Our sympathy with sorrow, though not more real, has been more taken notice of than our sympathy with joy.

—Adam Smith, Theory of Moral Sentiments

AS FAR AS WE currently know, it is only human beings who can imagine what it is like to be in someone else’s shoes. It is an ability with profound effects. It might have helped prehistoric hunters to be able to imagine what their prey would do. Complex human societies would be inconceivable without the ability to imagine what other people might do or wish or fear under particular circumstances. This is different from—and more sophisticated than—simply inferring how another might instinctively react. It is an ability so facile that we often don’t even notice it in ...

Get Us Plus Them now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.