An Old Comment on Definition and Inquiry

I came across an old comment that I had forgotten that I had written, in a comment thread that was partly on the subject of definition and inquiry; I thought at least part of it deserved its own blog post.

Definition in the strict and proper sense is in fact very difficult; achieving definitions that are both accurate and useful for a given set of purposes is often extraordinarily difficult, and is more often than not the end, rather than the beginning, of an investigation. This does not mean in the meantime that the names in question do not refer, only that the referring is imprecise (and may at times involve a confusion of more than one thing) and governed less by definition than by associated, and sometimes officially standardized, usages. For instance, suppose you are interested in studying jade. You do not need a definition of jade in order to begin studying jade; nor, from the fact that you cannot give a definition of jade at the beginning of your investigation, does it follow that you can just, for no good reason, start including milk among the things called 'jade'. And in studying jade, you start learning the things that are useful for definition: for instance, the fact that what seemed to be a single object, jade, turns out to be at least two, since nephrite (an amphibole) and jadeite (a pyroxene) are certainly not the same. As you continue looking into this, you might start uncovering puzzles about jade worth solving -- e.g., nephrite turns out not to be easily classifiable, since it can be either actinolite or tremolite (my understanding is that they are very similar and under fairly common conditions tend to change into one another over time). Thus, nephrite, which has a standard usage and therefore a meaning, turns out to be resistant to rigorous definition. This might lead in any number of directions in one's inquiry, e.g., to an attempt to come up with a better classification, or a rethinking of the inquiry itself.