In doing good  for others, we often provide certain benefits on a robust basis: we control for the provision of those benefits not just as things actually are but under any scenarios, some quite improbable, that satisfy certain conditions. Thus we enable others to enjoy our friendship or honesty or fairness, not just by acting in a friendly or honest or fair way, but in doing so with the robustness associated with acting out of friendship or honesty or fairness. This paper argues that things are different with doing evil to others and that this has important implications. It explains the Knobe effect in psychology. And it explains why people find the doctrine of double effect, and the principle of action and omission, attractive.