 How does the BTT handle our range of test cases? Consider, first, the standard form of the disjunction problem, the case of “X” meaning dog, rather than dog or fox-on-a-dark-night-at-a-distance. Since the latter is not apparently a natural kind, “X” cannot mean  that.[10]  Moreover, “X” means dog, rather than fox, because the only times the many foxes that S encounters can trigger “X1”s is on dark nights at a distance, where dogs trigger “X”s more consistently under a wider range of conditions.