A theory of Justice: Revised Edition

Nicomachean Ethics,
bk. VII, chs.
11–14, and bk. X, chs. 1–5. Yet since he does not state such a principle explicitly, and some of it is at
best only implied, I have not called it “Aristotle’s Principle.” Nevertheless, Aristotle certainly affirms
two points that the principle conveys: (1) that enjoyment and pleasure are not always by any means
the result of returning to a healthy or normal state, or of making up deficiencies; rather many kinds of
pleasure and enjoyment arise when we exercise our faculties; and (2) that the exercise of our natural
powers is a leading human good. Further, (3) the idea that the more enjoyable activities and the more
desirable and enduring pleasures spring from the exercise of greater abilities involving more complex
discriminations is not only compatible with Aristotle’s conception of the natural order, but something
like it usually fits the judgments of value he makes, even when it does not express his reasons. For a
discussion of Aristotle’s account of enjoyment and pleasure, see W. F. R. Hardie, 
Aristotle’s Ethical
Theory
(Oxford, The Clarendon Press, 1968), ch. XIV. The interpretation of Aristotle’s doctrine given
by G. C. Field, 
Moral Theory
(London, Methuen, 1932), pp. 76–78, strongly suggests what I have
called the Aristotelian Principle. Mill comes very close to stating it in 
Utilitarianism.
ch. II, pars. 4–8.
Important here is the concept of effectance motivation introduced by R. W. White, “Ego and Reality
in Psychoanalytic Theory,” 
Psychological Issues,
vol. III, 1963), ch. III, upon which I have relied.
See also pp. 173–175, 180f. I am indebted to J. M. Cooper for discussion on the interpretation of this
principle and the propriety of its name.
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ment, is fascinating and beautiful. Moreover, simpler activities exclude
the possibility of individual style and personal expression which complex
activities permit or even require, for how could everyone do them in the
same way? That we should follow our natural bent and the lessons of our
past experience seems inevitable if we are to find our way at all. Each of
these features is well illustrated by chess, even to the point where grand
masters have their characteristic style of play. Whether these considera-
tions are explanations of the Aristotelian Principle or elaboration of its
meaning, I shall leave aside. I believe that nothing essential for the theory
of the good depends upon this question.
It is evident that the Aristotelian Principle contains a variant of the
principle of inclusiveness. Or at least the clearest cases of greater com-
plexity are those in which one of the activities to be compared includes all
the skills and discriminations of the other activity and some further ones
in addition. Once again, we can establish but a partial order, since each of
several activities may require abilities not used in the others. Such an
ordering is the best that we can have until we possess some relatively
precise theory and measure of complexity that enables us to analyze and
compare seemingly disparate activities. I shall not, however, discuss this
problem here, but assume instead that our intuitive notion of complexity
will suffice for our purposes.
The Aristotelian Principle is a principle of motivation. It accounts for
many of our major desires, and explains why we prefer to do some things
and not others by constantly exerting an influence over the flow of our
activity. Moreover, it expresses a psychological law governing changes in
the pattern of our desires. Thus the principle implies that as a person’s
capacities increase over time (brought about by physiological and bio-
logical maturation, for example, the development of the nervous system
in a young child), and as he trains these capacities and learns how to
exercise them, he will in due course come to prefer the more complex
activities that he can now engage in which call upon his newly realized
abilities. The simpler things he enjoyed before are no longer sufficiently
interesting or attractive. If we ask why we are willing to undergo the
stresses of practice and learning, the reason may be (if we leave out of
account external rewards and penalties) that having had some success at
learning things in the past, and experiencing the present enjoyments of
the activity, we are led to expect even greater satisfaction once we acquire
a greater repertoire of skills. There is also a companion effect to the
Aristotelian Principle. As we witness the exercise of well-trained abilities
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by others, these displays are enjoyed by us and arouse a desire that we
should be able to do the same things ourselves. We want to be like those
persons who can exercise the abilities that we find latent in our nature.
Thus it would appear that how much we learn and how far we edu-
cate our innate capacities depends upon how great these capacities are
and how difficult is the effort of realizing them. There is a race, so to
speak, between the increasing satisfaction of exercising greater realized
ability and the increasing strains of learning as the activity becomes
more strenuous and difficult. Assuming that natural talents have an upper
bound, whereas the hardships of training can be made more severe with-
out limit, there must be some level of achieved ability beyond which the
gains from a further increase in this level are just offset by the burdens of
the further practice and study necessary to bring it about and to maintain
it. Equilibrium is reached when these two forces balance one another, and
at this point the effort to achieve greater realized capacity ceases. It
follows that if the pleasures of the activity increase too slowly with rising
ability (an index let us suppose of a lower level of innate ability), then the
correspondingly greater efforts of learning will lead us to give up sooner.
In this case we will never engage in certain more complex activities nor
acquire the desires evoked by taking part in them.
Now accepting the Aristotelian Principle as a natural fact, it will gener-
ally be rational, in view of the other assumptions, to realize and train
mature capacities. Maximal or satisfactory plans are almost certainly
plans that provide for doing this in significant measure. Not only is there
a tendency in this direction postulated by the Aristotelian Principle, but
the plain facts of social interdependency and the nature of our interests
more narrowly construed incline us in the same way. A rational plan—
constrained as always by the principles of right—allows a person to flour-
ish, so far as circumstances permit, and to exercise his realized abilities as
much as he can. Moreover, his fellow associates are likely to support
these activities as promoting the common interest and also to take pleas-
ure in them as displays of human excellence. To the degree, then, that the
esteem and admiration of others is desired, the activities favored by the
Aristotelian Principle are good for other persons as well.
There are several points to keep in mind in order to prevent misunder-
standings of this principle. For one thing, it formulates a tendency and not
an invariable pattern of choice, and like all tendencies it may be overrid-
den. Countervailing inclinations can inhibit the development of realized
capacity and the preference for more complex activities. Various hazards
and risks, both psychological and social, are involved in training and
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prospective accomplishment, and apprehensions about these may out-
weigh the original propensity. We must interpret the principle so as to
allow for these facts. Yet if it is a useful theoretical notion, the tendency
postulated should be relatively strong and not easily counterbalanced. I
believe that this is indeed the case, and that in the design of social
institutions a large place has to be made for it, otherwise human beings
will find their culture and form of life dull and empty. Their vitality and
zest will fail as their life becomes a tiresome routine. And this seems
borne out by the fact that the forms of life which absorb men’s energies,
whether they be religious devotions or purely practical matters or even
games and pastimes, tend to develop their intricacies and subtleties al-
most without end. As social practices and cooperative activities are built
up through the imagination of many individuals, they increasingly call
forth a more complex array of abilities and new ways of doing things.
That this process is carried along by the enjoyment of natural and free
activity seems to be verified by the spontaneous play of children and
animals which shows all the same features.
A further consideration is that the principle does not assert that any