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. (shrink)