Happiness is the one goal almost everyone shares, yet almost no one can easily define. People pursue it through wealth, through relationships, through achievement, through faith, through pleasure, and through the renunciation of pleasure. Psychologists measure it on Likert scales and track it with experience sampling applications; economists incorporate it into welfare functions; neuroscientists locate its correlates in dopamine systems and prefrontal cortex activity. And yet philosophers from Aristotle to Kant to the Buddha have insisted that the most important questions about happiness -- what it actually is, whether it is the right thing to aim at, and how it relates to virtue and meaning -- cannot be settled by empirical measurement alone.
The central distinction in philosophical discussions of happiness is between hedonism and eudaimonism. Hedonism, in its simplest form, identifies happiness with pleasure: a happy life is one that contains more pleasure than pain. Eudaimonism -- from the Greek eudaimonia, which Aristotle used and which defies clean translation -- identifies happiness with flourishing: a life that is going well, that exercises one's distinctively human capacities, and that is lived in accordance with virtue and in the company of genuine friends. The two accounts can converge on specific recommendations, but their underlying logics are different enough that they sometimes pull in opposite directions. The hedonist's most pleasurable choice might be the eudaimonist's worst.
This is not merely an abstract dispute. Modern positive psychology, which emerged as a research program under Martin Seligman in the late 1990s, has produced substantial empirical evidence about what actually makes human lives go well -- evidence that bears interestingly on the ancient philosophical debate. The convergences between empirical findings and philosophical intuitions are sometimes striking; the divergences are equally instructive. And the question of how to live well -- not just how to feel good, but how to inhabit a life that has genuine worth -- remains as urgent as it has ever been.
"Happiness is the meaning and the purpose of life, the whole aim and end of human existence." -- Aristotle, Nicomachean Ethics (c. 350 BCE)
Key Definitions
Eudaimonia: Aristotle's term for human flourishing or living well -- the active exercise of the soul's faculties in accordance with virtue over a complete life. Distinguished from mere subjective pleasure by its requirement for both internal virtue and external conditions.
Hedonism: The view that happiness consists in pleasure and the absence of pain. On hedonistic accounts, the good life maximizes pleasurable experience. Epicurean hedonism identifies the most reliable pleasures with simple living, philosophical friendship, and freedom from anxiety.
Hedonic adaptation: The psychological phenomenon whereby humans return relatively rapidly to a stable baseline of subjective wellbeing after both positive and negative events -- the mechanism by which lottery winners are not, in the long run, significantly happier than before, and paraplegics are not as permanently unhappy as observers expect.
Ataraxia: Epicurus's term for tranquility or freedom from anxiety -- the goal of Epicurean philosophy, achieved through simple living, philosophical reflection, and freedom from fear of death and divine punishment.
Flow: Mihaly Csikszentmihalyi's concept for the state of complete absorption in a challenging activity at or just beyond the edge of one's current capabilities -- characterized by loss of self-consciousness, intrinsic motivation, and reported high wellbeing.
Hedonism and Its Variants
Epicurus and the Art of Pleasure
Epicurus (341 -- 270 BCE) is often misrepresented as advocating sensual indulgence, when his actual teaching was almost its opposite. Epicurus argued that the most reliable and sustainable pleasures are katastematic rather than kinetic -- pleasures of stable, undisturbed contentment rather than pleasures of active sensory stimulation. The highest pleasure is ataraxia, the tranquility of a mind free from anxiety, fear, and unfulfilled desire.
Epicurus divided desires into natural and necessary (food, shelter, friendship), natural and unnecessary (gourmet food, luxury goods), and unnatural and unnecessary (fame, power, political ambition). Natural and necessary desires are easily satisfied and produce reliable happiness when met; unnecessary desires produce anxiety when unfulfilled and rapid habituation when fulfilled, leaving one always wanting more. The wise person concentrates on the first category and minimizes dependence on the second and third.
