In the 1950's some prominent philosophers suggested a logical relation weaker than entailment between primarily descriptive statements and ethical conclusions. The paper revisits this suggestion. It examines four ways in which ethical statemnts can be supported by descriptions and evaluations. This provides a similarity bteween some kinds of reason-giving in ethics and familiar cases of logical inference, making it plausible to speak of a logic. The similarity however is limited, and the strength in ethics of descriptive reasons is never precise and always somewhat contestable.