At her paper at the Rocky Mountain ethics conference, Judith Jarvis Thomson discussed various accounts of the metaphysics of harm. Somewhat surprisingly, she accepted the following equivalence.

• A harms B iff A causes B to suffer a harm.

Even more surprisingly, she defended this by saying it was a general claim about how causal verbs work. But this isn’t at all how causal words work. Compare this claim.

• A breaks B’s window iff A causes B’s window to be broken.

Here’s a counterexample to that. A is a speaker at a philosophy conference. She makes an outrageous claim about the semantics of causal verb. This so upsets C that he storms out of the room, and in his anger punches the window of B’s car. The window breaks. Now it seems clear that A has caused B’s window to be broken, with of course some help from C, but A didn’t break B’s window.

So I was thinking that the biconditional about harming and causing harms would also be false. And I was thinking that cases of indirect causation, like this one, would be examples of when they were false. But when I wrote up the case, it became less clear.

So question: In the case just described, where C breaks B’s window, does A harm B? It’s clear that A does cause B to suffer a harm. And if pushed I would say that A didn’t harm B – that only C harmed B. But my intuitions are nowhere near as clear as I hoped. What do you think?