Abstract

Much recent work on Kant's argument that the Categorical Imperative is the fundamental principle of morality has focused on the gap in that argument between the conclusion that rational agents conform to laws that apply to every rational agent, and the requirement contained in the Universal Law of Nature formula.1 While it seems plausible – even trivial– that a rational agent, insofar as she is a rational agent, conforms to whatever laws there are that are valid for all rational agents, there does not appear to be any obvious route from this seemingly trivial claim to the controversial and substantive principle of acting only on maxims that one can at the same time rationally will every rational agent to act on.2 In what follows, I argue that the connection between rational agency and mere conformity to universally valid laws is not as trivial as it may seem. Many readers, I suspect, assume that Kant makes the trivial claim about rational agency because rational agency is rational, and being rational requires conforming to those laws that apply to all rational beings. For instance, this assumption is implicit in Onora O'Neill claim that "the interest of a Kantian universality test is that it aims to ground an ethical theory on notions of consistency and rationality rather than upon considerations of desire and preference."3 But, as I contend in what follows, the requirement to conform to laws valid for all rational agents is based on the fact that rational agency is, not rational, but agency. Indeed, the arguments leading to the first formulation of the Categorical Imperative rely on the idea of rational willing as a kind of causation in order to show this. And, as it turns out, the claim that the concept of causation contains the idea of conformity to universally valid laws is not a trivial claim.