The most important philosophical contribution of Epicurus was his treatment of the fear of death. "Death is nothing to us," he argued, "because when we exist, death is not present, and when death is present, then we do not exist." The Epicurean therapy was directed at demonstrating that the badness of death cannot consist in what happens to the person who has died -- since there is no such person to be harmed -- and therefore that death is not something that any rational person need fear. Whether this argument succeeds has been debated extensively, most notably by Thomas Nagel in 'Death' (1970), who argued that death can be a harm by depriving a person of the goods they would otherwise have enjoyed.
Jeremy Bentham's Felicific Calculus
Bentham's hedonic calculus, discussed in utilitarian ethics, represents the most systematic attempt to operationalize hedonism as a decision procedure. Bentham was explicit that "pushpin is as good as poetry" -- that no pleasure is intrinsically superior to another, and that the moral and policy question is purely quantitative: which option produces the greatest net pleasure?
John Stuart Mill's revision, introducing qualitative distinctions among pleasures, represents a significant departure from pure hedonism: if intellectual pleasure is intrinsically superior in kind to sensory pleasure, then the criterion of rightness cannot be purely experiential. Derek Parfit, in 'Reasons and Persons' (1984), pressed Robert Nozick's experience machine objection to hedonism: if happiness were purely a matter of subjective experience, we should be indifferent between a life of genuine achievement and a simulated life of equivalent subjective quality. Since most people are not indifferent, and since their preference for real over simulated goods seems rational rather than irrational, hedonism appears to leave out something that matters.
Aristotle and Eudaimonia
The Function Argument
Aristotle develops his account of eudaimonia in the 'Nicomachean Ethics' through the function argument: everything that has a function (ergon) has a characteristic excellence, and the good for that kind of thing is to perform its function excellently. What is the function of a human being? Not mere life, since plants live; not sentient experience, since animals share this; but rational activity -- the exercise of the soul's faculties in accordance with reason. The good for a human being is the active exercise of these faculties in accordance with virtue.
This makes eudaimonia an activity rather than a state. You cannot be flourishing while you are asleep; flourishing is something you do, not something you have or undergo. And it is evaluated over a whole life: the person who lives well for twenty years and then spends the last decade of their life in degradation or misery has not, on Aristotle's account, lived a flourishing life, however good the first twenty years were. This has been criticized as counterintuitive by philosophers including Shelly Kagan and by common sense: surely the twenty good years were good years regardless of what came after?
Aristotle also requires external goods for full eudaimonia -- health, moderate wealth, friendship, and reasonable good fortune. This distinguishes his account from both Stoicism (which holds that virtue alone is sufficient for happiness) and Kantianism (which holds that the only unconditional good is the good will, and that happiness as such has no moral status). For Aristotle, the person of excellent character who is struck by terrible misfortune -- who loses their children, friends, and health -- cannot fully flourish. "It is impossible, or not easy, to do noble acts without the proper equipment."
Friendship as Constitutive of Flourishing
One of the most distinctive features of Aristotle's ethics is the central role of deep friendship (philia) in eudaimonia. Aristotle distinguishes three types of friendship: friendships of utility (we are friends because we are useful to each other), friendships of pleasure (we are friends because we enjoy each other's company), and friendships of virtue (we are friends because we genuinely admire each other's character and wish each other well for our own sakes). Only the third type constitutes the deep friendship that is a constitutive part of the good life.
This is philosophically significant because it means that eudaimonia is inherently relational: you cannot flourish in isolation. The Stoic sage can maintain his equanimity in a dungeon; the Aristotelian person of excellent character cannot fully flourish without relationships of genuine mutual recognition and care. Modern research on wellbeing strongly confirms the Aristotelian insight: Robert Waldinger's Harvard Study of Adult Development, which tracked participants for over eighty years, found that the quality of close relationships was the single strongest predictor of health and wellbeing in old age.
Kantian Ethics and the Relationship to Happiness
The Good Will and Its Limits
Kant's ethical framework places happiness in a subordinate position that distinguishes it sharply from both hedonism and eudaimonism. For Kant, the only unconditional good is the good will -- the will that acts from duty, motivated by respect for the moral law rather than by inclination or the pursuit of happiness. Happiness has conditional value: it is good when the agent who possesses it is also morally worthy, but the pursuit of happiness at the expense of duty is not merely imprudent but morally wrong.
