Abstract

This dissertation is an attempt to show the intersection of two philosophical problems in moral philosophy with a theory of morality. The first problem is the so-called 'is-ought' problem. How are moral norms related to statements of fact, or, more broadly, theoretical knowledge? The relationship is problematic because of the need for moral norms to motivate agents: this motivational aspect of norms seems to conflict with a contemporary view of facts as 'static,' and unmotivating. ;Efforts have been made, however, to ground moral norms in 'dynamic,' or motivating facts. In this dissertation, I trace the origin of the 'is-ought' problem and address several attempts to overcome it. I then argue in that such attempts are problematic because they do not rely upon 'objective' reasons for action, which motivate from an impersonal standpoint. I further argue that such objective reasons could only be known foundationally, that is, as first principles. Because they are inherently motivating, I view such principles as principles of practical reason, and their apprehension as the work of practical reason. Thus, the grounding of moral norms is rational, but does not begin with a consideration of the facts, or with theoretical knowledge. ;This position on the difference between theoretical and practical reason has been stated by proponents of the Grisez-Finnis-Boyle interpretation of natural law theory. In the final chapter, I argue that this theory is substantially correct in its account of the principles of practical reason and their relation to moral norms.