Edmund Gettier passed away last month. Gettier was best known for a short 1963 article on epistemology, which set off whole new lines of thought. He doesn't get on lists of "greatest philosophers of [specific period or country.]" He is too much of a one-trick pony for that. But: what a trick! Since Plato's time, "justified true belief" or some quite similar phrase has been taken as a sensible definition of Knowledge. Gettier's paper made the case that this doesn't work. There are lots of situations in which someone can have a belief that is both justified and true, but in which understanding the whole situation that makes it so will cause us to doubt, or outright to deny, that the situation deserves the title "knowledge." I won't explain his argument now, but will assume it as a given for the following that he made his point. Does it follow we are bound to adopt some other definition? We could just say, in a Wittgensteinian fashion,...
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One issue raised by the tracking theory of knowledge discussed in yesterday's post is "epistemic closure." Epistemic closure is a property of belief systems that is generally considered a good thing. Specifically, a belief system is said to be "closed" if and only if we can say that whenever a subject (S) knows a proposition (p), and S also knows that P implies q, then S knows q. If I know that today is Sunday, and I know that this implies that yesterday was Saturday, then I know that yesterday was Saturday. In examples like yesterday-was-Saturday, closure is strongly intuitive. But the standard view of the consequences of the tracking theory is that accepting it entails the abandonment of closure as a premise. Consider the "fake barns" scenario. I'm driving through a neighborhood where some of the locals delight in creating fake paper mache barns that look quite realistic from the road. I don't know about the local custom and, when I...
There is an old theory of knowledge known as the JTB view: the view, that is, that knowledge is "justified true belief." Edmund Gettier gets a lot of credit for weakening the hold of JTB upon conventional wisdom, in his brief article of 1963 in the journal ANALYSIS, arguing that there are cases in which all three circumstances are met, but which one wouldn't ordinarily speak of as "knowledge." Some people believe Gettier gets more credit than he deserves. Alvin Plantinga has written: According to the inherited lore of the epistemological tribe, the JTB [justified true belief] account enjoyed the status of epistemological orthodoxy until 1963, when it was shattered by Edmund Gettier... Of course there is an interesting historical irony here: it isn't easy to find many really explicit statements of a JTB analysis of knowledge prior to Gettier. It is almost as if a distinguished critic created a tradition in the very act of destroying it. ...