 The act utilitarian seems unable to account for this fourfold distinction. It implies that I do wrong every time I fail to perform the optimal act, even when these suboptimal acts are very good. Because it makes the optimal obligatory and the suboptimal wrong, it appears to expand the domain of the forbidden, collapse the distinction between the permissible and the obligatory, and make no room for the supererogatory. If the optimal is already one’s duty, there appears to be no room for the supererogatory. By contrast, sanction utilitarianism does not appear to have these problems. It offers a distinct account of each category.