Abstract
How exactly is accepting the bad side effects of good choices morally defensible? The best defense to date is by Joseph Boyle, John Finnis, and Germain Grisez and relies on the claim that bad side effects are unavoidable. But are they? Three accounts of why bad side effects are unavoidable—one by John Zeis, a second by Boyle, Finnis, and Grisez jointly, and a third by Boyle independently—are examined and rejected. Next, an alternative proposal which suggests bad side effects are always avoidable is also examined and rejected. Finally, an adequate account of why bad side effects are unavoidable is presented and defended. This defense relies on certain facts about the goods which human agents ultimately find fulfilling and about human agents’ attempts to instantiate those goods through various projects.