Human Function: Aristotle’s Basis for Ethical Value
Adrian Pritchett
The University of Georgia
Athens, Georgia
March 26, 2004
Human Function: Aristotle’s Basis for Ethical Value
I. Aristotle’s Virtue Ethics Depend on the Human Function
Aristotle presents a system of virtue ethics in Nicomachean Ethics. This work presents a prescriptive theory with the aim of showing how humans may reach a proper state of happiness in which the natural human end is fulfilled. This end is regarded as an end in itself to which subordinate ends are related. This master end itself is understood as a type of activity rather than a state that can be achieved with a limited series of actions, and this activity is described as a general practice of acting well in accord with reason. The Ethics launches an inquiry into what makes human happiness, or eudaimonia, possible, and Aristotle believes this is the highest good for mankind. Aristotle expresses this good as being the highest end that action reaches for, which is something self-sufficient, and he suggests that to understand action we should understand function. He presents his concept of the human function and says that humans must function well in order to reach the highest good. Functioning well is what is understood as virtue, and so his system of virtue ethics is overall concerned with humans functioning well.
Functioning well is seen as aiming at a mean between excess and deficiency. The virtue of a thing is understood in terms of its function. A function fulfills a need, and a need is met by being provided the right amount of something but not too much or too little. This is why a craftsman designs goods without excess or deficiency — so that they will function well — and likewise human virtue must be understood as aiming between excess and deficiency. So the Nicomachean Ethics develops a system where all value for human life is determined by what follows from the determination of how the human function is to be performed well. The value of actions that may be performed or goods that may be acquired are measured by how well they will help the deciding agent to act virtuously, and the extremes and deficiencies of actions and goods are determined by whether they will maximize or minimize that value.
To make this concept of value more concrete, we should consider what embodies the virtue of functioning well in accord with reason. For Aristotle, this means that virtue can be exercised either in a political life or a life of contemplation. The political life allows an exercise of reason about human affairs, so it exercises the human function and allows fulfillment of the human end. According to the Politics, the political life occurs in a sphere organized hierarchically above the village and household and is made possible when humans meet their needs at those lower levels. (However, the political sphere also makes decisions about how to meet needs more efficiently.) The political sphere is characterized by self-sufficiency. The life of contemplation, though, as introduced in Book I and discussed in Book X of the Ethics, is made possible when politics takes care of human affairs, and it is the superior of the two forms of virtuous lives. Contemplation is more godlike because it is the purest exercise of reason free of the earthly conflicts that trouble the political sphere; it is the most continuous and most self-sufficient. This confirms Aristotle’s conception of the gods as permanent and unchanging.
II. The Human Function Argument
Now we turn to the basis of Aristotle’s whole ethical theory, the human function argument, which is found in Book I, Chapter 7 of the Ethics (approximately between lines 1097b24 and 1098a9). He argues that the human function is activity of the soul that expresses or requires reason. The argument is organized as follows:
It should be noted that in defining Aristotle’s concept of the human function this argument is not left alone because an understanding of his other arguments along with possible unstated assumptions allow a fuller reconstruction of this argument. However, the above reflects the way it is explicitly presented in the Ethics.
To present the first premise, that humans must have a function or else they would be idle, Aristotle directly asks if humans might have no overall function, but he seems to think this would be absurd in light of the way that people in occupations in society clearly carry out functions. Aristotle negates that second disjunct with the next premise that asserts that humans indeed have a function because the organization of the human body indicates such. This premise is more convincing when it is considered that the body parts that Aristotle names — eye, hand, and foot — clearly have functions and that they themselves are composed of smaller parts with their own subordinate functions. Since each level of organization has a function comprising a hierarchy of functions, Aristotle believes that the highest level of organization, the complete human body, must have an overall function. This makes it clear why it might be absurd for humans to be idle by nature.
The third premise, that the human function is unique to only humans themselves, fits into the argument well at this point because it explains Aristotle’s method of finding the human function, though this assumption is more transparent after the next premise. He is going to eliminate possibilities based on the idea that no other organism shares its function with humans. This remains an undefended guiding assumption. The fourth premise, that the human function is not growth and nutrition, is an exclusion that can now be made only upon acceptance of the third. Since the human function must be unique, and since plants seem to only function in terms of nutrition, the human function must be different. Aristotle is comfortable with this deduction and moves on. The fifth premise rules out the possibility of function grounded upon sense perception, and this is likewise an elimination made because it is not unique to humans. Aristotle says that animals function in the mode of sense perception and still clings to the assumption of human uniqueness.
After the process of elimination, the assertion that the part of human soul with reason is unique to humans becomes the sixth premise. In light of the nature of a function, which is to perform an activity, Aristotle qualifies his finding by introducing a seventh premise that mere capacity for reason cannot constitute a function. He says that the rational part of the human soul has a part with capacity for and obedience to reason, and another part that exercises reason. So he now concludes that the human function is the activity of the part of the soul that expresses or requires reason.
