Yesterday, we saw that in Japan, blood types have taken the place of astrology—if your blood type is AB, for example, you're supposed to be "cool and controlled".

So suppose we decided to invent a new word, "wiggin", and defined this word to mean people with green eyes and black hair—

      A green-eyed man with black hair walked into a restaurant.
   "Ha," said Danny, watching from a nearby table, "did you see that? A wiggin just walked into the room. Bloody wiggins. Commit all sorts of crimes, they do."
      His sister Erda sighed. "You haven't seen him commit any crimes, have you, Danny?"
   "Don't need to," Danny said, producing a dictionary. "See, it says right here in the Oxford English Dictionary. 'Wiggin. (1) A person with green eyes and black hair.' He's got green eyes and black hair, he's a wiggin. You're not going to argue with the Oxford English Dictionary, are you? By definition, a green-eyed black-haired person is a wiggin."
   "But you called him a wiggin," said Erda. "That's a nasty thing to say about someone you don't even know. You've got no evidence that he puts too much ketchup on his burgers, or that as a kid he used his slingshot to launch baby squirrels."
      "But he is a wiggin," Danny said patiently. "He's got green eyes and black hair, right? Just you watch, as soon as his burger arrives, he's reaching for the ketchup."

The human mind passes from observed characteristics to inferred characteristics via the medium of words. In "All humans are mortal, Socrates is a human, therefore Socrates is mortal", the observed characteristics are Socrates's clothes, speech, tool use, and generally human shape; the categorization is "human"; the inferred characteristic is poisonability by hemlock.

Of course there's no hard distinction between "observed characteristics" and "inferred characteristics". If you hear someone speak, they're probably shaped like a human, all else being equal. If you see a human figure in the shadows, then ceteris paribus it can probably speak.

And yet some properties do tend to be more inferred than observed. You're more likely to decide that someone is hu...