In this lecture I shall offer to make clear, deeply grounded, objective sense of a certain contrast: I call it the contrast between positive and negative instrumentality, and it shows up in ordinary speech in remarks about what happens because a person did do such and such, as against what happens because he did not. The line between positive and negative instrumentality lies fairly close to some others which are drawn by more ordinary bits of English. For instance, the difference (...) between positive and negative instrumentality in someone’s dying is cousin to the difference between killing a person and letting him die. The latter distinction has the advantage of being already encoded in plain. (shrink)

Judith Jarvis Thomson; Killing, Letting Die, and The Trolley Problem, The Monist, Volume 59, Issue 2, 1 April 1976, Pages 204–217, https://doi.org/10.5840/monis.