Joseph LaPorte claims that some kind is a natural kind if it has significant “explanatory value”. For example, he claims that some thing being a polar bear explains why it looks the way it does and why it has certain behavioral and social properties (LaPorte, 2003, pg. 19). LaPorte’s proposal is not without its problems.
Intuitively, a book is a kind of thing. But it is not a natural kind of thing. However, a book being the kind of thing it is explains why one might be able to read it (or look at it), find it in a library, why it has two covers, etc. If all of this is true, a thing being a book has some kind of explanatory value and, therefore, meets LaPorte’s criteria of a natural kind. This is problematic because, as I’ve already stated, our intuitions strongly suggest that BOOK isn’t a natural kind.
It might be suggested that LaPorte has an avenue of escape. After all, he thinks that in order for something to be a natural kind, it must have significant explanatory value. However, he doesn’t say just what he means by “significant”. If Smith is interested in knowing all of the true propositions there are about books, the properties I mentioned earlier might be important for Smith to know; he might find them significant even when no one else does. So, without clarification from LaPorte on just what he means by “significant”, it isn’t clear that he can escape the uncomfortable conclusion that BOOK, and other kinds of things, are natural kinds given that they involve some level of explanatory value.
It’s possible that one could avoid this problem by suggesting that we set aside our intuitions about what counts as a natural kind. However, this seems like the kind of claim that should be argued for. Since no arguments to this effect are forthcoming (at least not in LaPorte’s work), it isn’t clear we should abandon our intuitions about what does (and does not) count as a natural kind and thus accept the conclusion that BOOK is a natural kind.
MLN


Nearly four years ago now, John published a post titled 




