Wolfgang Schwarz

Discoveries merely about concepts

Okay. Here are some thoughts on a talk Frank Jackson gave last week on Williamson on thought experiments.

The question is what Gettier discovered in his famous article. According to Frank, he revealed a fact about our concept 'knowledge': that it is not the same as our concept of justified true belief. According to Williamson, Gettier has revealed a fact about knowledge itself: that it is not justified true belief. A discovery merely about our concepts, Williamson says, "would show little of philosophical interest"; it would be "of significance primarily to theorists of concepts, not to epistemologists". For "the primary concern of epistemology is with the nature of knowledge, not with the nature of our concept of knowledge". (All of these are from p.206 of The Philosophy of Philosophy.) Frank disagrees. He thinks that results about the key concepts of a discipline are quite important to that discipline.

Setting aside the silly question of what is of philosophical interest -- who is right about Gettier's discovery? Has he revealed a fact about knowledge or about 'knowledge' (or both)?

I suppose finding out that knowledge is not justified true belief is to find out that one thing, X, is not identical to another thing, Y. Here the two things are properties -- classes of possible individuals perhaps, or certain functions, or universals, or structures of universals. Whatever they are, they can be presented in different ways. (Otherwise the conjecture that knowledge is JTB would never have made much sense.) X can be presented as 'knowledge', but perhaps also as 'the most general factive mental state', or as 'undefeated justified true belief'. If properties are classes, X can also be presented as 'Y \ Z', where Z is JTB without knowledge. When Gettier discovered that knowledge is not JTB, maybe in some sense he discovered that Y \ Z is not Y. But the way this fact was presented to him (and by him) was crucial to his (and our) epistemic progress.

The same holds for almost every discovery. Discovering that Scott is the author of Waverley is more interesting than discovering that Scott is Scott; discovering that George Elliot is Mary Ann Evans is more interesting than discovering that George Elliot is George Elliot. Even if substituting co-refering names makes no semantic difference, it should be uncontroversial that it can make an epistemic difference: that "George Elliot is Mary Ann Evans" can answer a question or settle a dispute that "George Elliot is George Elliot" cannot. A statement's cognitive significance is not a function of what its constituents refer to.

In the other direction, different propositions often have the very same cognitive significance. "Scott is the author of Waverley", "'Scott' denotes the author of Waverley", and "{ Scott } is the set of authors of Waverley" arguably express different propositions. They are even about different things. (Only the last one is about a set.) Nevertheless, in many circumstances, they will answer the same questions and settle the same disputes. If King George understood elementary set theory and wondered who wrote Waverley, he wouldn't have dismissed the information that { Scott } is the set of authors of Waverley as irrelevant. He wouldn't have judged it to be "of significance primarily to theorists of sets". The information answered his question, albeit in a somewhat roundabout way.

So what was Gettier's discovery? As long as we take it for granted that our concept 'knowledge' picks out knowledge, there is, epistemically, no difference between discovering that knowledge isn't justified true belief and discovering that our concept 'knowledge' is not that of justified true belief. It's not that Gettier made both of these discoveries. The discoveries are one and the same.