To expose a shortcoming in the study of logic and ethics, Hintikka (1999) draws an analogy that takes logic to have been taken over by a “defensive attitude”: the avoidance of logical mistakes. A similar attitude, he claims, is prevalent in ethics, which approaches the subject from the perspective of the study of moral mistakes. He uses a distinction between definitory and strategic rules to examine this shortcoming and its consequences in logic. Hintikka does not examine the other side of his analogy, namely the distinction in theories of ethics, however. In this paper we examine those ethics-related aspects of his analogy that have previously gone unnoticed. They are: (1) the possibility of introducing and applying a novel distinction to ethics to distinguish two fundamentally different kinds of ethical rules, the definitory and the strategic rules; (2) the use of these rules to illustrate a fundamental shortcoming in the modern conception of normative ethics; (3) the possibility to separate two conceptions of ethics from each other based on the type of rules that they aim to formulate; (4) the radically different yet unexplored idea of treating ethical rules as strategic rules; and (5) taking Peirce’s habits as strategic rules of interaction at work in both ethical and logical conduct.