In response to:

How Do We Know What’s Moral? from the April 24, 2014 issue

To the Editors:

It’s a sad fact that if one lets a falsehood get repeated too often, it can become a familiar truth. In his review of David Edmonds’s Would You Kill the Fat Man? [NYR, April 24], Cass Sunstein says that the hypothetical case he calls “The Trolley Problem”—in which a bystander can throw a switch, thereby turning a trolley that is headed toward five people onto a track on which there is only one person—was introduced into the literature of moral theory by Philippa Foot, in an article by her entitled “The Problem of Abortion and the Doctrine of the Double Effect,” published in 1967. I presume that Mr. Sunstein got that piece of misinformation from Mr. Edmonds’s book. Goodness knows where Mr. Edmonds got it. (I haven’t read his book, so I don’t know.) But misinformation it is, since the case first appeared in an article by me entitled “The Trolley Problem,” published in 1985 in the Yale Law Journal.

Judith Jarvis Thomson
Department of Linguistics and Philosophy
Massachusetts Institute of Technology
Cambridge, Massachusetts

Cass R. Sunstein replies:

In her 1967 essay, Philippa Foot posited a case in which someone “is the driver of a runaway tram which he can only steer from one narrow track on to another; five men are working on one track and one man on the other; anyone on the track he enters is bound to be killed.” Foot wondered “why we should say, without hesitation, that the driver should steer for the less occupied track.” David Edmonds, whose book I reviewed, follows convention in treating Foot as the founding mother of trolleyology. But it was indeed Thomson, and not Foot, who named the Trolley Problem and developed it in the form in which it is widely discussed.