To be sure, this argument is crafted logically. However, a lot of the assumptions are simply unsupported in this passage from the Nicomachean Ethics and so they have many ways in which they could be shown to be false. Aristotle’s assertion that humans even have a function is optimistic or possibly reached by faulty assumptions. In the first premise, he does not show why humans must by nature have a function, but his tone suggests that the alternative is not even worth considering. His second premise rests on an analogy based on a hierarchy of known body parts and function, though it could be fallacious to conclude that there is a function for the whole human body.
C. D. C. Reeve finds a sort of defense for the absurdity of not having a function shortly before this text at line 1095b31. There Aristotle suggests that if humans’ highest end is not an active function then they could be eudaimôn while only sleeping or suffering misfortune,1 but I believe this indirect defense leaves open the possibility that the human function could simply be passive survival. It is desirable to find an active human function to find a plausible form of happiness, but the success of Aristotle’s ethics will remain contingent on the truth of this premise.
The second premise actually is fallacious if Aristotle is confounding two types of functions: the functions of body parts serve a larger part, the whole body that they belong to, yet Aristotle does not say what larger whole in the hierarchy of functions that the human function serves. If the human function instead serves the human itself, then the human function is an end in itself, but the lower functions appealed to in the analogy are ends for the sake of higher ends, so the analogy would fail. We already know that Aristotle is actually looking for an end in itself because of his discussions of the two types of ends earlier in chapter one and the self-sufficiency of happiness in this seventh chapter, so he is mixing these two types of functions here.
The third premise that the human function must be unique is much more controversial, and we will consider its problems with the fourth and fifth premises since they conduct a process of elimination that depend on it. Aristotle does not explain here why the human function must be unique. One possibility is that if an ecological view were taken it could be argued that each type of organism has a unique niche to fill in order to benefit a whole community of flora and fauna, but Aristotle says nothing like that in this work.
A stronger possibility is that Aristotle is working in anthropocentric terms and assuming the uniqueness of man. Earlier around line 1095b2 he writes that he is beginning from what is commonly known to launch the inquiry of the Ethics. We should note that it has been commonly believed throughout history that man is especially unique among all life forms. Usually, however, it is believed that humans are unique because of our rational capacity, so it appears that if Aristotle is relying on common beliefs here then he has begged the question when he deduces that reason is the unique human feature. Of course, common beliefs do hold that proper happiness would seem to be more than mere survival, so it may be appropriate to maintain these beliefs if one has interest in following Aristotle’s inquiry.
Survival, though, should be considered as a possible human function because Aristotle hardly argues against it in the passage in question. He holds that the human function could not be something shared with plants or animals, but when we compare humans with plants and animals it seems that the unique human feature, reason, is necessary to do what plants and animals do without it, which is to merely survive. In fact, this is a classical understanding found in Plato’s Protagoras (320c). Humans have deficient senses and physical capabilities and so we must use our intelligence to make tools and plan ahead in order to overcome these deficiencies.
The crux of this point about survival is that it is possible but not logically necessary for things with different feature sets to have different functions. An example of different things having different features would be the comparison of a steak knife to a pruning knife: each has a different design, and they are designed to cut different things. Conversely, the comparison of a regular screwdriver to an electric screwdriver yields very different features but the same function: each can act on the same type of screw, but the electric one usually functions better. Likewise, Aristotle did not rule out the possibility of all life-forms having the same survival function. Plants have the function of growth and nutrition, but humans can possibly perform this function better — or at least differently — due to their sense perception, mobility, and cunning, so it is not clear by looking at biological capabilities that humans have a special function.
Regarding the sense perception of animals, we can find a closely situated argument (1095b16) from Aristotle against finding the human function in this realm. There Aristotle was searching for a way to define happiness as the highest good and determining what sort of life it involves. He rejected the life of gratification in the manner of animals as slavish and vulgar, so if we agree that animal function is in the mode of sense perception and that living like an animal is unacceptable, then it seems reasonable to rule out sense perception as a human function; but even that argument may only rest on the assumption of uniqueness.
Richard Kraut addresses a criticism of Aristotle’s findings by his process of elimination in determining what is unique to humans.2 This criticism points out that reason may not be unique after all. Specifically, it says that Aristotle’s highest end for man is contemplation, based on the human function of exercising reason; but since Aristotle later notes that the gods contemplate, the end of contemplation and thus the rational faculty are not unique to humans. So this is another way the argument could fail.
Kraut’s defense of Aristotle here is to say that we have misinterpreted the text to understand the exclusion of shared features to be absolute; rather, it should not be common among living things. Further, the class of living things including the gods is a broader class than the class of plants, animals, and humans, so Aristotle is addressing this earthly class. I would like to add that this distinction of classes may be considered quite important since the gods were regarded as permanent, unchanging, and not subject to the vagaries of earthly life, so the gods may easily be removed from the consideration of living things in this argument. I anticipate that such a distinction can be confirmed elsewhere in Aristotle’s works.
