IN HIS BOOK What We Owe to Each Other, Thomas Scanlon offers what he calls a 'contractualist' analysis of moral reasons, according to which 'our thinking about right and wrong is structured by ... the aim of finding principles that others, insofar as they too have this aim, could not reasonably reject' (p. 191). (1) Specifically, he argues for the correlative claims that 'an act is wrong if its performance under the circumstances would be disallowed by any set of principles for the general regulation of behaviour that no one could reasonably reject as a basis for informed, unforced general agreement' (p. 153) and that 'an act is right if and only if it can be justified to others' (p. 189), where again the relevant kind of justification is by appeal to principles that could not reasonably be rejected. If Scanlon is correct, such a notion of justifiability is able to explain not only 'the normative basis of the morality of right and wrong' and to provide 'the most general characterisation of its content' (p. 189), but is also able to show both why moral considerations generally have priority over considerations of other kinds and why they have the importance they do.
There are, in effect, two parts to Scanlon's contractualist thesis. The first is that the fact that another creature is rational generates particular constraints on how we may act towards it, and the second is that these constraints provide the basis for describing a non-arbitrarily restricted area of the moral domain. This second point is important, since one of the principal virtues of Scanlon's discussion is that he does not attempt to provide any Procrustean regimentation of our ordinary notion of morality, whose 'fragmentation' he is careful to acknowledge. So, he contrasts what he takes to be the common use of 'morality' amongst moral philosophers--'to refer to a particular normative domain including primarily such duties to others as duties not to kill, harm, or deceive, and duties to keep one's promises'--with our broader non-philosophical use, according to which, for instance, one may think of as immoral particular kinds of sexual activity or someone's failure to have a 'special concern for the interests of his friends or his children' or 'to develop his talents', or if he engages 'in the wanton destruction of works of nature', even when this does not deprive other people 'of resources or opportunities for enjoyment' (p. 172).
Whilst he does not believe that his contractualist analysis will explicate this wider conception of morality, he does think that it will work for the narrower philosophical conception. Nor does he think this limitation is problematic: it should lead one to conclude neither that the wider conception is mistaken about the range of reasons that are to be classed as moral nor that his contractualism is itself mistaken because it fails to account for all the claims on us that we ordinarily count as moral. Rather, we should take his contractualism to characterise 'a central part of the territory called morality' even if that 'does not include everything to which that term is properly applied':
It is apparent that the values at stake in the examples listed
above draw on sources of motivation that are distinct from the one
that underlies the requirements of morality in the narrow sense, or
"what we owe to each other." These values are related to this
central moral idea in important ways, but they are not reducible to
it. (p. 173).
Scanlon's flexibility here is important if he is to secure his claims about morality 'in the narrow sense'. On the one hand, it means that one cannot attack his contractualism simply by finding cases where it would be correct to say that one has moral reason to do something but where these are not susceptible to contractualist analysis or explanation. On the other, it diminishes the danger that his contractualism will itself need to be made trivial in order to accommodate the whole range of reasons that we would ordinarily, and correctly, class as moral. …