Category Mistake

A category mistake, or category error, is a semantic or ontological error in which "things of one kind are presented as if they belonged to another", or, alternatively, a property is ascribed to a thing that could not possibly have that property. Thus the claim that "Most Americans are atheists" (untrue in 2009) is not a category mistake, since most Americans could be (contingently) atheists. On the other hand, "Most bananas are atheists" is a category mistake. This is because bananas belong to a category of things that cannot be said to have beliefs. Thomas Szasz argued that minds are not the sort of things that can be said to be diseased or ill because they belong to the wrong category and that "illness" is a term that can only be ascribed to things like the body; saying that the mind is ill is a misuse of words. Another example is the metaphor "time crawled", which if taken literally is not just false but a category mistake. To show that a category mistake has been committed one must typically show that once the phenomenon in question is properly understood, it becomes clear that the claim being made about it could not possibly be true.