This creates a complex relationship between morality and happiness in Kantian ethics. Kant does not claim that happiness is unimportant or that we should not pursue it. He argues in the 'Groundwork' and the 'Critique of Pure Reason' that there is a 'highest good' (summum bonum) that consists in the conjunction of virtue and happiness -- the state in which virtuous people are as happy as their virtue merits. But this highest good cannot be achieved in the natural world by human effort alone; its possibility requires the postulates of practical reason: the existence of God (who can ensure that virtue and happiness are ultimately aligned) and the immortality of the soul (which provides the infinite time required for the moral perfection that virtue demands).
Duty and the Question of Motivation
One of the persistent challenges for Kantian ethics is the relationship between moral duty and personal motivation. Kant holds that the person who does the right thing from inclination -- who acts kindly because they feel warm affection for others -- has no more moral worth than the person who does nothing at all. Moral worth attaches only to actions done from duty, motivated by respect for the moral law. This makes the naturally sympathetic, warm-hearted person morally equivalent to the person who overcomes cold calculation to do their duty.
Bernard Williams found this aspect of Kantian ethics deeply unattractive. A person who deliberates about whether to save their drowning spouse in terms of whether it accords with the categorical imperative has, Williams argued, "one thought too many." The appropriate motivation for saving your spouse is simply that they are your spouse -- not that a principle of universal law requires it. The Kantian framework seems to eliminate the significance of personal relationships and particular attachments in a way that conflicts with our deepest sense of what matters.
Buddhist and Eastern Perspectives
The Buddhist framework approaches happiness through the lens of the four noble truths: the truth of dukkha (the pervasive unsatisfactoriness of conditioned existence), the truth of its arising (from craving and attachment), the truth of its cessation, and the truth of the path to cessation. Genuine happiness, on the Buddhist account, requires not the accumulation of pleasurable experience but the transformation of the relationship to experience itself.
The Tibetan Buddhist concept of sukha -- often translated as happiness or well-being -- is understood as a deep equanimity that arises from insight into the impermanent and interdependent nature of all phenomena, not as a hedonic state. Matthieu Ricard, a French monk and biochemist, has been informally described as the world's happiest person based on fMRI measurements of gamma-wave activity during meditation; his book 'Happiness' (2003) presents the Buddhist account of wellbeing as a trainable mental skill.
Importantly, the Buddhist dissolution of the self as a condition for happiness represents a structural difference from Western accounts, all of which presuppose a self whose wellbeing is to be promoted. The Buddhist critique is that this very presupposition -- the belief in a fixed, permanent self -- is a fundamental source of suffering.
What Psychology and Philosophy Agree On
The convergences between philosophical accounts of happiness and contemporary empirical findings are notable. Both Aristotelian ethics and positive psychology research emphasize the importance of meaningful activity (not just pleasurable activity), deep relationships, and the engagement of one's capacities. Both the Stoics and cognitive therapists point to the role of cognitive appraisal in generating emotional states, and to the possibility of changing those states by changing the appraisals. Both Epicurus and research on hedonic adaptation suggest that stability and contentment are more reliably achieved through simple pleasures and freedom from anxiety than through the pursuit of excitement and novel stimulation.
The deepest remaining philosophical question is normative: not just what makes people feel happy, but what makes a life genuinely good. Ed Diener's research identifies subjective wellbeing through self-report measures; but whether people are the best judges of whether their lives are going well -- whether authentic deep satisfaction tracks genuine flourishing -- remains an open question that empirical research cannot by itself answer.
References
- Aristotle. (c. 350 BCE). Nicomachean Ethics. Trans. Terence Irwin. Hackett, 1999.
- Epicurus. (c. 300 BCE). Letter to Menoeceus. In J. Cooper (Ed.), Complete Works. Hackett, 1998.
