Aristotle's Function Argument

The Function Argument

Aristotle’s Nicomachean Ethics aims to find the supreme good, or “the highest end of human life” (Lec. Slide W02.2), which he calls eudaimonia. In order to achieve eudaimonia Aristotle argues that one must first find one’s function, what he calls ergon. This later became known as the function argument. This paper will explain eudaimonia, Aristotle’s function argument and its importance in achieving eudaimonia. I will then discuss one objection to the function argument referenced in Christine M. Korsgaard’s paper “Aristotle’s Function Argument”. She offers this objection by questioning Aristotle’s claim that the human function can be only one of three things.

Aristotle argues that every human activity aims at a good,

or something that is desirable (Lec. Slide W02.2). For example, the good, or “end”, of going to school is to learn. The end of eating breakfast is to eat. Some ends are more desirable than others. If an act, like taking medicine, is desired for the sake of its result, feeling better, then the result is more desirable. This inference leads Aristotle to say that ends have a hierarchical structure. Eudaimonia, which means “flourishing” and “living well” is the highest end of human life and according to Lecture Slide W02.2, “It is the only thing that has all three of the following characteristics:
1. It is desirable for itself
2. It is not desirable for the sake of some other good
3. All other goods are desirable for its sake”
Eudaimonia then fits a strict guideline that can be hard to follow. The function argument tells us how to achieve eudaimonia for humans specifically. What consists of the good life for a cat or a river goddess would be different as opposed to a flourishing human life.
Aristotle bases his function argument on the claim that everything, whether it be an artifact (i.e.

something made for a specific purpose) or from nature has a specific ergon, or function. For example, the function of a lamp is to provide light, and for a plant to live. So, a good lamp, would be one that provides light well. Something is considered good, then, by how well it performs its function. But who is to say that, like plants, living is not a human function as well? Aristotle addresses this issue. He claims that if humans are different from, say, plants, then they must also have a differing function from plants. If deities are purely rational beings and animals are driven by instinct and emotion, humans share both these things and land in between the two. This makes humans distinct from other beings. Aristotle recognizes these shared traits and names the human soul in two parts: the non-rational, and the rational, which performs a “special function” (N.E. 1.7 1097a35) unique from plants and animals. The rational side of the soul – one that expresses reason which distinguishes humans from animals – is deemed higher than the non-rational. So, the human function is to express reason. More importantly, humans must express reason well, which involves managing the non-rational side. Aristotle states that, “For in the continent and the incontinent person we praise their reason, i.e. the of the soul that has reason, because it exhorts them correctly and towards what is best;

but they evidently also have in them some other that is by nature something besides reason, conflicting and struggling with reason.” (N.E. 1.13 1102a14-19) The “other part” that Aristotle refers to here is the non-rational, psychological side of humans. One function of the rational side is to manage psychological states and emotions. Aristotle calls this exercising Phronesis, or practical wisdom to reason about moral virtues. Another part of the rational is Sophia, or theoretical wisdom, which concerns itself with intellectual stimulation and “reasoning about things that are highest in all of nature” (Lec W03.2). So, the human manages her psychological state and expresses reason well is a good human who will achieve eudaimonia.
One common objection to the function argument was explained by Christine Korsgaard, who states, “Why should the human function be one of these three things—the life of nutrition and growth, the life of perception, and the life of reason? And of these, why should it be the one that is ‘‘peculiar’’ to us?” That is to say, if aliens were to land on Earth and like humans both expressed reason and shared qualities with plants and animals, would humans still be distinctly human? In defining humans as distinct by a single function, humans lose their individuality, their function, and ultimately cannot achieve eudaimonia if another being shares this same quality.