In the Nicomachean Ethics, philosopher Aristotle lays out his argument for what makes a good and happy human life. Aristotle believes the final end for a human is “eudaimonia”, a state of flourishing and living well. Aristotle says we will understand eudaimonia if we first understand the function of a human. He writes that a thing will be ‘good’ insofar as it performs its function well. For example, a knife will be ‘good’ if it is able to perform its function of cutting well.
Though a knife’s function seems obvious, the function of a human requires more thought. Aristotle poses that the human function is whatever is peculiar to humans. Unlike plants and animals, humans have the unique ability to reason and think rationally. In this, Aristotle claims that “the human function is the soul’s activity that expresses reason or requires reason” (Bk 1, 1098a, 10).
Just as the knife’s sharpness directly determines its ‘goodness’, a human’s capacity to reason effectively directly influences its capacity to reach eudaimonia.
Additionally, Aristotle argues that one’s ability to live life through reason will allow them to identify our natural desires as humans and obtain the ‘goods’ that satisfy these natural desires. These differ from acquired desires, which point more to gratifying pleasures and indulgences such as caviar that do not satisfy our true human needs. Aristotle identifies three types of ‘goods’ that humans should seek; goods of the soul, goods of the body, and external goods. Goods of the soul encompass knowledge, skill, love, friendship, and honor among others.
Bodily goods entail health, vitality, vigor and pleasure. External goods comprise of food, drink, shelter, clothing and sleep.
However, Aristotle notes that while one may have the knowledge of these goods, this is not sufficient to live a good life. Rather, we must learn to desire these goods through the development of good moral character. This good moral character emerges through the development of strong habits, or virtue, as “we become just by doing just actions, temperate by doing temperate actions, brave by doing brave actions” (Bk 1, 1103b, 1-2). Aristotle divides virtue into two classes: intellectual and moral. Intellectual virtues are defined by wisdom and understanding, whereas moral virtues are exemplified by the disposition to actively choose the good correctly. Moral virtue is integral to Aristotle’s good life, as the habit of making right choices determines whether or not we live well. Over time, Aristotle asserts that one will develop moral virtues such as moderation, courage, and justice, and these virtues will eventually deliver one to eudaimonia.
However, one caveat in Aristotle’s good life hinges on the presence of good fortune. While both the knowledge of the good life and good habits to choose the good are essential in reaching eudaimonia, these do not guarantee a flourishing life, since living well is not always in our control. As Aristotle puts it, “happiness evidently also needs external goods to be added, as we said, since we cannot, or cannot easily, do fine actions if we lack the resources. For, first of all, in many actions we use friends, wealth and political power just as we use instruments” (Bk 1, 1099a, 32-34). In conclusion, Aristotle believes happiness is not a condition of the soul, but rather a right activity of the human. The good life is simply rational activity of the soul guided by moral and intellectual virtues, accompanied by good fortune.
In The Republic, Plato gives his account of the just soul. Plato proposes that the soul is composed of three parts: the rational, the appetitive, and the spirited. The rational part discerns what is real, judges what is true, and makes decisions in accordance with a love for goodness. The appetitive part consists of our desires, pleasures, and physical satisfactions, and Plato notes that irrational nature of the appetitive part, describing it as “the part with which it lusts, hungers, thirsts and gets excited by other appetites the irrational appetitive part” (Republic IV, 439d). Lastly, the spirited or hot-blooded part is the part by which we get angry when we perceive an injustice.
This part loves to compete, overcome challenges, and steel adversity. Plato defends this tripartite theory by alluding to appetitive desires such as thirst and hunger, in that when one’s desires to eat or drink are subdued, even when hungry or thirsty, there must be another element causing this. These three parts also correspond to his three classes of society: the guardians or rulers, the auxiliary or soldiers, and the producers. The rational part is seen in the wisdom of the rulers, the spirited part manifests in the courage of the soldiers, and the appetitive part shows itself in the worker’s desire for material gain. Plato puts forth a conception of the ‘just state’ that revolves around fulfilling one’s proper role and realizing one’s ability while not overstepping it.
In Plato’s just state, each class has a specific set of duties, which if fulfilled, results in a harmonious state where everything operates in unison. Plato centers his conception of justice around the idea that everything in nature exists in a hierarchy, with every individual serving an exact purpose. Plato applies this same idea of hierarchy in nature to the soul, in that the three parts of the soul work in a hierarchy. According to Plato, the rational part is superior to the spirited part, which is superior to the appetitive part. However, each of these parts still have necessary parts to play- the rational part should govern the individual, but the appetitive must be heeded in order to maintain harmony and avoid internal conflict. When reason is in control, the soul has sophia, or the virtue of wisdom. When the spirited part assists the rational part, the soul has courage, or andreia. Finally, when the appetitive part exhibits moderation, the soul is temperate, or sophrosune. If every aspect of the soul serves its purpose well, the soul is well-ordered, resulting in a virtuous individual. The virtuous person acts according to his role in the state, and acts within moderation and reason. In Plato’s eyes, a correctly ordered soul is a condition of eudaimonia, a state of human flourishing.