Kraut also disposes of a criticism made within this earthly class concerning how to identify the right human peculiarity as the human function: If something peculiar to only humans must be elevated to the status of the human function, then it could be said that using fire, making bridles, or some other activity is mankind’s highest end. But these kinds of activities serve subordinate ends, so Aristotle is clearly looking for a different kind of human peculiarity, one worthy of being an end in itself. So at least this criticism indicates the difficulty of using Aristotle’s process of elimination on biological features or life activities.
Reeve also gets rid of this problem with a pithy explanation: “The specialness of the human function derives from the specialness of the human essence to which it is identical, but neither the function nor the essence is determined by what is special.” This means that human activities derive from the human essence, but none of the activities themselves are the essence. Aristotle seeks to find the human essence as the function and not merely point to one of several peculiar human properties as the function.3
At this point we have seen different ways that the human function argument could fail, but we should consider the possibility that it could fail in a way that causes it to miss its intent yet still succeed in a way that leaves the theory of the Ethics intact. To do this we must return to survival and Aristotle’s position regarding it. Aristotle is looking for a highest good for humans that is beyond mere survival. Human activity in the realms of growth–nutrition and sense perception seems adequate for a person to survive as an animal, and the Politics makes it clear that the political state is not for survival but for fulfilling the special human end beyond it, since the household is sufficient for survival. The state and its role in virtue dominates the Ethics, so Aristotle never seems concerned with survival here. Without reason and without the state, man is merely an animal not aiming at its teleological function.
In contrast, the classical conception of man’s need of reason for survival mentioned above holds that reason is necessary for survival. Again, the human body does is not strong and keen enough to exist without rationally guided work to obtain food, clothing, and shelter. So Aristotle is right to identify reason as a unique human characteristic, and he is right to focus on the use of reason since only its proper development allows survival. However, in his human function argument Aristotle has not shown that reason has a special function unrelated to growth–nutrition and sense perception, so he may be wrong to elevate it to a special status and exclude those lower life processes. If all three are simply working together, then the human function is to survive, which is not unique after all; but the uniqueness lies in the method of survival, which is like the example above where the electric screwdriver was unique but lacked a unique function. The implication would be that since Aristotle’s theory in the Ethics is based on reason, its prescription of virtues might still stand while the human function could be expressed as surviving well, though that is clearly not what he intended. I will leave this as a suggestion and not develop it further.
III. Conclusion
We have seen that Aristotle’s human function argument uses undefended assumptions and ignores obvious objections as it builds. The argument itself is very brief, yet it is the fundament in his theory of virtue ethics. Regardless of these problems, the attention it receives is overshadowed by the attention given to the ethical prescriptions that follows from it. My concern is that philosophers discuss the virtues without due regard for the role of human function. Of course, the defenders of this function argument are able to explain that portion of Aristotle’s theory and move on, but that is precisely where the problem lies.
Just a few of the defenses and explications of this argument touched on here require the citation of seven different works by Aristotle. So the problem is that to explain the human function argument we must construct an argument that Aristotle never actually made. It appears that the premises of function argument are argued for elsewhere, but such interpretation itself requires defense, especially in light of charges of inconsistency made against Aristotle. Since scholars argue over precise meanings of words as they appear in different texts and over which is the best argument made by Aristotle regarding a topic, then it is not totally clear, for example, that a biological argument in De Anima was intended to be directly connected to the human function argument in the Nicomachean Ethics, even though it fits conveniently and parallels the discussion of life features.
It is obvious that problems with the human function argument have implications for the virtues that Aristotle prescribes. Stable conclusions about the value of actions cannot be made if it is uncertain whether Aristotle accurately characterizes the human function. Not only that, but if the human function is sufficiently different, then the political and contemplative spheres of life would be meaningless ways to organize the concepts of living virtuously. Worse still, if there is no human function, then the concept of virtue as acting well in any regard would be of no use whatsoever.
The challenge is to make good sense of Aristotle’s human function argument. It is quite defeasible alone in its passage and merely plausible in the context of the whole Nicomachean Ethics. Supplementing the argument with definitions and sub-arguments from Aristotle’s other works raises a complex set of questions of interpretation concerning the entire corpus, again leaving the function argument merely plausible. I conclude that to be convinced of this argument we need a clear, linear argument of interpretation derived from only a segment of Aristotle’s work that is small enough to remain clear and consistent. Accepting Aristotle’s virtues depends on accepting his human function argument first, so one cannot be convinced of his virtues while leaving open questions about human function.
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1 C. D. C. Reeve, Practices of Reason: Aristotle’s Nicomachean Ethics (New York: Oxford University Press, 1992) 124.
2 Richard Kraut, Aristotle on the Human Good (Princeton: Princeton University Press, 1989) 313-16.
3 Reeve 125-26.