‘Is’,‘Ought’ and Moral Realism: The Roles of Nature and Experience in Practical Understanding

This essay maintains that the logical distinction between ‘is’ and ‘ought’ does not amount to a dichotomy between the natural order and the moral, or between speculative knowledge and practical. This essay thus clarifies an important and often misunderstood aspect of the natural law theory advanced by the Grisez School. While affirming the logical distinction of ‘is’ from ‘ought’, this essay attempts to argue that the principles of the moral order have a basis in human nature insofar as human nature delimits the parameters of what is fulfilling for human persons. Furthermore, it is through the experience of one’s nature that one inductively grasps by a non-inferential insight the practical principles whose integral directiveness leads one to human fulfillment. The non-practical awareness of factual data one grasps in experience and which ground such a non-inferential practical insight is distinct from and more basic than reflexive, propositional, speculative knowledge (‘speculative knowledge proper’). Thus, practical understanding supposes some non-practical knowledge, although the non-practical knowledge supposed differs from speculative knowledge as ordinarily understood. Still, while the understanding of practical principles does not presuppose speculative knowledge proper, such speculative knowledge does contribute to practical reasoning in significant ways by supplying content crucial for adequate deliberation.