Aristotle’s Nicomachean Ethics stands as one of the most influential and enduring works in the history of moral philosophy. Written in the 4th century BCE, this treatise presents a systematic investigation into the nature of human good, virtue, and the conditions necessary for human flourishing (eudaimonia). Unlike many modern ethical theories that focus primarily on rules, duties, or consequences, Aristotle’s approach is fundamentally concerned with character and the kind of life worth living; the central arguments and concepts of the Nicomachean Ethics analyse Aristotle’s virtue ethics framework, his conception of human flourishing, and the continuing relevance of his insights for contemporary moral philosophy.
The Nicomachean Ethics represents Aristotle’s mature reflection on questions that had occupied Greek philosophers since Socrates: What constitutes the good life? How should human beings live? What is the relationship between virtue and happiness? Aristotle’s answers to these questions are both systematic and nuanced, grounding ethics in human nature while acknowledging the complexity of moral life. His approach differs markedly from both Platonic idealism and later deontological or consequentialist frameworks, offering instead what we now recognise as virtue ethics, a theory focused on moral character rather than moral rules or outcomes.
The Function Argument and Human Flourishing
Aristotle begins his ethical inquiry with the observation that every action and choice seems to aim at some good, leading to his famous assertion that there must be some highest good that we pursue for its own sake rather than as a means to something else. This highest good, he argues, is eudaimonia, often translated as happiness but better understood as human flourishing or living well. The concept of eudaimonia is central to Aristotelian ethics and represents not a momentary feeling of pleasure or satisfaction, but a complete and flourishing human life. To understand what human flourishing consists in, Aristotle employs what scholars call the “function argument.” Just as the good of any object or natural being depends on how well it performs its characteristic function, a knife cuts well, an eye sees clearly, so too must human good depend on how well human beings perform their characteristic function. But what is the distinctive function of human beings? Aristotle argues that it cannot be mere life (which we share with plants) or perception (which we share with animals), but must be the activity of the rational soul in accordance with virtue.
This argument is both ingenious and controversial. It grounds ethics in human nature while avoiding crude naturalistic fallacies. For Aristotle, human beings are essentially rational animals, and our good consists in the excellent performance of our rational capacities. This includes not only theoretical reasoning but also practical reasoning—the capacity to deliberate well about how to live and act. The function argument thus establishes that human flourishing involves the actualisation of our rational capacities in excellent ways, which is to say, virtuously. Critics have questioned whether human beings have a single, determinate function analogous to that of objects or biological organs. Contemporary philosophers like Philippa Foot and Rosalind Hursthouse have defended neo-Aristotelian approaches that ground virtue in human nature without relying heavily on the function argument. Nevertheless, Aristotle’s insight that ethics must be grounded in an understanding of human nature remains influential and compelling.
The Doctrine of the Mean and Moral Virtue
Perhaps the most famous aspect of Aristotle’s ethics is his doctrine of the mean, which provides his account of moral virtue. Aristotle distinguishes between two types of virtue: intellectual virtues (excellences of mind) and moral virtues (excellences of character). Moral virtues are acquired through habituation and practice, and they concern our emotions, desires, and actions in social situations. According to the doctrine of the mean, moral virtue is a disposition to choose the intermediate course between extremes of excess and deficiency. Courage, for instance, is the mean between cowardice (deficiency of confidence in the face of danger) and recklessness (excess of confidence). Generosity lies between stinginess and profligacy. Aristotle emphasises that the mean is not a mathematical average but must be determined relative to circumstances and individuals—what counts as generous giving depends on one’s resources and the needs of the situation. This doctrine captures important insights about moral psychology and practical wisdom. It recognises that virtue often involves finding the right balance in complex situations rather than following simple rules. It also acknowledges that moral development requires practice and habituation; we become virtuous by acting virtuously, just as we become skilled musicians by practising music. The doctrine of the mean thus provides both a structural account of virtue and a practical guide for moral development. However, the doctrine also faces significant challenges. Some virtues seem to resist analysis in terms of means; honesty, for instance, does not appear to be a mean between truth-telling and lying. Additionally, the doctrine may seem to counsel moderation in all things, potentially justifying moral mediocrity. Aristotle addresses some of these concerns by noting that some actions and emotions are inherently wrong and admit of no mean, and by emphasising that the mean represents excellence rather than mere moderation.
Practical Wisdom and Moral Knowledge
Central to Aristotle’s ethics is the concept of phronesis or practical wisdom, which he identifies as the intellectual virtue that enables us to deliberate well about human affairs. Practical wisdom is crucial because moral virtue without practical wisdom is merely good intention without proper direction, while practical wisdom without moral virtue lacks the proper orientation toward good ends. Practical wisdom involves several interconnected capacities: the ability to perceive morally relevant features of situations, to deliberate well about courses of action, to understand the relationship between particular circumstances and general moral principles, and to act on one’s moral judgments. Unlike theoretical knowledge, which deals with universal and necessary truths, practical wisdom concerns the variable and contextual domain of human action.