- Kant, I. (1785). Groundwork of the Metaphysics of Morals. Trans. M. Gregor. Cambridge University Press, 1997.
- Mill, J. S. (1863). Utilitarianism. Parker, Son, and Bourn.
- Parfit, D. (1984). Reasons and Persons. Oxford University Press.
- Nozick, R. (1974). Anarchy, State, and Utopia. Basic Books.
- Seligman, M. E. P. (2011). Flourish. Free Press.
- Csikszentmihalyi, M. (1990). Flow: The Psychology of Optimal Experience. Harper & Row.
- Ricard, M. (2003). Happiness: A Guide to Developing Life's Most Important Skill. Little, Brown.
- Kahneman, D., & Deaton, A. (2010). High income improves evaluation of life but not emotional well-being. PNAS, 107(38), 16489-16493.
- Nussbaum, M. C. (2001). Upheavals of Thought: The Intelligence of Emotions. Cambridge University Press.
- Waldinger, R., & Schulz, M. (2023). The Good Life: Lessons from the World's Longest Scientific Study of Happiness. Simon & Schuster.
Frequently Asked Questions
What is the difference between hedonism and eudaimonia?
Hedonism holds that happiness consists in pleasure and the absence of pain. The good life, on a hedonist account, is the life that contains the most pleasure and the least suffering. The Epicurean tradition, often misread as advocating sensual indulgence, actually argued for a refined hedonism in which the most reliable path to pleasure was simple living, philosophical friendship, and freedom from anxiety about death and the gods -- ataraxia, tranquility.Eudaimonia, often translated as 'happiness' but more accurately rendered as 'flourishing' or 'living well,' is Aristotle's central ethical concept. For Aristotle, eudaimonia is not a feeling or a mental state but an activity -- the activity of living and doing well according to the functions and excellences characteristic of human beings. A human being flourishes by exercising the capacities that are distinctively human: rational activity, practical wisdom, the cultivation of character, meaningful work, and deep friendship.The difference is practically significant. A life of moderate pleasure achieved through passive consumption might score high on a hedonistic measure but low on a eudaimonic one. Conversely, a life of demanding engagement -- parenting, creative work, political service -- might involve substantial discomfort and difficulty while constituting, on an Aristotelian account, a deeply flourishing life. Positive psychologists including Martin Seligman have operationalized both dimensions, distinguishing 'positive emotion' (hedonism) from 'engagement,' 'relationships,' 'meaning,' and 'accomplishment' (eudaimonic dimensions) in his PERMA model.
What does Aristotle say makes a good life?
Aristotle's account of the good life is developed primarily in the 'Nicomachean Ethics.' He begins from the observation that everything we do, we do for some end or purpose, and that there must be some ultimate end for which we do everything else -- not itself a means to anything further. This ultimate end is eudaimonia, often translated as happiness or flourishing.What does eudaimonia consist in? Aristotle argues through the function argument: just as a good knife is one that performs the function of a knife excellently, a good human life is one that performs the function of a human being excellently. The function of a human being, as a rational animal, is the active exercise of the soul in accordance with virtue -- specifically, with practical wisdom (phronesis), the intellectual virtue that enables right action.Crucially, Aristotle argues that eudaimonia requires external goods as well as internal virtue. A person who is severely poor, friendless, ugly, or bereaved of children cannot fully flourish, no matter how virtuous they are. This distinguishes Aristotle's account from Stoic virtue ethics, which holds that virtue alone is sufficient for the good life. Aristotle also requires that flourishing be evaluated over a whole life -- single episodes of pleasure or success do not constitute flourishing, which is a lifetime achievement, the reason Solon reportedly told Croesus that no one should be called happy until they are dead.Friendship (philia) occupies an unusually prominent place in Aristotle's ethics. Deep friendship -- between people who value each other for their character, not merely for mutual usefulness or pleasure -- is not a means to happiness but a constitutive part of it.
What does positive psychology research say about happiness?