Aristotle and Plato share similar views on what makes a good life, but also diverge in some ways. In Plato’s eyes, a good life results from living a rigidly virtuous life, committed to temperance and fulfilling one’s role in society. Moreover, Plato emphasizes the importance of introspection in one’s life, stating in the book Apology that “the unexamined life is not worth living”. Common to both Plato and Aristotle, constant reflection and desire for more understanding fosters a more flourishing life. For Plato, one’s continual propensity to seek the truth and question one’s surroundings grows one wiser, and this in turn makes one more likely to live a flourishing life.
For people to be truly virtuous, they must learn four cardinal virtues: wisdom, justice, self-discipline, and courage. These four virtues are extracted from Plato’s view of the soul and its three parts, appetite, spirit, and reason. Everyone has these three parts of the soul, but the virtuous are those who correctly balance these in a hierarchy, producing harmony and a well-ordered soul. Plato continues, saying for a person to be virtuous, all desires must be quelled and replaced by a burning desire for knowledge and goodness. In this way, Plato believes that the rational aspect of the soul must maintain a hierarchy over the appetitive, with the assistance of the spirit. In Plato’s vision of the perfect city, he outlines that for a good life, everyone must subscribe to a common vision of good and create an environment in which everyone is just and strives for true happiness. Opposing Plato in this regard, Aristotle believes that simply living well constitutes a good life.
Aristotle and Plato strongly differ in their conceptions of knowing the good vs. practicing the good. Plato claims that coming to know what is good by mastering the use of reason and maintaining a well-ordered soul is sufficient to achieve a flourishing life. Individuals can obtain the virtue of wisdom by living a life driven by curiosity and always seeking to gain more knowledge. By doing this, one will develop new skills and self-understanding, which will in turn lead to a more fulfilling life. Aristotle voices similar messages, claiming that one function of humans is to seek out new knowledge. He believes that humans flourish by gaining new knowledge, and labels this as the “intellectual virtue” of humans. While he agrees with Plato that learning about things will allow one to increase their self-understanding and lead to a more flourishing life, he disagrees that the sole possessing of knowledge is sufficient to achieve eudaimonia. In contrast, Aristotle divides knowledge into theoretical knowledge, knowing the theoretical nature or principle of things, and practical knowledge, the actual application of these principles.
Through this, Aristotle reasons that there is an intellectual virtue, the virtue of acquiring and seeking out new knowledge, and moral virtue, the virtue of acting this knowledge out in everyday life. Unlike Plato, Aristotle claims that one must act out these virtues in order to reach eudaimonia: “And just as Olympic prizes are not for the finest and strongest, but for contestants, since it is only these who win; so also in life only the fine and good people who act correctly win the prize” (Bk 1, 1099a, 4-6). Aristotle poses that intellectual virtues can be acquired over time, but one cannot fully reach eudaimonia unless they develop the virtue of character by practicing and acting out these virtues over time.
Plato and Aristotle converge on the belief that externalities such as wealth or honor will not bring one to eudaimonia. Plato detests external goods, asserting that a lack self-restraint and indulgence of desires will produce a soul full of vice and disorder, and disrupt the harmony in the soul essential for eudaimonia. He believes that temperance is integral to the success of society and of one’s soul, as excess desire invites corruption and chaos in both aspects. To an extent, Aristotle agrees with these stances, asserting that external goods will not in of itself bring one a good life. However, Aristotle stands that these goods are beneficial in augmenting one’s probability of achieving eudaimonia. In Book I, he asserts that “happiness would seem to need this sort of prosperity added also; that is why some people identify happiness with good fortune, while others identify it with virtue” (Bk 1, 1099b, 5). Aristotle asserts that if we are born into advantageous circumstances, external goods like wealth, political power, or good looks will increase one’s chances of reaching eudaimonia.
