A theory of Justice: Revised Edition

An Anatomy of Values
(Cam-
bridge, Harvard University Press, 1970), pp. 158–169, and Thomas Nagel, 
The Possibility of Altruism
(Oxford, The Clarendon Press, 1970), esp. ch. VIII.
371
64. Deliberative Rationality

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calculating. But this interpretation rests upon a misunderstanding. The
first aim of the theory is to provide a criterion for the good of the person.
This criterion is defined chiefly by reference to the rational plan that
would be chosen with full deliberative rationality. The hypothetical na-
ture of the definition must be kept in mind. A happy life is not one taken
up with deciding whether to do this or that. From the definition alone very
little can be said about the content of a rational plan, or the particular
activities that comprise it. It is not inconceivable that an individual, or
even a whole society, should achieve happiness moved entirely by sponta-
neous inclination. With great luck and good fortune some men might by
nature just happen to hit upon the way of living that they would adopt
with deliberative rationality. For the most part, though, we are not so
blessed, and without taking thought and seeing ourselves as one person
with a life over time, we shall almost certainly regret our course of action.
Even when a person does succeed in relying on his natural impulses
without misadventure, we still require a conception of his good in order
to assess whether he has really been fortunate or not. He may think so,
but he may be deluded; and to settle this matter, we have to examine the
hypothetical choices that it would have been rational for him to make,
granting due allowance for whatever benefits he may have obtained from
not worrying about these things. As I noted before, the value of the
activity of deciding is itself subject to rational appraisal. The efforts we
should expend making decisions will depend like so much else on cir-
cumstances. Goodness as rationality leaves this question to the person
and the contingencies of his situation.
65. THE ARISTOTELIAN PRINCIPLE
65. Aristotelian Principle
The definition of the good is purely formal. It simply states that a per-
son’s good is determined by the rational plan of life that he would choose
with deliberative rationality from the maximal class of plans. Although
the notion of deliberative rationality and the principles of rational choice
rely upon concepts of considerable complexity, we still cannot derive
from the definition of rational plans alone what sorts of ends these plans
are likely to encourage. In order to draw conclusions about these ends, it
is necessary to take note of certain general facts.
First of all, there are the broad features of human desires and needs,
their relative urgency and cycles of recurrence, and their phases of devel-
opment as affected by physiological and other circumstances. Second,
372
Goodness as Rationality

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plans must fit the requirements of human capacities and abilities, their
trends of maturation and growth, and how they are best trained and
educated for this or that purpose. Moreover, I shall postulate a basic
principle of motivation which I shall refer to as the Aristotelian Principle.
Finally, the general facts of social interdependency must be reckoned
with. The basic structure of society is bound to encourage and support
certain kinds of plans more than others by rewarding its members for
contributing to the common good in ways consistent with justice. Taking
account of these contingencies narrows down the alternative plans so that
the problem of decision becomes, in some cases anyway, reasonably
definite. To be sure, as we shall see, a certain arbitrariness still remains,
but the priority of right limits it in such a way that it is no longer a
problem from the standpoint of justice (§68).
The general facts about human needs and abilities are perhaps clear
enough and I shall assume that common sense knowledge suffices for our
purposes here. Before taking up the Aristotelian Principle, however, I
should comment briefly on the human goods (as I shall call them) and the
constraints of justice. Given the definition of a rational plan, we may
think of these goods as those activities and ends that have the features
whatever they are that suit them for an important if not a central place in
our life.
19
Since in the full theory rational plans must be consistent with
the principles of justice, the human goods are similarly constrained. Thus
the familiar values of personal affection and friendship, meaningful work
and social cooperation, the pursuit of knowledge and the fashioning and
contemplation of beautiful objects, are not only prominent in our rational
plans but they can for the most part be advanced in a manner which
justice permits. Admittedly to attain and to preserve these values, we are
often tempted to act unjustly; but achieving these ends involves no inher-
ent injustice. In contrast with the desire to cheat and to degrade others,
doing something unjust is not included in the description of the human
goods (§66).
The social interdependency of these values is shown in the fact that not
only are they good for those who enjoy them but they are likely to
enhance the good of others. In achieving these ends we generally contrib-
ute to the rational plans of our associates. In this sense, they are comple-
mentary goods, and this accounts for their being singled out for special
commendation. For to commend something is to praise it, to recount the
19. For the explanation of these goods I have drawn from C. A. Campbell, “Moral and Non-Moral
Values,” 
Mind,
vol. 44 (1935); see pp. 279–291.
373
65. Aristotelian Principle

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properties that make it good (rational to want) with emphasis and expres-
sions of approval. These facts of interdependency are further reasons for
including the recognized values in long-term plans. For assuming that we
desire the respect and good will of other persons, or at least to avoid their
hostility and contempt, those plans of life will tend to be preferable which
further their aims as well as our own.
Turning now to our present topic, it will be recalled that the Aristote-
lian Principle runs as follows: other things equal, human beings enjoy the
exercise of their realized capacities (their innate or trained abilities), and
this enjoyment increases the more the capacity is realized, or the greater
its complexity.
20
The intuitive idea here is that human beings take more
pleasure in doing something as they become more proficient at it, and
of two activities they do equally well, they prefer the one calling on a
larger repertoire of more intricate and subtle discriminations. For exam-
ple, chess is a more complicated and subtle game than checkers, and
algebra is more intricate than elementary arithmetic. Thus the principle
says that someone who can do both generally prefers playing chess to
playing checkers, and that he would rather study algebra than arithmetic.
We need not explain here why the Aristotelian Principle is true. Presum-
ably complex activities are more enjoyable because they satisfy the desire
for variety and novelty of experience, and leave room for feats of ingenu-
ity and invention. They also evoke the pleasures of anticipation and sur-
prise, and often the overall form of the activity, its structural develop-
20. The name “Aristotelian Principle” seems to me appropriate in view of what Aristotle says about
the relations between happiness, activity, and enjoyment in the