Categories versus natrual kinds

I wrote for 90 minutes this morning.

I'm working through the difference in meaning between a natural kind and a human-constructed category.

Clearly, what Bunge says with respect to "model thing" must be relevant here. Bunge states on page 122 that indicernables are represented by the same model things. This seems important for the idea of placing an order for an undetermined individual product. A person places an order for a model, not a thing.

Yet it does not capture the issue of categorization; in fact, Bunge acknowledges that "more sophisticated modes of representation" can be achieved through the use of categories, which he does not embrace (p. 121)

Model things are indicernables. Clearly, two if two people both have astrocytoma toumors, they are discernable, they will have different mass, different volume, different shape. The will be located in the heads of two different people. Yet, we get value from classifying them both as astrocytoma. The have enough in common that we can call them the same kind of thing. If fact, they are what bunge calls a "natural kind." This means that they share laws, which is the very reason that we want to classify them in the first place. So at least in this case, a natural kind seems very similar to a category. The point is that we cannot assign an attribute (with or without an ontic correlate) to a kind. A kind has all and only the properties that define it. That is, the kind is said to have the properties that all its member-things hold in common. So there can be a natural kind called "tumor" It has all the properties that the properties that are shared by all tumors. Likewise there is a natural kind called "Astrocytoma" and a natural kind called "Ganglioglioma" and a natural kind called "Oligodendroglioma." Clearly, the kind "tumor" has all the instances of Astrocytoma, Ganglioglioma, and Oligodendroglioma, and many others. However, we cannot assign an attribute to the kind "Astrocytoma" such as a "recommended treatment." A treatment can be recommended for each individual instance of an Astrocytoma tumor, however unless each one receives the same recommendation, it cannot be said to be an attribute of the kind.

This seems to be an important distinction between the natural kind "Astrocytoma" and the socially constructed category "Astrocytoma."