Wednesday, October 27, 2010

Knowledge Norms and Intuitions about Cases

Here's a boring thought experiment that doesn't demonstrate anything.
Smith burgled the house last night; Detective Stanley is investigating the crime scene. He acquires evidence sufficient for knowledge that the burglar came in through the window, but finds very little evidence about whether it was Smith or someone else who committed the crime.

Here are two intuitive verdicts that aren't in any tension at all:

  1. Stanley knows that the burglar came in through the window.

  2. Stanley would need to have more evidence in order for it to be appropriate for him to arrest Smith.

Everybody can accept these obvious claims. In particular, these obvious claims are in no tension with the knowledge norm of practical reasoning, which claims that p can be an appropriate reason for action for S if and only if S knows that p. It would be an anemic objection to the knowledge norm to point out that Stanley knows that the burglar used the window, but needs more evidence in order for it to be appropriate to arrest Smith. That the burglar used the window just isn't a strong enough reason to arrest Smith, so this case doesn't tell us anything about what is and is not a reason. So it doesn't tell us anything about knowledge norms.

The moral of the story is that claims about who knows what, and about what actions are inappropriate, are in general insufficient to refute the knowledge norm of practical reasoning. (So, mutatis mutandis, for the knowledge norm of assertion.)

When you look at the case given above, this moral is really obvious. But sometimes, I think, it's neglected. Jessica Brown, for instance, argues against the knowledge norm of practical reasoning by citing this case:
A student is spending the day shadowing a surgeon. In the morning he observes her in clinic examining patient A who has a diseased left kidney. The decision is taken to remove it that afternoon. Later, the student observes the surgeon in theatre where patient A is lying anaesthetised on the operating table. The operation hasn’t started as the surgeon is consulting the patient’s notes. The student is puzzled and asks one of the nurses what’s going on:

Student: I don’t understand. Why is she looking at the patient’s records? She was in clinic with the patient this morning. Doesn’t she even know which kidney it is? Nurse: Of course, she knows which kidney it is. But, imagine what it would be like if she removed the wrong kidney. She shouldn't operate before checking the patient’s records.

We have, as before, a pair of intuitive verdicts: one attributing knowledge, and another denying appropriateness of action. Brown considers this to be a counterexample to the knowledge norm of practical reasoning, but the case of the burglar shows that this cannot not enough. Just as the burglar argument was transparently invalid, because the burglar's use of the window wouldn't be sufficient reason for arresting Smith, Brown's argument is valid only on the assumption that the disease in the left kidney would be a sufficient reason for operating without checking the charts. But Brown has given us no reason to think that is so. It's entirely open to the defender of the knowledge norm to argue that knowledge of p is sufficient for p to be a reason, but that in this case, p isn't a good enough reason for action.

This strategy is always available. I think this shows that trading in intuitions about who knows what, and who ought to do what, is not a helpful strategy for evaluating knowledge norms.

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