  How restricted should be the restriction of a restricted type theory? How many hairs must a bald man have no more of? An identity theorist would expect his toothache today to be very similar to his toothache yesterday. He would expect his toothache to be quite similar to his wife's toothache. He would expect his toothache to be somewhat similar to his cat's toothache. He would not be confident about similarity to an extra-terrestrial's pain. Even here, however, he might expect some similarities of wave form or the like.