You can, though it's usually useless; but it also depends on whether that subcategory is always necessarily empty or it happens to be empty now but in principle it could be non-empty.
(But it's still a fallacy of grey: even if all academic disciplines were, in fact, BS disciplines, some disciplines may still be less BS than others.)
Another month has passed and here is a new rationality quotes thread. The usual rules are:
And one new rule: