Abstract Teaching professional ethics can take two very different forms, reflecting different fundamental assumptions about ethical rules, and leading to different problem-solving strategies in professional life. In this article I outline and contrast the two approaches, which I call the overriding principle approach and the moral dilemma approach. The first reifies ethical principles and underpins them with rationales drawn from moral philosophy. The second sees principles as templates of default options, which may or may not fit the facts of the case and the context in which decision must be made. In the moral dilemma approach, for instance, there is always some circumstance in which following particular moral rule would produce the wrong result. The CPA Code of Ethics has different advantages and disadvantages for teaching professional ethics depending on one's fundamental approach. Although its rhetoric and its ordering of rules seems to reflect the overriding principle approach, I argue that the Code is actually more relevant to the moral dilemma approach.There are two basic approaches to teaching ethics. This article presents these approaches and argues that they are based on fundamentally different ways of thinking about ethical dilemmas. I hope to show that the CPA Code of Ethics, including its associated decision-making model, has different advantages and disadvantages depending on which of the two approaches one adopts.How one teaches ethics depends upon the position one takes in the debate about whether there are any real ethical dilemmas or not. Most moral systems are based on the notion that there are no true ethical dilemmas. This position has been argued by philosophers as divergent as Aristotle (1985a), Aquinas (1954), Mill (1884), and Kant (e.g., a conflict of duties and obligations is inconceivable -- obligationes non colliduntur. (Kant, 1964, p. 24). Whatever their differences, these philosophers share the belief that it is possible to apply priority order to set of rules so that, when the rules are applied correctly, they completely resolve any ethical problem -- they leave no moral residue. In this framework, the mistaken belief that there are genuine dilemmas results from the fact that we have not learned the right principles to apply to case, and/or we have not learned to apply principles in appropriate priority order. I refer to this as the overriding principle approach because of its assumption that any apparent dilemma can be resolved by knowing and applying some principle that overrides other rules.The counter argument is that there are, in fact, genuine dilemmas that arise from the relevance of two or more ethical principles that are incompatible. Although one principle may have to be favoured over the other(s) to resolve the problem at hand, that resolution leaves the decision maker feeling justifiably unsatisfied (Williams, 1965). I refer to this as the moral dilemma approach.If one takes the overriding principle approach to the teaching of ethics, the task is to find fundamental rule, or to establish priorities among rules, that will transform what seem to be ethical dilemmas into technical problems. If one takes the moral dilemma approach, the task is to find the best fit between competing principles and the interests of different parties. Attention is focussed on the context, in the belief that context can always create situation in which following any particular rule is, in some sense, the wrong thing to do.The Cache of ArmsTo contrast these ways of thinking about ethical problems, and the consequences for the teaching of professional ethics, I present an archetypal ethical dilemma from Plato's The Republic (1937a). A man is visited by his neighbour who is going on trip; the neighbour leaves cache of arms for safekeeping, It is understood that the man will return the arms to the neighbour when he returns and asks for them. …