The Additive Fallacy

Abstract

Much moral philosophy is concerned with defending or attacking the moral relevance of various distinctions. Thus consequentialists disagree with deontologists, and deontologists disagree among themselves, over whether any moral weight should be given to such distinctions as that between what one does and what one merely allows, or to the distinction between what one intends as a means, and what one merely foresees as a side-effect, and so on. Similarly, there is disagreement over the moral relevance of such factors as the motive of the agent, the consequences of a given act, or the guilt of those who may be harmed. (On some matters, perhaps, there is widespread agreement: there seems to be a contemporary consensus, e.g., that skin color is of no intrinsic moral importance.) Such discussions, of course, are of intrinsic theoretical interest, for as moral philosophers we would like to have adequate beliefs about which factors (and which distinctions) are morally relevant.' They are also, furthermore, of some practical importance, for we appeal to such factors in assessing the moral status of actions in difficult and controversial cases, and in order to explain and defend our judgments. Obviously, however, such practical applications are of limited value until we have determined whether or not a given distinction actually merits being given moral weight. But how are we to settle this? How can we defend, or attack, claims involving the moral relevance of different distinctions? A very common form of argument proceeds by offering a pair of cases that differ only in terms of the factor in question.2 If we judge the