Responsive Reasons in Normative Ethics

This dissertation leverages recent developments in fittingness to make progress in fundamental issues in moral philosophy. I argue that fit-related reasons for action---\textit{responsive reasons}---have great theoretical utility in defending nonconsequentialist ethics. They draw a sharp boundary between consequentialist and nonconsequentialist theories. They constitute the motives that confer moral worth. They explain why it is wrong to kill innocents even to prevent more killings.