IT IS almost impossible to look into the eyes of a dog without wondering what it is thinking. And if you take it for a walk, there will be more to wonder at: what the bizarre things it sniffs actually smell like, or how the dog hears or sees the world.
But perhaps you can never know. Our sense of being shut out of the animal’s mind was brilliantly expressed by the philosopher Thomas Nagel, in his famous 1974 essay “What is it like to be a bat?” Nagel was a pessimist; he believed that a kind of cognitive curtain…
