Is Morality an Elegant Machine or a Kludge?1

In a passage in A Theory of Justice, which has become increasingly influential in recent years, John Rawls (1971) noted an analogy between moral philosophy and grammar. Moral philosophy, or at least the first stage of moral philosophy, Rawls maintained, can be thought of as the attempt to describe our moral capacity – the capacity which underlies “the potentially infinite number and variety of [moral] judgments we are prepared to make.” In order to describe that capacity, we must formulate “a set of principles which, when conjoined with our beliefs and knowledge of the circumstances, would lead us to make [the judgments we actually make] were we to apply these principles conscientiously and intelligently.” (Rawls 1971, 46) Citing Chomsky’s Aspects of the Theory of Syntax (1965), Rawls goes on to suggest that describing our moral capacity can be usefully compared to “describing the sense of grammaticalness that we have for the sentences of our native language. In this case the aim is to characterize the ability to recognize well-formed sentences by formulating clearly expressed principles which make the same discriminations as the native speaker.” (Ibid. 47) Though Rawls’ analogy between our moral capacity and a Chomskian grammar of our language was new and insightful, the project of describing our moral capacity – of finding a set of principles (or rules or definitions) which entail the potentially infinite number of judgments we actually make – has a history that goes back to Plato. In The Republic, Socrates asks Cephalus to provide an account of justice, and then challenges the