A Philosopher's Dozen
Selections from the writings of Stephen Yablo
Excerpt from "Advertisement for a Sketch
of an Outline of a Proto-Theory of Causation"
A COUPLE OF THOUSAND YEARS BEFORE HUME made the remark that inspired the counterfactual theory of causation, Plato said something that bears on the principal problems for that theory. What Plato said, or had Socrates say, is that a distinction needs to be drawn between “the cause” and “that without which the cause would not be a cause” (Phaedo, 98e).
This sounds like the distinction between causes and enabling conditions: conditions that don't produce the effect themselves, but create a context in which something else can do so; conditions in whose absence the something else would not have been effective. And, indeed, that is what Plato seems to have had in mind. In the dialogue, Crito offers Socrates a chance to escape from prison; he refuses. The cause of his refusal is his judgment that one should abide by the decision of a legally constituted court. But it is facts about Socrates's body that allow the judgment to be efficacious. “If he had not had this apparatus of bones and sinews and the rest, he could not follow up on his judgment, but it remains true that it is his judgment on the question that really determines whether he will sit or run” (Taylor 1956, pp. 200-1).
Socrates’s bones and sinews are factors such that if you imagine them away, the cause (Socrates's judgment) ceases to be enough for the effect. Are there conditions such that a cause ceases to be required for its effect, if you imagine them away?
Yes.
ROCK
Billy and Suzy throw rocks at a window. Suzy's rock gets there first and the window breaks. Had Suzy not thrown, the window would have broken anyway, thanks to Billy's rock.
The effect does not depend simpliciter on Suzy's throw. (ROCK is thus a counterexample to the counterfactual theory of causation, which says that an event c causes an event e only if e would not have occurred, had c not occurred.) But e does depend on Suzy's throw, holding fixed the fact that Billy's rock never came into contact with the window.
Apparently there are two kinds of factors "without which the cause would not be a cause.” On the one hand, we have enablers: facts G such that the cause c would not have been enough for e, had G not obtained. On the other we have what might be called ennoblers: facts G such that the cause c would have not been required for e, had G nor obtained. Enablers make a dynamic contribution. They help to bring the effect about. What an ennobler contributes is just a raising of status. Suzy’s throw is elevated from something that just happens to something that had to happen, if the window was going to break.
What about a modified counterfactual theory which links causation to the existence of an ennobler—a fact G such that e depends on c holding G fixed? If the original counterfactual theory made it too difficult to be a cause, the revised theory makes it too easy. Consider an example of Hartry Field's.
BOMB
Billy puts a bomb under Suzy's chair; later, Suzy notices the bomb and flees the room; later still, Suzy has a medical checkup (it was already arranged) and receives from her doctor a glowing report.
Field intends this as a counterexample to transitivity, and so it is. The bomb is a cause of the fleeing is a cause of the glowing report; the bomb is not a cause of the glowing report. But it is also an example of Plato's distinction. The glowing report does not depend simpliciter on Billy’s planting the bomb. But it does depend on it modulo the fact that Suzy's chair explodes. Holding the explosion fixed, Suzy would not have been healthy unless she had moved away, which she would not have done, had she not noticed the bomb, which would not have been there to notice had it not been put there by Billy. It seems on the face of it insane to credit Suzy's good health to the bomb; she is healthy despite the bomb, not because of it! And yet her health depends on the bomb modulo a pretty natural fact.
The structure of the case is this. E was going to happen anyway, when c comes along to threaten it: to put its existence in jeopardy. Of course, putting the effect in jeopardy is not all c does, or it would not even resemble a cause. It also rescues e from the jeopardy. C threatens e with one hand, and saves it with the other. The effect needs c to counter the threat G that c itself has launched.
Now, should e be grateful to c for blocking with one hand a threat it launches with the other? Of course not. There is a word for that kind of inappropriate gratitude. You might remember it if I quote from a website on the topic: "In the summer of 1973, four hostages were taken in a botched bank robbery at Kreditbanken in Stockholm, Sweden. At the end of their captivity, six days later, they actively resisted rescue. They refused to testify against their captors, raised money for their legal defense, and according to some reports one of the hostages eventually became engaged to one of her jailed captors."
Stockholm Syndrome is a term for the gratitude hostages feel toward captors who help them with problems brought on by the captivity. To give the bomb causal credit would be the metaphysical equivalent of Stockholm Syndrome. There is nothing wrong with gratitude for actions taken against a threat that has already been launched: not even if the action is taken by the one who launched it. If your kidnapper takes pity on you and gets you a Mars bar, there is no requirement of flinging it back in his face. But suppose your kidnapper says, "I appreciate that you are grateful to me for various particular acts of mercy. But still I am hurt. Where is the thanks I get for the action that occasioned these mercies, that is, the kidnapping?"
That remark you should fling back in his face. •
Photograph: Jon Sachs