 There are certain kinds of counter-example that Wiggins does not discuss in print. There might, for example, be a sword-stick, which has its blade removed and the inside of the cane filled with resin, so that it ceases to be a sword but remains the same walking stick. Walking stick and sword are perfectly good concepts for picking out objects, if any artefactual terms are, and, on pain of excessive artificiality, a sword-stick is both a sword and a walking stick. This kind of example does not appear to occur amongst natural objects, but, as a sword-stick is a perfectly good reidentifiable object, this fact about natural objects would seem to be a contingent truth about them. Of course, it is not an accident that nature works that way, but neither is it a conceptual requirement. Wiggins’s original proof was a priori, and it should allow no exceptions. Wiggins’s response to this example (in personal communication) is that the sword-stick ceases to exist when it loses its ability to function as a sword and is replaced by a walking stick. But this response too is ad hoc. It embodies the principle that if anything is both an F and a G, where F and G are normally ordinary sortals, then it is really an F/G and ceases to exist if it loses either its F or its G features and is replaced by something that is either just an F or just a G.