Positive psychology, the scientific study of wellbeing and flourishing, was formally launched as a research program by Martin Seligman in his 1998 presidential address to the American Psychological Association. The field has produced a large body of empirical findings about the correlates and causes of subjective wellbeing.Among the most robust findings: social relationships are the strongest predictor of subjective wellbeing across cultures; hedonic adaptation means that positive events (promotions, windfalls, even winning the lottery) produce shorter-lasting wellbeing improvements than people predict; autonomy -- the sense of choosing one's own activities -- is a strong and consistent predictor of wellbeing; flow states (Mihaly Csikszentmihalyi's term for the absorption in challenging activities at the edge of one's capabilities) are associated with high wellbeing even when the activity is effortful; and money has diminishing returns on happiness beyond the point where basic needs and security are met, though Daniel Kahneman and Matthew Killingsworth's research has suggested that the relationship continues at higher income levels than the famous earlier '$75,000' ceiling suggested.Ed Diener's life satisfaction research and Seligman's PERMA model (positive emotion, engagement, relationships, meaning, accomplishment) both capture both hedonic and eudaimonic dimensions of wellbeing, broadly corresponding to the philosophical distinction between hedonism and Aristotelian flourishing. The convergence between ancient philosophical accounts and contemporary empirical findings is striking.
What is the Buddhist view of happiness and how does it differ from Western accounts?
Buddhist accounts of happiness center on the concept of dukkha -- often translated as suffering, but more accurately as a pervasive unsatisfactoriness or dis-ease that characterizes ordinary experience. The Buddha's first noble truth is that life as ordinarily lived is characterized by dukkha. The second noble truth is that dukkha arises from tanha -- craving, attachment, and aversion. The third noble truth is that liberation from dukkha is possible. The fourth noble truth is that the path to liberation is the eightfold path.The distinctive feature of Buddhist happiness theory is that genuine wellbeing requires the dissolution of the illusion of a fixed, permanent self (anatta, or non-self). On the Buddhist view, much of our suffering arises from defending and promoting a self that is itself a construction, a narrative overlay on a flow of impermanent processes. Genuine equanimity -- not mere resignation but a positive lucidity -- arises when this construction is seen through.This contrasts with Western accounts in an interesting way. Aristotle's eudaimonia is the flourishing of a stable self with developed character. Stoic equanimity is achieved by an integrated self who has correctly classified goods. Even hedonism assumes a self whose pleasure is to be maximized. The Buddhist dissolution of the self as a condition for happiness is structurally different from all of these, though contemporary mindfulness practice -- drawing heavily on Buddhist meditation techniques -- has been integrated into psychological therapies (MBSR, MBCT) with substantial evidence for effectiveness in reducing suffering and increasing wellbeing.
Can money buy happiness?
The relationship between income and subjective wellbeing has been one of the most studied and contested questions in happiness research. The influential early finding by Richard Easterlin in the 1970s -- the Easterlin Paradox -- held that within a country, wealthier people were happier than poorer ones, but that as countries grew wealthier over time, average happiness did not increase proportionally. This suggested that relative position within a social hierarchy, not absolute income, was what mattered.Daniel Kahneman and Angus Deaton published a widely cited 2010 paper in 'PNAS' finding that emotional wellbeing (day-to-day positive affect) plateaued at approximately \(75,000 annual income in the United States, while life satisfaction (overall evaluation of one's life) continued to rise with income above that threshold. The \)75,000 figure became widely cited, though it applied specifically to emotional wellbeing and to the American context in 2010.Matthew Killingsworth's 2021 research using experience sampling (tracking real-time emotional states via smartphone) found that happiness continued to rise with income well above $75,000, contradicting the earlier finding. Kahneman and Killingsworth subsequently published a joint analysis in 2023 reconciling the findings: for most people, happiness rises monotonically with income, but for a minority of 'unhappy' people, the plateau effect is real -- suggesting that money can improve happiness, but only up to the point where it fails to address the source of unhappiness.Philosophically, the findings are broadly consistent with accounts that distinguish between the removal of suffering (addressed by meeting basic needs and achieving security) and positive flourishing (which requires more than material comfort).