This dissertation, a study at the intersection of ethics and cognitive science, addresses the methodological question of whether empirical inquiry into how people make moral judgments and decisions has substantive consequences for moral philosophy.

In the first chapter I introduce concerns about the ways in which nonconscious and idiosyncratic psychological processes influence our moral judgments. As we have no introspective access to these processes, we must turn to empirical inquiry. We must also take care to preserve the essentially normative element of moral theory.

Chapter two describes a popular argument to the effect that theories of mental architecture have consequences concerning moral cognition. I suggest that this argument opens an underappreciated possibility: we might also treat those entailments as predictions of cognitive science that can be used to evaluate claims within cognitive science. Moral philosophers may then be in a unique position to test these entailments, and so generate feedback to debates about mental architecture.

Chapter three focuses on the work of moral philosopher John Rawls, whose famous method of reflective equilibrium bears comparison to a research program in cognitive science. I argue that this descriptive psychological aspect is in fact essential to Rawls' project, and on that basis defend Rawls from allegations of methodological conservatism. I suggest that the descriptive aspect enables reflective equilibrium to meet the reasonable demand that any moral theory be psychologically realistic.

In chapter four I discuss the moral self/other asymmetry. Empirical evidence suggests that we tend to evaluate identical actions differently depending on whether they are done by ourselves or others. This presents a challenge to the widely accepted view that moral judgments must be universalizable . I offer a psychological hypothesis to account for this data, which may make some progress toward preserving universalization.

In chapter five I consider the challenge of self-alienation created by our growing knowledge of these nonconscious processes. I argue for a model on which conscious moral reflection is aimed at selecting one's own psychology, conceived as a character playing roles in coherent narratives. This approach offers a compelling way of reintegrating the self through descriptive-normative collaboration.