Jacques Maritain Center: Ethics Without God?

Is Ethical Naturalism Possible in Thomas Aquinas?

Saturday, July 19
Morning session
Anthony J. Lisska

The role of philosophical anthropology in the moral theory of Thomas Aquinas is a hotly debated issue in contemporary Aquinas studies. Proponents of what has been called "the New Natural Law" argue that an analysis of practical reason is sufficient to develop a theory of natural law fully compatible with the insights of Aquinas. Other philosophers question this method of analysis on the texts of Aquinas.

In this paper, I wish to probe what I take to be the metaphysical underpinnings of Aquinas's moral theory. The argument is fundamentally that Aquinas's moral theory is a second order inquiry based squarely on the metaphysical foundations of his natural kind ontology. The points to be made are the following:

The argument of this paper is that, in opposition to analytic philosophers like Myles Burnyeat, one can develop a persuasive dialectic for natural kind theory based on Aquinas's analysis of form. This depends upon the necessity of synthetic a priori causal properties. Secondly, if one takes these properties as fundamentally dispositional in mode, one has a method for transcending the limits of Moore's infamous naturalistic fallacy. The important claim to be articulated is a natural kind ontology of dispositional properties.

By discussing the role of form as a necessary condition for establishing synthetic necessary properties, which are dispositional in structure, one has a way of articulating and defending ethical naturalism in the moral theory of Thomas Aquinas.