Nussbaum and Natural Law Ethics:
Capability Theory and the Human Goods

First draft © by Dr. Jan Garrett

This page last revised October 4, 2005

I. Theories of the Human Good

Contemporary theorists in the tradition of Thomas Aquinas like John Finnis and Alfonso Gomez-Lobo assert the existence of a set of self-evident human goods, without which a moral theory cannot be constructed.

For Finnis, these goods include life, knowledge, play, aesthetic experience, friendship, practical reasonableness, and religion.

For Gomez-Lobo, they include life, family, friendship, work and play, experience of beauty, knowledge, and integrity. These human goods are starting points for further ethical reflection and for the construction of a moral theory.

Most of these correspond to the "primary things in accordance with nature" to which the ancient Stoics referred, as stepping stones to what was for the Stoics the true good, namely living consistently in accordance with nature, or living virtuously.

John Rawls' apparently very different political theory of justice includes a thin theory of the good, i.e., a list of primary goods, all-purpose means, which are the sorts of things that the principles of justice must distribute.

II. Nussbaum's Capabilities and the Human Goods

Martha C. Nussbaum's notion of capabilities, whatever their historical inspiration (and they likely go back directly to Aristotle although Thomas' inspiration may not be lacking), is frequently mentioned by her, and by her direct source, the Nobel Prize winning developmental economist Amartya Sen, in the context of debates inspired by the work of John Rawls.

Nussbaum's chief interest is in the notion of capabilities as it relates to questions of political distributive justice today; in that sense, she is aligned with Rawls.

Thomists, while not lacking an interest in these questions, are often interested in the first place in questions of personal, pre-political morality in which questions like "Should I have an abortion?" "May I have a child out of wedlock?" "May I act on my homosexual desires?" "May I have sex before marriage?" and "May I make a false promise?" figure prominently. This is as one might expect given the place Thomistic natural law theory has in the Catholic tradition and the historical importance of such issues in the confessional.

Mark Murphy ("The Natural Law Tradition in Ethics," in the online Stanford Encyclopedia of Philosophy, 2002) writes that the paradigmatic natural law theory holds that the good is prior to the right (item 5 of 13). Is Nussbaum's ethics of capabilities aligned with natural law theory in this respect?

III. Are the Capabilities Valuable In Themselves?

Clearly the capabilities are prima facie valuable. Otherwise she would not be concerned with assuring their distribution according to human rights.

But a theory of justice or of human rights sometimes focuses on the distribution of instrumental goods, e.g., income, resources, access to health care and education, liberties, and positions of power, etc. This seems to be emphasis in the theory of John Rawls. Nussbaum's capabilities are clearly of value instrumentally, but perhaps not only instrumentally. For instance, the basic capability of life seems desirable for its own sake, not merely as a means, as Finnis and Gomez-Lobo affirm. The internal capacity of health, insofar as it depends upon exercise, seems to be desirable for itself as well as for the functionings it makes possible.

Likewise, moral excellence or virtue (which seems to be a special internal capability that develops rather late when it develops at all) is often regarded as desirable in itself by authors with whom Nussbaum is well acquainted (though there is no room here to review the arguments).

IV. Capabilities and Rawlsian Primary Goods

The kinds of things that Rawls puts into his list of primary goods are things that Nussbaum considers external conditions, which enter into combined capabilities but are not part of basic or internal capabilities. Here we have to be careful, because arguably "external conditions" are important in the generation of internal capabilities and even in the securing of basic capabilities: there will be less training without investment in schools, and the provision or lack of provision of prenatal care to pregnant women may make a difference in the basic capabilities their infants will have. Still, there is a shift of emphasis when we move from Rawls' liberalism to Nussbaum's political theory (itself a form of liberalism).

Indeed, Nussbaum holds the view that capabilities are not only valuable in themselves; they are also valuable instrumentally, for the functionings or activities that they make possible. Roughly, a capability is to a corresponding functioning as, in Thomas Aquinas, habits or first acts are to their corresponding operations or second acts or as in Aristotle, dispositions or hexeis are to their corresponding activities.

But this point regarding capabilities applies more to internal and combined capabilities than to basic capabilities.

V. How the Capabilities Are Distinguished and Interconnected

Nussbaum distinguishes three types of capabilities: basic, internal, and combined even when they ultimately relate to the same class of functionings. They do not have a single definition, any more than in Aristotle and in Thomas potency and first act have a single definition where they relate to the same second act.

But although the three types of capabilities are defined differently, the definitions are linked in a certain order: internal capabilities presuppose, and are defined partly in terms of, basic capabilities while combined capabilities presuppose, and are defined partly in terms of, internal capabilities. One can have basic capabilities without the others, but one cannot have internal without basic, or combined without internal.

Of the three notions, the notion of internal capabilities seems to have the central meaning, because possession of these capabilities, together with suitable external conditions, makes a person actually able to function, to do or be something. But because internal capabilities rest on capacities that seem to come with our biological make-up, it is fitting to call these capabilities too, although they must be distinguished from internal capabilities.

The notion of combined capabilities is clearly composite because even in use, external conditions are often visibly distinct from the person who is using them while activating her internal capabilities. But the term "combined capabilities" is justified because capability suggests a residual degree of potentiality. For even if a person possesses internal capabilities and suitable external conditions, there can be no guarantee that the person will actually engage in the most satisfactory functionings within her reach.