Aristotle’s account of practical wisdom has profound implications for moral epistemology. It suggests that moral knowledge cannot be reduced to theoretical knowledge of abstract principles, but requires experiential learning and mature judgment. This view challenges both ancient intellectualist approaches that reduce virtue to knowledge and modern approaches that seek algorithmic solutions to moral problems. The relationship between practical wisdom and moral virtue is reciprocal: we need virtue to see situations clearly and be motivated by appropriate concerns, but we also need practical wisdom to determine what virtue requires in particular circumstances. This unity of the virtues thesis—that genuine virtue requires both good character and good judgment—remains influential in contemporary virtue ethics.
Friendship and the Social Nature of Virtue
Books VIII and IX of the Nicomachean Ethics contain Aristotle’s extended analysis of friendship (philia), which encompasses not only personal friendships but various forms of association and mutual regard. This discussion is not tangential to his ethics but central to his understanding of human flourishing, which he sees as essentially social. Aristotle distinguishes three types of friendship: friendships of utility (based on mutual benefit), friendships of pleasure (based on mutual enjoyment), and friendships of virtue (based on mutual respect for each other’s character). Only the last type constitutes friendship in the fullest sense, as it alone is stable, enduring, and valued for its own sake rather than for external goods.
The analysis of friendship reveals important dimensions of Aristotle’s virtue ethics. First, it shows that human flourishing is not a solitary achievement but requires relationships with others. The virtuous person needs friends not merely for external support but because friendship is itself part of what makes life worth living. Second, friendship provides a context for the exercise and development of virtue—we become virtuous partly through relationships with virtuous others. Aristotle’s discussion of self-love in this context is particularly sophisticated. He argues that proper self-love is not selfish but involves the right kind of concern for one’s own flourishing, which includes the flourishing of others with whom one identifies. The virtuous person loves himself in the right way—by caring for what is best in himself (his rational nature and virtue) rather than for mere pleasure or external goods.
Voluntary Action and Moral Responsibility
Aristotle’s analysis of voluntary action in Book III provides one of the earliest systematic treatments of moral responsibility. He argues that actions are voluntary when they originate in the agent, are done with knowledge of the circumstances, and are not done under compulsion. Actions that fail any of these conditions are involuntary and therefore not praiseworthy or blameworthy. This philosophical analysis raises complex questions about the relationship between character and responsibility. If our actions flow from our character, and our character is formed through habituation, in what sense are we responsible for our actions? Aristotle’s response is that we are responsible for forming our characters through our repeated choices, even if particular actions flow necessarily from established character traits. The discussion of voluntary action also introduces Aristotle’s important distinction between actions done in ignorance and actions done from ignorance. Someone who acts in ignorance lacks knowledge of relevant circumstances, while someone who acts from ignorance (such as a person who is drunk) has brought about their own ignorance. This distinction remains relevant in contemporary discussions of moral and legal responsibility.
Weakness of Will and Moral Psychology
One of the most psychologically acute discussions in the Nicomachean Ethics concerns akrasia or weakness of will, the phenomenon of acting against one’s better judgment. This presents a puzzle: if people really know what is best, how can they fail to do it? Aristotle’s solution involves distinguishing different senses of knowledge and showing how emotion can interfere with practical reasoning.
According to Aristotle, the person with a weak will has knowledge in some sense but fails to apply it properly in action. The knowledge remains at a general level and fails to connect with the particular situation, often because of the interference of passion or appetite. This analysis anticipates modern work in moral psychology on the relationship between cognition and emotion in moral motivation. Aristotle contrasts weakness of will with vice, arguing that the weak-willed person acts against his or her own judgment while the vicious person acts in accordance with a corrupted judgment. This distinction is morally significant: the weak-willed person can be reformed through strengthening their will and improving their habits, while the vicious person requires a more fundamental change in values and perception.
Justice and Political Virtue
Aristotle’s treatment of justice in Book V reveals the essentially political dimension of his ethics. He distinguishes between particular justice (giving people their due in particular transactions and distributions) and universal justice (complete virtue in relation to others). Justice is both a particular virtue and the context within which all virtues are exercised in social relationships. The analysis of distributive justice is particularly influential. Aristotle argues that just distribution involves proportional equality, giving people benefits in proportion to their merit, though he acknowledges that different communities may have different criteria for merit. This principle has influenced theories of distributive justice from ancient times to the present.
Aristotle’s discussion of corrective justice in cases of wrongdoing introduces the principle that justice requires restoring equality by having the wrongdoer compensate the victim. This principle remains central to legal thinking about civil remedies and criminal punishment. The treatment of justice shows how individual virtue connects to a political community. Virtues are not merely private excellences but ways of living well in association with others. This connection between ethics and politics is developed further in Aristotle’s Politics, where he argues that the state exists for the sake of human flourishing.
