (including several you have no doubt heard of, such as Plato and Aristotle) who have thought that happiness was the appropriate goal of a good life have not understood the goal they had in mind as a purely subjective state, so I would encourage you and your friend to consider the possibility that it is not simply feeling happy that matters, but actually being a certain way.
Consider the case of a drug addict who is provided a lifetime supply of his or her drug of choice. If you wish, imagine miraculously finding a way to ensure that the addict's life and physical health would in no way be threatened--his or her expected life span would not be shortened, nor would the lifelong addiction threaten the addict's physical health in any way. In short, the addict could go through life high as a kite with all other necessities provided with indemnity against any of the usual deliterious affects of drug-addiction.
The case I am asking you to imagine is probably impossible on various grounds, for it is plainly impossible to remove all of the negative effects of going around high all the time, but anyway consider at least some period of time during which the addict is high all the time and well protected against the usual bad effects associated with drug use. Is that person happy?
In the purely subjective sense of happy, I think we have to say that such a person would be happy--maybe even supremely so. But if this subjective sense were all that mattered, why do we recoil from wishing for ourselves such a life? Why is it that we find ourselves preferring lives in which our entertainments, engagements, and activities include much more than simply sitting in a delighted stupor all the time? If such a person is really more happy as a result of the constant subjective happiness he or she feels, why would we prefer our admittedly less happy (subjectively) lives to their's?
This sort of example seems to me to show either that "happiness" is not actually what we have in mind as an ultimate goal, or else that the correct understanding of what it means to be truly happy must include both an objective as well as a subjective element. I do not wish to suggest that a subjective sense of happiness is unimportant or irrelevant. Rather, I am proposing that this is not by itself enough--that some objective conditions that wwe regard as choiceworthy must also be included in the correct and fully adequate sense of what our life goal should be. We wish to lead lives that sensible people would wish to emulate. That is why some philosophers and scholars have suggested that the sense of "happiness" we should be considering for such questions ought to be something like "well-being" or perhaps "human flourishing," both of which seem to require subjective and objective success.
I hope this helps!
I wonder just how widely accepted this is. I suspect that most people, including panelists here, would agree that just because someone thinks they've been harmed, it doesn't mean that they actually were. In fact, it's perfectly possible that something someone takes to have harmed them actually did them good. (You might think your boss would be upset if he knew that you stood up to some obstreperous client. I know that he'd actually be pleased; he's been looking for an excuse to "fire" this client, you've provided it, and because I tell him what you did, you'll be in for a bonus at year's end.)
There are a couple of cases that might seem to support the equation of thinking one has been harmed with actually being harmed, but I'm not sure they're what you had in mind. First, suppose I think I'm in pain. It's been widely held that I can't be mistaken about this. I might be mistaken about whether the pain signals some sort of organic damage, but if I think I have a headache, it's odd to say that I don't -- even if it's all "in my head," if you get my drift. But that's a special kind of case.
Another sort of case might be when you've done something that upsets me. If my distress is unreasonable, I doubt we'd be inclined to say that you harmed me. If what you did could be expected to distress most people, we might count this as harm. For example: suppose you've mocked me in front of people whose opinion I might reasonably care about. The fact that I care is part of why I take myself to have been harmed. (Harm to reputation is a kind of harm.) If I were more thick-skinned, there would be no harm. But it might be unreasonable to expect me not to care.
I'm not sure how much that helps. As for objective ways of defining "harm," I don't have a lot to offer that's terribly informative, except to say that if I do something to you that interferes with your normal functioning, physically, socially, economically, emotionally... we might reasonably count that as harm. But the mere fact that I take myself to have been harmed doesn't settle the matter.
On this topic, I have always been intrigued by Simone de Beauvoir's comments in the introduction to The Second Sex. She says:
But we do not confuse the idea of private interest with that ofhappiness, although that is another common point of view. Are not womenof the harem more happy than women voters? Is not the housekeeperhappier than the working-woman? It is not too clear just what the word happyreally means and still less what true values it may mask. There is nopossibility of measuring the happiness of others, and it is always easyto describe as happy the situation in which one wishes to place them.
