Aristotle’s View of the Good: Happiness as Rational Activity

 (1) Exposition

In Nicomachean Ethics I.7, Aristotle argues that the human good is happiness (eudaimonia), understood not as a feeling but as rational activity in accordance with virtue. His reasoning proceeds through what is commonly called the “function argument.”

Aristotle begins with a general principle:

1. For anything that has a function (ergon), its good consists in performing that function well.

For example, the good of a flute-player lies in playing the flute well, and the good of a sculptor lies in sculpting well. Excellence (aretē) allows a thing to perform its function properly.

Aristotle then asks whether human beings have a distinctive function. He argues that nutrition and growth cannot be the human function, since plants share these capacities. Nor can perception alone define us, since animals also perceive. What distinguishes humans is rational activity, the ability to reason and to order one’s life in accordance with reason.

Thus:

2. The distinctive function of a human being is rational activity of the soul.
3. The good of a human being is to perform this function well.
4. Therefore, the human good is rational activity in accordance with virtue.

Aristotle further argues that happiness is “final” and “self-sufficient.” It is final because it is pursued for its own sake and never as a means to something else. Wealth, honor, and pleasure are sought for the sake of happiness. Happiness is self-sufficient because it makes life choiceworthy and lacking in nothing essential.

Thus, happiness is not a transient emotion but a complete life of virtuous rational activity.

(2) Objection

A serious objection challenges the assumption that human beings have a single distinctive function at all.

While tools and professions clearly have functions (a knife cuts, a builder builds), it is not obvious that whole human beings have a single unified function in the same sense. Humans engage in a wide range of activities, emotional, social, aesthetic, political, and practical. Why assume that one capacity, namely rationality, defines our function?

Moreover, even if humans are rational animals, it does not immediately follow that rational activity is our defining end. One might argue that humans are equally characterized by emotional depth, creativity, or relational bonds. If no single activity uniquely defines us, then Aristotle’s move from “distinctive capacity” to “defining function” may be unjustified.

If this premise fails, then the inference from “human function” to “human good” collapses. Happiness would no longer be identical with rational activity in accordance with virtue.

(3) Reply to the Objection

Aristotle could respond by clarifying that his claim is not that humans only reason, but that reason governs and orders the other aspects of life.

Human beings indeed possess emotions, desires, and social attachments. However, these capacities are not independent of reason. Emotions can be guided by rational deliberation; desires can be moderated by judgment; political life depends on speech and reasoning about justice.

Thus, rationality is not merely one feature among others. It is the organizing principle of human life. Without reason, emotional and social capacities cannot be properly directed.

Furthermore, Aristotle does not deny that happiness requires external goods, friendships, and social life. Rather, he maintains that these goods become genuinely fulfilling only when integrated into a life guided by practical wisdom (phronēsis).

The function argument therefore does not reduce humanity to abstract reasoning. Instead, it identifies rational activity as the distinctive structure that allows all other human capacities to flourish properly.

(4) Judgment

Aristotle’s function argument is not self-evident, but it is philosophically powerful. The objection raises a legitimate concern: it is not immediately obvious that human beings have a single function analogous to tools. However, Aristotle’s broader account of human nature as rational and political provides substantial support for his conclusion.

His argument succeeds if one accepts two key assumptions:

1. That things are understood in terms of their characteristic activities.
2. That rationality is the defining feature of human life.

If these are granted, the conclusion that happiness is rational activity in accordance with virtue follows coherently.

Even for those who question teleological assumptions, Aristotle’s insight remains compelling: a good human life is not merely a life of pleasure or material success, but one shaped by disciplined reasoning and moral excellence.

Thus, while the function argument invites scrutiny, it remains a deeply influential and defensible account of the human good.

Reference:

The Basic Works of Aristotle, ed. Richard McKeon [1941]. New York: Modern Library, 2001