 ‘Tree’ is a natural kind term. As such, it is plausible to suppose that this term’s primary semantic function is that of predicating membership in the kind T to which all trees belong. But suppose that there is no such kind T. In this case, the general term ‘tree’ would have no semantic value, since there simply would be no such property as that of belonging to T. As a consequence, Brueckner’s premise B* would express no proposition and would have no truth value, since the term ‘tree’ would make no semantic contribution to what is said by B*. Thus, in order for premise B* to express a truth, there must be a natural kind T to which all trees belong, and so Brueckner’s claim that B* can be true even if there are no trees seems doubtful.