不気味の谷現象

Now, here’s the kicker, the real key to creepiness: essences don’t come in degrees. It’s part of the notion of essences that if a thing possesses an essence, it possesses it completely. In our ordinary, pre-theoretical ways of cognising animals, if we think of something as a dog, we are inclined to think of it as completely a dog, and if we think of something as a lizard, we are inclined to think of it as completely a lizard. Now, consider the example of a dog with a lizard’s head. According to the implicit logic of essentialism, such a creature must be completely a dog and completely a lizard. But that’s impossible, because each of these excludes the other.