Robert Charles Koons

The “New Natural Law” Theory (NNL) of Germain Grisez, John Finnis, Joseph Boyle, and their collaborators offers a distinctive account of intentional action, which underlies a moral theory that aims to justify many aspects of traditional morality and Catholic doctrine. In fact, we show that the NNL is committed to premises that entail the permissibility of many actions that are irreconcilable with traditional morality and Catholic doctrine, such as elective abortions. These consequences follow principally from two aspects of the NNL. The first aspect is its distinctive version of the planning theory of intention, in which adopting the 'first-person perspective' of an agent is a sufficient, and not merely necessary, condition for determining the nature of his intentional action; this planning theory rests upon an implicitly Cartesian conception of human behavior, in which behavior chosen by an agent has no intrinsic “intentionalness” apart from what he confers upon it as part of his plan. The second aspect is the NNL's distinctive account of basic human goods' incommensurability, according to which there is no common factor shared by basic human goods that allows them to be comparatively ranked in any way that directs practical deliberation. The entailments of these two aspects of the NNL, we argue, amount to a reductio ad absurdum. Pace the proponents of the NNL account, we sketch an alternative hylomorphic conception of intentional action that avoids untoward moral implications by grounding human agency in the exercise of basic powers that are either (a) essential constituents of human nature or (b) acquired through participation in social practices. This conception of intentional action provides a stronger foundation for natural law theory.

Three-valued (strong-Kleene) modal logic provides the foundation for a new approach to formalizing causal explanation as a relation between partial situations. The approach makes fine-grained distinctions between aspects of events, even between aspects that are equivalent in classical logic. The framework can accommodate a variety of ontologies concerning the relata of causal explanation. I argue, however, for a tripartite ontology of objects corresponding to sentential nominals: facts, tropes (or facta or states of affairs), and situations (or events). I axiomatize the relations and use canonical models to demonstrate completeness.

This chapter argues that materialism is vulnerable to two kinds of epistemological objections: transcendental arguments, that show that materialism is incompatible with the very possibility of knowledge; and defeater arguments, that show that belief in materialism provides an effective defeaters to claims to knowledge. It constructs objections of these two kinds in three areas of epistemology: our knowledge of the laws of nature (and of scientific essences), our knowledge of the ontology of material objects, mathematical and logical knowledge. The chapter argues that these epistemological weaknesses place the materialist in a dialectically weak position in respect of ontological identity claims, since the materialist cannot know the causal powers or persistence conditions of material objects. It also argues that the materialist can provide no non-circular account of epistemic normativity. Anti-realist accounts of normativity are unavailable because normativity is already implicated in all intentionality. Moreover, materialists face a fatal dilemma in attempting to carry out an etiological reduction of teleological norms, since neither Humean nor anti-Humean accounts of causation yield defensible results.

The ancient puzzle of the Liar was shown by Tarski to be a genuine paradox or antinomy. I show, analogously, that certain puzzles of contemporary game theory are genuinely paradoxical, i.e., certain very plausible principles of rationality, which are in fact presupposed by game theorists, are inconsistent as naively formulated. ;I use Godel theory to construct three versions of this new paradox, in which the role of 'true' in the Liar paradox is played, respectively, by 'provable', 'self-evident', and 'justifiable'. I also construct in modal operator logic a paradox involving reflexive empirical reasoning. Unlike the paradox of the Liar, the paradox of reflexive reasoning does not depend on self-reference. ;I consider various solutions to the Liar paradox and evaluate how well these solutions cope with the paradox of reflexive reasoning. I then formalize the solution to the paradoxes which I favor: the indexical-hierarchical approach, first sketched out by Charles Parsons and Tyler Burge. In this solution, occurrences of the predicate 'true' in sentence-tokens are contextually relativized to levels of a hierarchy. Drawing also on some brief remarks of Bertrand Russell and Charles Parsons, I develop an account of the kind of schematic generality needed for this theory to be statable. ;Finally, I demonstrate that the principles shown to be paradoxical are in fact presupposed by contemporary game theorists in their reliance on the notion of common knowledge or, more precisely, mutual belief. I create novel analyses of and corresponding solutions to several recalcitrant puzzles within game theory, including the "chain-store paradox"