(Aside: it is not possible for someone who possesses an internal capability and a corresponding set of external conditions, to realize all the possible functionings within her range, because any functioning takes time and external conditions can be exhausted in the exercise of one set of functionings. The use of a day, $30 (for gas) and a car for the driving of which one has the skill to take one trip may preclude the taking of a trip in the same car to a different location on the same day and the same $30.)

VI. Metaphysical Rank Ordering

Now, Thomas Aquinas makes much of the distinction between inferior and superior levels of reality. Typically, mere potency is inferior to habit (first act), and habit to activity (second act). This manner of speaking aligns with broadly Platonic assumptions that what is superior is most real and what is inferior is less so, involving contingency and existence of a less complete sort. Thus, for Thomas, supreme happiness for human beings consists in the intellectual vision of the divine essence, which Thomas understands as the full actualization of the highest capacity of human beings, when the supreme being is present to the intellect.

For Nussbaum, a life worth living as a human being would consist of a satisfactory set of satisfactory functionings, in all of the ten areas that she outlines in her list of diverse kinds of capabilities. Presumably, as in Thomas when the acts of the vices and incompletely formed virtues are not fully good, so for Nussbaum not all functionings would count as satisfactory. As we shall see, it's not merely a matter of the mutual compatibility of one person's functionings with that of another.

Nussbaum makes no claims regarding the special closeness of human beings or any of their mental faculties to the angels or to God. Like many philosophers today, she wants her arguments to appeal to reasonable persons of many different religious persuasions, including agnostics, humanists, atheists, and the like.

VII. The Principle of a Universal Floor

It is conceivable that one person's functionings could be compatible with another while the principle of equal regard (PER) is violated, e.g., relationships between exploiter and exploited, for example, in which the exploited accepts her exploited position. This is the sort of thing that would be ruled out by an adequately formulated principle of a universal floor (PUF). Nussbaum asserts the principle of a universal floor (PUF) below which, insofar as possible, no human being should be permitted to fall, at least through social or political neglect by viable societies or states or oppression by groups or individuals.

The moral basis for this is a kind of Principle of Equal Regard (PER), which is based upon the Kantian idea of the equal worth and dignity of every human being. Of course, this has to be interpreted in ways that Kant himself might not have interpreted it: it is interpreted as implying that women, gays, so-called nonwhites, and poor people are of equal worth and dignity with men, straights, so-called whites, and wealthy people, such that they should have real equal opportunity in all diverse departments of areas of capability and functionings.

Thus the PER supports the PUF and the PUF is interpreted in terms of access to the capabilities, especially to the combined capabilities, while attention to internal and basic capabilities are justified because they are preconditions for the possession and exercise of combined capabilities.

VIII. The Principle of Justice

The PUF amounts to a principle of justice regarding how states and, more locally, individuals should treat human beings. The principle of justice in turn becomes a rational criterion by which at least one virtue, the virtue of justice, itself may be measured. The person who has this virtue is one whose actions correspond to the more concrete corollaries of the PUF. While other considerations may enter into the definitions of the virtues other than justice, the PUF does play an important role in their definition as well. No disposition related to conduct can be considered morally virtuous if it contradicts the PUF, insofar as that is realizable.

The more concrete and yet universal principles involving qualitatively particular rights that would be based on the PUF and empirical knowledge of what capabilities important to human development may be called human rights entitlements (HRE's).

My guess is that Nussbaum the capability theorist would concur with Nussbaum the scholar of classical Greek and Roman ethics in regarding moral virtue as an internal disposition that promotes satisfactory functionings. Such an internal disposition supervenes on, or is added to, merely functioning in accord with the rules of non-moral capabilities. Once it appears on the scene, of course, it will react back onto an individual's non-moral capabilities, which provide the matter, so to speak, of which the moral virtues provide the form.

IX. The Duty to Promote Virtue

Once we can make sense out of the notion of human virtue, we acquire a moral obligation to promote the development of virtue. We can call the corresponding principle the principle of virtue promotion (PVP).

This duty is in a sense the duty of everyone, especially of adults in general, and of leaders of families, voluntary associations, business enterprises, and government units.

The intellectual virtue widely known as practical wisdom (what Aristotle called phronesis and Thomas called prudentia) presupposes awareness of the value of virtuous conduct and acceptance of this moral obligation to promote virtue.

X. Human Happiness

Nussbaum's capability theory, it seems to me, suggests the following thin theory of the good life. A minimally good life is one in which one makes use of the capabilities he or she has as a result either of luck or of society's commitment to HRE's (flowing from the PUF and ultimately the PER), develops and lives so as to express a devotion to the PUF and HRE's, and integrates those functionings in an increasingly coherent way.

This allows for the possibility that a person may lead a minimally good life even in an unjust social order. But it also requires that the person develop a genuine devotion to justice (here roughly equivalent to virtue). The likelihood that one will be able to integrate her functionings with justice and in an increasingly coherent way goes down as society's commitment to PUF goes down.

This thin theory of the good life roughly approximates Aristotle's and Thomas Aquinas' secondary sort of human happiness, the sort of happiness that consists in a life of activity in accordance with moral virtue and prudence. Nussbaum does not take up the issue of ranking speculative activity in relationship to practical activity, as Thomas does following Aristotle, nor does she follow Thomas to ask whether a higher form of happiness is possible when (or if) the corruptible body is replaced by the incorruptible body after death. On this point Thomas has taken up questions that are live options only for those willing to make certain faith commitments. Nussbaum, operating within a religiously pluralist society where commitment to immortality is not a given, avoids such speculations.