Moralising is a venerable last resort strategy. The ancient Melians presented the Athenian generals with a splendid example when in a particularly tight corner. In our Western philosophical tradition moral rhetoric is often couched in the form of reasons for action either external to preference and desire (eg. Kant) or internal to the agent''s calculus of desire (e.g., Hume, Gauthier). A third tradition dismisses such rhetoric as the last recourse of the weak (e.g., Aristotle, Nietzsche) whereas a fourth calls for (...) an examination of the social context (e.g., Socrates, Marx, Wittgenstein, Habermas). This paper reports on an experiment which throws some empirical light on these debates and offers a surprising twist to the interpretation of the Melians'' plea. (shrink)