Taking a cue from an interesting discussion between Jonathan Schaffer and David Sosa, let’s say that there are three positions to hold about knowledge: eliminativism, which maintains that there are no knowledge relations; monism, which holds that there is one knowledge relation; and pluralism, which holds that there is more than one knowledge relation.
There is a danger, however, that pluralism is a fairly trivial thesis (so long as eliminativism is rejected). It looks as if it is confirmed by the fact that people use the term ‘knows’ and its variants in a variety of ways. Sometimes the term takes a person or thing as its complement, as in “Bo knows jazz.” And, as is well-known, there are other uses as well.
So suppose we restrict our three theories to sentences involving that-clauses as complements of ‘knows’. That helps some, but everyone already knew that there are competent uses of ‘knows that’ that are not factive, for example. “I just knew the Yankees were going to lose two years ago, but they took a year longer than I expected.” Etc.
Here’s what we might try. Distinguish between that-clause examples that can be explained away in terms of other concepts, and those that can’t. In the case above, we explain away the use of ‘knew’ in terms of psychological certainty. Among the remaining cases, the pluralist holds, there will be more than one relation found.
A niggling worry remains, however. Consider Ernie Sosa’s distinction between animal and reflective knowledge. Is this a version of pluralism? Or just two different kinds of the same monistic relation? I suspect Ernie would insist on the latter, but I’m not sure how to sustain this view. Perhaps as follows? Don’t multiply senses beyond necessity, so if one can model different usages of a term without ambiguity, don’t posit it. But perhaps there are other ideas?