Abortion is considered in relation to the doctrine of the double effect, which distinguishes between the intentions behind an action and consequences foreseen but not desired. This doctrine, often used to defend the position of the Catholic Church on abortion, is here rejected. Alternative distinctions are drawn, between what we do and what we allow to happen, and between the infringement of ‘positive’ and ‘negative’ duties. These distinctions are applied to the problem of abortion and to other moral dilemmas.