While at Brown, a quite interesting issue came up a couple of times, both during one of the sessions and also in converstation, that I thought would be good to pursue here. A common assumption is that what divides epistemologists with my sort of inclinations in the theory of justification from those such as Goldman, Nozick, Sosa, Greco and the like has something to do with the necessity, and perhaps a priority, of epistemic principles. While it is true that internalists such as Chisholm view epistemic principles in this way, I have never quite been able to see why this issue would be seen as a dividing issue between internalists and externalists.
Here’s why I’m perplexed by the assumption.
Every theory of justification will generate some necessarily true epistemic principles, so long as the theory itself is taken in the usual philosophically robust sense, i.e., is taken to be necessarily true if true at all. This point holds for internalist and externalist theories alike. But the idea is supposed to be that all the principles of a certain kind of theory have to be necessary. I’m inclined to think there isn’t a prayer for an argument to this conclusion unless we’re thinking of access internalism here. In such a case, the principles that guide belief formation would need to be a priori, and perhaps there is some way to get from a prioricity to necessity in this case (even though we can’t in general draw such a conclusion).
Take, for example, classic bayesian coherentism, where probabilistic coherence is necessary for justification and updating occurs by conditionalization. Presumably, conditionalization is regarded as a necessary truth, but not any specific principle that ties a particular new piece of knowledge (to speak loosely) to updated degrees of belief (i.e., more specific principles that play an appropriate role in explaining the state transitions in question).
But maybe there is some argument I haven’t thought of which ties a denial of externalism to the idea that epistemic principles have to be necessarily true if true at all.