What is the good of selective conscientious objection? Why is it a good? And for whom is it a good? These questions may seem to be a strange way to open a chapter reflecting on the morality of selective conscientious objection for at least two reasons. In the first place, we think of conscientious objection as a negative way of responding to evils rather than as a good to be attained or striven for. The context for principles and decisions in this matter is violent and coercive. That which is to be decided is participation or nonparticipation in war, the most sanguinary and destructive of human activity. That which impels to decision is the legal demand, backed by the coercive power of the state, that all those judged to be qualified by the state must, if called, participate in this activity which requires the doing and suffering, the awaiting and the threatening of great evils. Note here that I am speaking of evils in a pre-moral sense which does not imply that a negative answer has already been given to the question of whether war in general or any given war is morally justifiable but which does bring with it a strong need for moral justification.