Although Aristotle’s account has received criticism, his account of the good life appears more plausible than Plato’s totalitarian and rigid account. Aristotle’s account takes a more realistic approach to eudaimonia, as he states that although one can possess the knowledge and habits necessary to live well, the ability to live well may be out of their control. While blunt, his necessitating of fortune and external goods in one’s capacity to live well is very true, as the issue of social justice and improving the lives of the less fortunate pervades to our world today. Further, he appeals to human psychology in his theory of how one develops virtue over time, citing good habits as the vehicle from knowing what is good to doing what is good. Habits are very teachable to the human, requiring regular repetition until the action becomes automatic or habitual. In this way, Aristotle’s account of the good life is very plausible, and appears rational and well-defended.
On the other hand, Plato’s account of the good life is unrealistic and out of touch with human nature, forcing the individual into a strict and rigid way of living. To begin, Plato believes in realizing one’s potential and prescribing an exact role to fit that potential. Further, Plato defends a clear social hierarchy in society, where individuals fulfill their proper role whilst not overstepping it: “Meddling and exchange between these three classes, then, is the greatest harm that can happen to a city and would rightly be called the worst thing someone could do to it” (Republic IV, 434b). A lack of social mobility puts a tight grip on individual freedom, an ideal that most people today value with high importance. If this were put into practice, most people would rebel at the idea of performing one role for the entirety of their lives, with no prospect of advancing or moving up in society.
Additionally, Plato’s good life requires a strict monitoring of indulgences and desires, as these are destructive and invite chaos in society and one’s soul. Further, in Plato’s vision of ‘the perfect city’ every individual must subscribe to the common good, no matter what they might actually desire. This account of the good life forces the individual into a very particular, specific, and rigid way of living, without much individual freedom or self-expression. The idea that justice consists in fulfilling one’s proper role and doing just that opposes our human nature. For these reasons stated, Aristotle’s account of the good life appears more plausible.
In the Nicomachean Ethics, Aristotle’s function argument has a potential weakness in his defining of the human function. Aristotle’s function argument lies on the foundation that everything, inanimate or animate, has a specific function or purpose for which it was designed. Furthermore, it’s ‘goodness’ is directly correlated to how well it performs it’s function; for example, a blunt knife is not ‘good’. In searching for the function of a human, Aristotle looks for the characteristic in a human that is distinctive and completely unique. He identifies three main functions of humans; a life of nutrition and growth, a life of sensory-perception, and a life of action of the soul. The life of nutrition and growth is not plausible, as seems common to all living things. Next, the life of sensory-perception “is apparently shared, with horse, ox and every animal” (Bk 1, 1098a, 1-2), and therefore does not fit Aristotle’s criteria. The remaining life, the life of rational activity of the soul, is deemed the singular human function.
This idea that the human function must be one of these three lives provokes uncertainty and dubiousness and seems somewhat arbitrary. Furthermore, the condition that the function must be exclusive to humans raises even more reservation, for it would not weaken our function as humans if we shared it with another animal. Additionally, Aristotle’s sole condition that our function must be peculiar to us sparks even more doubt: “one could as well, on these principles, end up with a morality which exhorted man to spend as much time possible in making fire; or developing peculiarly human physical characteristics; or despoiling the environment and upsetting the balance of nature; or killing things for fun”1. Even if we agree that the human function must be one of the three lives that Aristotle identifies, Aristotle does not give a rationale for limiting the human function to one thing. Instead, it could be more conceivable if Aristotle’s eudaimonia involved the excellence of all of our essential functions as humans.
Aristotle can resolve these objections by clarifying the difference between purpose and function. Purpose is what something does, function is how something operates. Humans have a definite purpose in what they do, which is to maintain their ability to function in existence. In revisiting Aristotle’s three types of life in the soul, the presence of rational choice in the soul changes the complexion of perceptive and locomotive part of the soul. In this sense, the presence of these parts of the soul changes the way we perceive something to be alive. For example, while all things alive engage in nutrition, the human performs its nutritive and vegetative behavior much differently than a plant may.
In the same vein, a cheetah engages in perception and locomotion much differently than a human, due to the presence of rational choice in our soul. The presence of rational choice differentiates our life from that of an animal or plant and is the inherent characteristic that makes us human. Aristotle chooses reason as our specific function because it is solely responsible in our leading of a specifically human life. Furthermore, eudaimonia translates to “human flourishing or prosperity”, and is a goodness of life that plants and animals are able to reach. It is specifically a human flourishing, and because of this, it makes sense that Aristotle designates our function as something intrinsically and exclusively human. While the objections raised above threaten the validity and strength of Aristotle’s argument, examining how profoundly reason defines the human life and shapes other parts of the soul resolves these criticisms.
1: Korsgaard, Christine M. Aristotle’s Function Argument. 2008, www.people.fas.harvard.edu/~korsgaar/AristotleFunction.pdf.