Thursday, November 27, 2008

The more you know...

Some things sound like tautologies, but aren't. Here is one:

  1. The more you know, the less you are ignorant of.
Obviously, if you come to know p, you cease to be ignorant of p. But it may well be that coming to know p brings it about that you no longer know some things that you used to know. For, p might be a defeater for things you knew, or p might be a conjunction of unrepresentative cases that destroys some inductive argument you had (previously you knew that most mice have tails; but, completely by chance, over the past year, each day you've come across a different tailless mouse; now, you no longer know). So learning a new thing might make one cease to know a number of other things one used to know.

Is knowledge of p then a good thing, all things considered, or would one be better off not knowing that?


jawats said...

It seems to me that p may be knowledge about a thing. If learning p results in destruction of something else, say n, the one has learned something about n, namely that n may be eliminated by knowledge of p.

Mike Almeida said...


Can there be knowledge loss? Two cases:

(1) You discover that the proposition p that you earlier claimed to know is false.

If (1) is true, did you lose knowledge? Looks more like you did not. You thought you knew, but since one of the conditions on knowledge was not met (the truth condition), you never knew what you thought you knew.

(2) You discover that the justification (warrant, etc.) for p is defeated by new information q.

If (2) is true, did you lose knowledge? It looks again like one of the conditions for knowledge you thought obtained--viz. undefeated justification--in fact did not. You learn, for instance, that one of the inference rules you used in your justification of p was misapplied. The inference, you learn, is invalid.

It would be interesting and strange to claim nonetheless that you did know p on the basis of that invalid inference. Indeed, I think Plantinga would say you did know, since he doesn't allow that q defeats knowledge that p unless you discover q.