RELEVANCE
In a good argument, we present statements that are true in order to offer support for some conclusion. One way to depart from this ideal is to state things that are true themselves, but have no bearing on the truth of the conclusion.
We might wonder why irrelevant remarks can have any influence at all. The answer is that we generally assume that a person’s remarks are relevant, for this is one of the conditions for smooth and successful conversation (as Grice pointed out in his rule of Relevance, discussed in Chapter 2). That it is possible to exploit people by violating this natural assumption is shown in the following passage from The Catcher in the Rye.
The new elevator boy was sort of on the stupid side. I told him, in this very casual voice, to take me up the Dicksteins’. . . . He had the elevator doors all shut and all, and was all set to take me up, and then he turned around and said, “They ain’t in. They’re at a party on the fourteenth floor.”
“That’s all right,” I said. “I’m supposed to wait for them. I’m their nephew.” He gave me this sort of stupid, suspicious look. “You better wait in the lobby, fella,” he said. “I’d like to—I really would,” I said. “But I have a bad leg. I have to hold it in a certain position. I think I’d better sit down in the chair outside their door.” He didn’t know what the hell I was talking about, so all he said was “oh” and look me up. Not bad, boy. It’s funny. All you have to do is say something nobody understands and they’ll do practically anything you want them to.1