In particular those who are condemned to stagnation are oftenpronounced happy on the pretext that happiness consists in being atrest. This notion we reject, for our perspective is that ofexistentialist ethics. Every subject plays his part as suchspecifically through exploits or projects that serve as a mode oftranscendence; he achieves liberty only through a continual reachingout towards other liberties. There is no justification for presentexistence other than its expansion into an indefinitely open future.Every time transcendence falls back into immanence, stagnation, thereis a degradation of existence into the ‘en-sois’– the brutish life of subjection to given conditions – and of libertyinto constraint and contingence. This downfall represents a moral faultif the subject consents to it; if it is inflicted upon him, it spellsfrustration and oppression. In both cases it is an absolute evil. Everyindividual concerned to justify his existence feels that his existenceinvolves an undefined need to transcend himself, to engage in freelychosen projects.
What this suggests to me is that happiness may be at odds with freedom or transcendence (these latter aren't necessarily the same, of course). The idea seems to be that genuine freedom (and transcendence) are difficult and one is not likely to be happy if one pursues them. And yet, they are more valuable than happiness. (And more valuable than the experience of being free or of transcendence.)
Others are likely to say that virtue is more valuable than happiness, and these two are often in conflict. Many philosophers have tried to argue that there is a necessary connection between virtue and happiness, but it is a hard case to make. For example, we often make commitments to others and it would seem that we have a duty to fulfill those commitments, even if doing so would make us worse off -- and even positively unhappy -- in both the short and long term.
I'm inclined to think that happiness, at least according to most interpretations, isn't the most important or valuable thing. Freedom and virtue are more important to me. Moreover, I'm also inclined to think that actively pursuing happiness isn't the best way to achieve it. This is connected to the idea of "flow" Eddy mentions. Happiness comes when you are engaged in meaningful activity that is well-suited to your abilities (it challenges you, but not too much); it's a byproduct of activity, not the goal of activity.
I think you hit the nail on the head at the end where you acknowledge that an excellent way of being happy is not to try to be happy, but just to do what you find fulfilling. Once you start asking questions about what makes you happy it is difficult to feel content with any particular state of affairs, especially if you see happiness as a reward in the future for hard work in the present. I would get out of the library and spend more time doing things you enjoy doing right now, and that will make your academic work much more productive and enjoyable.
The ancient Greeks are among those who are often said to claim that happiness is the "ultimate aim" of human life, but one reason scholars have insisted that this is misleading is indicated to some degree in the question here. The actual word in Greek that is usually translated as "happiness" is eudaimonia, and scholars now argue that we should understand this not as a subjective experience, but as an objective state of the person--scholars have suggested "well-being" or "human flourishing" as more accurate translations. In other words, for the Greeks, the ultimate aim is something more like being healthy than like feeling happy. Just as the experience of pain may sometimes be required for a healthy life, it may also be required for one to live a eudaimÇn life, so we should not suppose that what these philosophers endorse is the opposite of pain, or the (mere) pursuit of pleasure or subjective satisfaction. Of course, one would expect that a human being living in a way we would describe as "flourishing" would also enjoy a substantial degree of subjective satisfaction. But a drug addict given unlimited access to his favorite drug might experience equal--perhaps even greater!--levels of subjective satisfaction than people living well might experience, for full human lives also include pain, grief, and other subjective "negatives." To put it another way, to live the best possible human life, one must (at the right times and in the right ways, and to the right degrees, etc.) sometimes experience such subjective negatives. Pain felt when it is right and appropriate to feel pain is a part of the eudaimÇn life. Those who are incapable (or too stoned!) to feel grief when grief is appropriate do not lead enviable lives, and we would not wish such conditions on ourselves, our friends, or our children.
If we frame the question this way, "What is it for a human being to do well, to live a life that is the sort we would regard as choiceworthy and would wish for ourselves, our friends, or children?" then I think it will be clearer that we would not necessarily think of "happiness" as our main aim, unless we have a very enriched sense of the word in mind. Lying on a warm beach makes me happy--so does playing with kittens--but I wouldn't count such things as prividing a main aim for human life.
At any rate, I am thus sympathetic with the questioner who wants to know what's supposed to be so great about happiness. I would propose framing the question I gave above, and whatever is the answer to that question is what we may reasonably regard as our main aim.