Empirical psychology and its effect on natural moral realism

Abstract

I argue that empirical research can have important implications for various metaethical theories. I take an area of recent psychological interest, moral judgement-making, and show how current psychological research affects Peter Railton’s naturalist moral realism in particular. I first outline Railton’s naturalism and show that it is a viable metaethical theory that is amenable to psychological research. In particular, I outline Railton’s conception of ‘idealised agents’ and their relationship to actual agents, which is important for his naturalism. I then consider G.E. Moore’s Open Question Argument and Horgan and Timmons’ Moral Twin Earth argument, which try to show that various forms of naturalism cannot work. I demonstrate that Railton’s naturalism can avoid the arguments for reasons that lay it open to empirical resting. I then consider Jonathan Haidt’s psychological argument that we do not typically make moral judgements rationally, but through emotionally-based intuitions. As Railton’s naturalism depends greatly on rationality, this might be a problem. However, Haidt does not show that we should make moral judgements non-rationally, nor that rationality is typically unimportant in moral judgementmaking. Railton must take greater note of non-rational factors, but psychological research on intuitions may actually support his naturalism. I next use R.J.R. Blair’s work to show that psychopaths cannot make genuinely moral judgements. Railton implies that they can, but the empirical evidence is against him. It also shows that the psychopath’s problem arises from an emotional deficit rather than from a rational one, and that we cannot make moral judgements without certain non-rational powers. I argue that the psychopath thus creates problems for Railton’s naturalism, because it raises difficulties for the relationship between actual agents and idealised agents. I end by looking at what other metaethical theories can profitably use empirical research