The Unity of Virtue and the Ideal of Human Excellence
Throughout the Nicomachean Ethics, Aristotle develops a unified vision of human excellence that integrates intellectual and moral virtue. The person of practical wisdom (phronimos) serves as the standard for moral judgment, embodying both good character and good judgment. This ideal figure represents the unity of virtue. The idea that the virtues form an interconnected whole rather than a collection of independent traits.
The unity of virtue thesis is both attractive and problematic. It captures the intuition that genuine virtue involves the integration of various excellences and that moral conflicts often indicate incomplete virtue. However, it may seem to set an impossibly high standard and to ignore the ways that people can be virtuous in some respects while flawed in others. Aristotle’s ideal of human excellence is aristocratic in character, emphasising the importance of education, leisure, and favourable circumstances for the full development of virtue. This raises questions about the accessibility of flourishing and the relationship between individual excellence and social justice. These concerns have led some contemporary virtue ethicists to develop more egalitarian versions of Aristotelian ethics.
Contemplation and the Highest Form of Happiness
In Book X, Aristotle argues that the highest form of human flourishing consists in contemplation (theoria), the activity of philosophical reasoning. This claim seems to conflict with his earlier emphasis on practical virtue and social relationships. The contemplative life is presented as most divine and self-sufficient, requiring fewer external goods than the practically virtuous life.
This tension has generated considerable scholarly debate. Some interpreters argue that Aristotle presents two different conceptions of the best life without adequately reconciling them. Others contend that contemplation represents the peak of human flourishing but does not exclude practical virtue, which remains necessary for complete human development. The emphasis on contemplation reflects Aristotle’s conviction that theoretical reasoning represents the highest human capacity and that philosophy provides the deepest satisfactions. However, his overall ethical theory suggests that most people will find their flourishing primarily in the exercise of practical virtue within social relationships.
Critique and Contemporary Relevance
Aristotle’s virtue ethics has faced various criticisms over the centuries. Medieval philosophers like Thomas Aquinas adapted Aristotelian virtue theory to Christian contexts while addressing some of its apparent limitations. Modern philosophers often criticised virtue ethics as lacking the precision and universality of deontological or consequentialist theories.
However, the late 20th century saw a revival of interest in virtue ethics, initiated by philosophers like Elizabeth Anscombe, Philippa Foot, and Alasdair MacIntyre. This revival was motivated partly by dissatisfaction with rule-based approaches to ethics and recognition that Aristotelian insights about character, practical wisdom, and human flourishing remain compelling. Contemporary virtue ethicists have developed Aristotelian themes in various directions. Some focus on moral psychology and the formation of character. Others explore applications to particular domains like medical ethics, environmental ethics, or feminist ethics. Still others work on theoretical questions about the relationship between virtue and human nature or the structure of moral knowledge. Critics of contemporary virtue ethics argue that it provides insufficient guidance for moral decision-making and that its emphasis on character may neglect questions of justice and rights. Defenders respond that virtue ethics provides a more realistic and psychologically informed approach to moral life than its alternatives.
The Nicomachean Ethics remains one of the most sophisticated and influential works in moral philosophy. Aristotle’s insights about the nature of virtue, the importance of practical wisdom, the social character of human flourishing, and the complexity of moral psychology continue to inform philosophical discussion and practical reflection on how to live well. Perhaps most importantly, Aristotle’s virtue ethics offers a vision of moral life that is both demanding and humane. It sets high standards for human excellence while acknowledging the difficulties and complexities of moral development. It emphasises the importance of character while recognising the need for practical wisdom in navigating particular circumstances. It values individual flourishing while insisting on the essential role of relationships and community.
The enduring appeal of Aristotelian ethics may lie in its recognition that moral philosophy cannot be separated from broader questions about human nature, social life, and the conditions for human flourishing. Rather than offering simple answers or universal rules, the Nicomachean Ethics provides a framework for thinking about these fundamental questions with the sophistication and nuance they require. As we face contemporary moral challenges—from questions about technology and human enhancement to issues of global justice and environmental responsibility—Aristotle’s emphasis on virtue, practical wisdom, and human flourishing offers valuable resources. While we may need to adapt and extend his insights to address new circumstances, the fundamental questions he explored remain as pressing today as they were in ancient Athens. The Nicomachean Ethics thus continues to serve not only as a historical document but as a living source of philosophical insight into the perennial human question of how to live well.
In our current context, where moral discourse often becomes polarised between abstract principles and mere personal preference, Aristotle’s attention to character, community, and the cultivation of practical wisdom offers a valuable alternative. His recognition that moral development requires time, practice, and favourable social conditions remains relevant for thinking about education, public policy, and personal development. The Nicomachean Ethics reminds us that ethics is ultimately about the kind of people we become and the kind of life we lead together—questions that no amount of theoretical sophistication can resolve without attention to the practical wisdom that comes only through experience and reflection on the human condition.
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The Project Gutenberg eBook of The Nicomachean Ethics of Aristotle, by Aristotle
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