The foremost defender of rational choice contractarianism is David Gauthier. In his book Morals by Agreement, Gauthier puts forward a contractarian view of morality. Describing his project in that book, he says that
We shall develop a theory of morals as part of the theory of rational choice. We shall argue that the rational principles for making choices, or decisions among possible actions, include some that constrain the actor pursuing his own interest in an impartial way. These we identify as moral principles.
"Morality", Gauthier says, "can be generated as a rational constraint from the non-moral premisses of rational choice". He claims to have given morality "a sure grounding in a weak and widely accepted conception of practical rationality". All this sure sounds as if what Gauthier wants to do is to justify morality. However, in an independent essay written a few years after Morals by Agreement, Gauthier seems to suggest something quite different:
Deliberative justification [of a set of constraints on action] does not refute morality. Indeed, it does not offer morality the courtesy of a refutation. It ignores morality and seemingly replaces it.
Corresponding to these two strands in Gauthier's thinking, I believe that rational choice contractarianism is actually open to two radically different interpretations:
- Contractarianism is a way to justify morality and thereby to overcome moral scepticism. Thus understood contractarianism is a position within normative ethics alongside, for example, utilitarian and Kantian ethics. I will call this first interpretation moral contractarianism.
- Contractarianism is not another moral theory but rather an alternative to moral theorising as such. Thus understood it is an approach to rational constraints on interpersonal behaviour that is fully compatible with moral scepticism (and perhaps even partly motivated by commitment to moral scepticism). This I call non-moral contractarianism.
On 1, the social contract is morality. On 2, the social contract is instead an alternative to morality. I believe that Gauthier himself prefers 1 over 2, but I favour the second interpretation. One benefit of the non-moral interpretation is that it insulates contractarianism from "the relevance objection". Here is Holly Smith posing this objection:
We may characterize what Gauthier has done as arguing that individual rationality, or self-interest, requires a person to dispose herself to perform certain cooperative acts, and then actually to perform those acts when the time comes. Suppose we assume that the acts in question are precisely the same ones that morality requires. Still, the success of this argument would not show that morality has been provided with a justification. It would show that we have self-interested reasons to do what morality, if it were true (or correct), would demand - but it would not show that morality is true.
The non-moral contractarian can of course agree with all this and is thus not threatened by this objection. At this point one could perhaps think that the issue boils down to a merely verbal dispute about what deserves to be called by the label "morality". But I don't think this is so. Distinguishing between two very different types of justification will, I believe, bring out the seriousness of the objection. Traditional normative ethical theories aim at epistemic justification, arguments are provided for the truth (or correctness) of some moral claim or principle. This is the type of justification required for moral knowledge. The contractarian, by contrast, aims at deliberative or instrumental justification; he aims to show that adopting certain constraints on our behaviour towards others is beneficial for each person. Justifying a set of rules in the latter sense of justification falls way short of justifying them in the former sense of justification. Pointing out that deliberative or instrumental justification of a set of constraints on action is fully compatible with moral nihilism - the view that there are no moral facts, that nothing is morally right or wrong, obligatory or forbidden, etc. - should suffice to make this clear. The moral contractarian, who claims to be able to provide morality with a justification, needs to respond to this challenge, presumably by trying to convince the critic that despite appearances deliberative justification is the relevant sort of justification for morality. The non-moral contractarian remains unperturbed by all this and can readily accept that the epistemic type of justification is the relevant one for morality and that contractarianism fails to provide this - but, they hold, so much worse for morality!
Opting for the non-moral interpretation of contractarianism would bring Gauthier closer to the views of John L. Mackie in Ethics: Inventing Right and Wrong, Richard Garner in Beyond Morality, and Richard Joyce in The Myth of Morality. What these authors lack, however, and what Gauthier brings to the table, is a developed technical apparatus gathered from rational choice theory, game theory, and economic theory.
Personally, I think that it is when one has come to accept moral scepticism and nihilism that rational choice contractarianism becomes most attractive. Once one has come to believe that there are no moral facts, no objective values, no real moral obligations woven into the "fabric of the universe", and no moral knowledge, then rational agreement for mutual benefit readily suggests itself as an alternative approach to judging social rules. The non-moral social contract can still, I believe, function as a (pre-legal, pre-political) benchmark for evaluating social and political institutions and practices (it just won't be a matter of moral evaluation). It is this that I prefer to call "morality version 2.0".