A theory of Justice: Revised Edition

parts: first, we are to comply with and to do our share in just institutions
when they exist and apply to us; and second, we are to assist in the
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establishment of just arrangements when they do not exist, at least when
this can be done with little cost to ourselves. It follows that if the basic
structure of society is just, or as just as it is reasonable to expect in the
circumstances, everyone has a natural duty to do what is required of him.
Each is bound irrespective of his voluntary acts, performative or other-
wise. Now our question is why this principle rather than some other
would be adopted. As in the case of institutions, there is no way, let us
assume, for the parties to examine all the possible principles that might be
proposed. The many possibilities are not clearly defined and among them
there may be no best choice. To avoid these difficulties I suppose, as
before, that the choice is to be made from a short list of traditional and
familiar principles. To expedite matters, I shall mention here only the
utilitarian alternative for purposes of clarification and contrast, and very
much abbreviate the argument.
Now the choice of principles for individuals is greatly simplified by
the fact that the principles for institutions have already been adopted. The
feasible alternatives are straightway narrowed down to those that consti-
tute a coherent conception of duty and obligation when taken together
with the two principles of justice.
1
This restriction is bound to be particu-
larly important in connection with those principles definitive of our insti-
tutional ties. Thus let us suppose that the persons in the original position,
having agreed to the two principles of justice, entertain the choice of the
principle of utility (either variant) as the standard for the acts of individu-
als. Even if there is no contradiction in this supposition, the adoption of
the utilitarian principle would lead to an incoherent conception of right.
The criteria for institutions and individuals do not fit together properly.
This is particularly clear in situations in which a person holds a social
position regulated by the principles of justice. For example, consider the
case of a citizen deciding how to vote between political parties, or the
case of a legislator wondering whether to favor a certain statute. The
assumption is that these individuals are members of a well-ordered soci-
ety that has adopted the two principles of justice for institutions and the
principle of utility for individuals. How are they to act? As a rational
citizen or legislator, a person should, it seems, support that party or favor
that statute which best conforms to the two principles of justice. This
means that he should vote accordingly, urge others to do likewise, and so
on. The existence of institutions involves certain patterns of individual
conduct in accordance with publicly recognized rules. The principles for
1. For clarification on this point I am indebted to Allan Gibbard.
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Duty and Obligation

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institutions have, then, consequences for the acts of persons holding posi-
tions in these arrangements. But these persons must also regard their
actions as governed by the principle of utility. In this case the rational
citizen or legislator should support the party or statute whose victory or
enactment is most likely to maximize the net balance (or average) of
satisfaction. The choice of the utility principle as the standard for indi-
viduals leads to contrary directives. To avoid this conflict it is necessary,
at least when the individual holds an institutional position, to choose a
principle that matches in some suitable way the two principles of justice.
Only in noninstitutional situations is the utilitarian view compatible with
the agreements already made. Although the principle of utility may have
a place in certain duly circumscribed contexts, it is already excluded as a
general account of duty and obligation.
The simplest thing to do, then, is to use the two principles of justice as
a part of the conception of right for individuals. We can define the natural
duty of justice as that to support and to further the arrangements that
satisfy these principles; in this way we arrive at a principle that coheres
with the criteria for institutions. There is still the question whether the