Poor Daniel Gilbert: (Author of the beautiful book <i>Stumbling On Happiness</i>)<p>[ Priests vow to remain celibate, physicians vow to do no harm, and letter carriers vow to swiftly complete their appointed rounds despite snow, sleet, and split infinitives. Few people realize that psychologists also take a vow, promising that at some point in their professional lives they will publish a book, a chapter, or at least an article that contains this sentence: "The human being is the only animal that..." We are allowed to finish the sentence any way we like, but it has to start with those eight words. Most of us wait until relatively late in our careers to fulfill this solemn obligation because we know that successive generations of psychologists will ignore all the other words that we managed to pack into a lifetime of well-intentioned scholarship and remember us mainly for how we finished "The Sentence." We also know that the worse we do, the better we will be remembered. For instance, those psychologists who finished The Sentence with "can use language" were particularly well remembered when chimpanzees were taught to communicate with hand signs. And when researchers discovered that chimps in the wild use sticks to extract tasty termites from their mounds (and to bash one another over the head now and then), the world suddenly remembered the full name and mailing address of every psychologist who had ever finished The Sentence with "uses tools." So it is for good reason that most psychologists put off completing The Sentence for as long as they can, hoping that if they wait long enough, they just might die in time to avoid being publicly humiliated by a monkey.<p> <p>I have never before written The Sentence, but I'd like to do so now, with you as my witness. "The human being is the only animal that thinks about the future." ]