The Rationality of Dispositions and the Rationality of Actions: The Interdependency Thesis1

Anita M. Supersona1

a1 University of Kentucky


I defend the Interdependency Thesis, according to which rational evaluations of dispositions and actions are made in light of each other. I invoke a model of rationality that relies on various levels of consistency existing between an agent's reasons for adopting a moral disposition, the argument for the moral theory she endorses (relying on the Kantian notion that all persons are equal in humanity), her desires, disposition, and choice to be a moral person as reflected in the maxim she adopts. The Interdependency Thesis shows that we do not need to demonstrate the rationality of every morally required action in order to defeat scepticism fully.


1 I dedicate this article to the memory of my younger brother, Tom, who passed away after a valiant fight against Hodgkin's disease lasting over six years. He taught everyone who knew him never to give up in any pursuit, and to go on with life and relish its pleasures even in the face of deep sorrow.

I thank David Copp, Ann Cudd, Russ Shafer-Landau, two anonymous referees for Dialogue, and the Philosophy Department at the University of Kansas for helpful comments on versions of this article.