According to the theory of contractarianism, the moral and political principles we should follow are those we would accept in a hypothetical contract. Contractarians often present a scenario in which no moral or political principles have been accepted yet, and we need to find some of those principles. The contractarian argues that the principles we would accept in the scenario they present are those we should accept in the real world.

For instance, in the 17th century, Thomas Hobbes claimed that without any political rule, we would all live in a state of nature in which our lives would be continuously threatened. In this state of nature we would choose, Hobbes argued, to adopt a political system that granted our security.1 In this model, rational agents would choose their political system by means of a hypothetical contract. They would do so because otherwise they would harm each other. So it is a matter of power. Rational agents have the power to harm others, and they can choose to mutually give up that power for the sake of their own security.

Contemporary contractarians have a different approach. Like Hobbes, they claim that the idea of the social contract is a device to see which norms can be legitimately chosen. They differ in what would make these norms legitimate. To contemporary contractarians, it is if we would accept them in a situation in which we  reflected on the matter under conditions of fairness, requiring impartiality. For instance, John Rawls invites us to imagine a situation in which we have to choose the norms of the society we will live in while being completely ignorant of all facts regarding what our place will be in that society, as well as our physical constitution, our ethnicity, and so on. It is supposed that in such a situation the norms we would accept would be legitimate, as we would maintain impartiality.2 Thomas Scanlon has argued that we should accept acting according only to those principles to which no one could reasonably reject.3

To some contractarians such as Peter Carruthers, it is implied that only those who have rational capacities (which are needed to see oneself as a part of a contract) can be benefited by such a contract, and, therefore, that only rational agents would be protected by contractarianism.4 However, this is not automatically implicit in contractarianism. Those who participate in a contract can decide to protect others. And we have seen that we have strong reasons to do so in the case of nonhuman animals. Moreover, we could only accept a position like that of Carruthers if we accept a contractarian approach such as the one Hobbes defended, which does not consider fairness. However, if we accept the approach that contemporary contractarians have defended, we couldn’t accept a position in which only rational agents, or only the powerful, were protected. We would have to to examine under impartial conditions whether a principle is acceptable or not. If we would accept the principle from an impartial view, ignorant of what our own circumstances would be, then that principle is legitimate.

It is arbitrary to think that this impartial view applies only to human beings. True impartiality requires us to consider what would happen to all sentient (conscious) beings. Therefore, if we did not know which type of sentient being we would be, e.g., a human or a cow, we would certainly reject the speciesist discrimination that nonhuman animals currently suffer. This was pointed out in the 70s by Donald VanDeVeer,5 and has been stressed, in particular, by contractarian theorist Mark Rowlands.6

Hence we can conclude that contemporary contractarianism, like other ethical theories, is incompatible with the moral exclusion of nonhuman animals, and at odds with speciesism. As we have seen in the case of Peter Carruthers, there are speciesist positions that have been defended by an appeal to contractarianism. But contractarians need not accept such views, which entail assuming an old version of contractarianism (such as that of Hobbes) that most people find unacceptable nowadays.

Further readings

Arneson, R. (2002) “The end of welfare as we know it? Scanlon versus welfarist consequentialism”, Social Theory and Practice, 28, pp. 315-336.

Barry, B. (1989) Theories of justice, Berkeley: University of California Press.

Dworkin, G. (2002) “Contractualism and the normativity of principles”, Ethics, 112, pp. 471-482.

Gauthier, D. (1986) Morals by agreement, Oxford: Oxford University Press.

Gauthier, D. (1990) Moral dealing: Contract, ethics, and reason, Ithaca: Cornell University Press.

Norcross, A. (2002) “Contractualism and aggregation”, Social Theory and Practice, 28, pp. 303-314.

Pateman, C. (1989) The sexual contract, Stanford: Stanford University Press.

Pettit, P. (2000) “A consequentialist perspective on contractualism”, Theoria, 66, pp. 228-236.

Rawls, J. (1993) Political liberalism, New York: Columbia University Press.

Reibetanz, S. (1998) “Contractualism and aggregation”, Ethics, 108, pp. 296-311.

Scanlon, T. M. (2000) “A contractualist reply”, Theoria, 66, pp. 237-245.

Vallentyne, P. (ed.) (1991) Contractarianism and rational choice, Cambridge: Cambridge University Press.

Wenar, L. (2003) “What we owe to distant others”, Politics, Philosophy and Economics, 2, pp. 283-304.


1 Hobbes, T. (1651) Leviathan, or the matter, forme & power of a common-wealth ecclesiasticall and civill, London: Andrew Crooke [accessed on 10 December 2013].

2 Rawls, J. (1999 [1971]) A theory of justice, rev. ed., Cambridge: Harvard University Press.

3 Scanlon, T. (1998) What we owe to each other, Cambridge: Belknap Press of Harvard University Press.

4 Carruthers, P. (1992) The animal issue: Moral theory in practice, Cambridge: Cambridge University Press.

5 VanDeVeer, D. (1979) “On beasts, persons and the original position”, The Monist, 62, pp. 368-377.

6 Rowlands, M. (2009 [1998]) Animal rights: Moral, theory and practice, 2nd ed., New York: Palgrave Macmillan.