This chapter argues that Audi's ethical theory lacks the kind of grounding found in the theories of Ross and Kant, contrasting the “principles” of Audi's theory with Kant's categorical imperative and Ross's prima facie duties. The categorical imperative, it argues, is not a “principle” in Audi's sense. Instead, it is an abstract formula that expresses the common element of all duties and reveals the nature of the (human) will. Kant's imperatives are thus internal to humans in a way that Audi's principles are not. Likewise, Ross's prima facie duties are not like Audi's principles: they presuppose a social world of interpersonal claims, serving to summarize general aspects of prior practical knowledge, and are thus internal to us. This chapter concludes that Audi's reading of Ross and Kant leaves his theory unable to explain our interest in ethics and why it is not an accident.
Keywords: ethics, Kant, Ross, duty, categorical imperative, moral principles