Abstract

In this dissertation I argue for two factual claims and a normative conclusion on the basis of those claims. The first factual claim is that the faculty hypothesis in one of its three guises has effected the shape of Anglo-American moral theories. The second factual claim is that there is not, to date, any clear and convincing evidence that the faculty hypothesis is true. The normative conclusion based on these two premises is that if we want a practically applicable moral theory we ought not to rely so heavily and uncritically on the faculty hypothesis in our moral theorizing as we have in the past. ;Chapters two and three address the first claim. Chapter two does so in a broad historical context, and chapter three does so with respect to Locke and Rousseau in particular. Chapter four addresses the second claim, and in a survey of some work in neural anatomy, cognitive and emotional development and lesion studies finds no clear evidence for the faculty hypothesis. Chapter five examines Rawls' attempt to resolve the dispute between Locke and Rousseau on the level of moral theory. Chapter six looks at Hume's attempt to do the same thing, but on the level of psychology. I find both these approaches to be unsatisfactory in the end, but not without important redeeming features. ;In the last chapter I take the case of a research hospital institutional review board's treatment of a specific protocol as a test case for the psychological assumptions and moral theories of the Rawlsian and Humean theories. I find the Rawlsian psychological assumption to be untenable, but his normative standards to be very helpful. I find the Humean psychology far more realistic, and also find that he offers some useful insight into how to deal with the actual situation. I conclude this chapter with a brief discussion about what a more acceptable moral psychology and moral theory might look like