The economist Tyler Cowen, who recently told me he uses the app more than he does Google, wrote the best essay I’ve read so far on the subject. His argument is that—as with fire, and the printing press, and the car, and the internet—this technology cannot and will not be stopped. The question, in other words, isn’t one of yes or no. Instead it’s: How will we learn to harness it? What will we do with it? And what will it do to us?