What is a person? “A wingless, two-legged creature with flat nails, receptive to knowledge based on reasoning,” Plato claimed. And—adds psychology professor at Yale University Paul Bloom—people are hooked on pleasure. The scientist explains the appeal of things and phenomena—ranging from food to idleness, from religion to shopping, from art to pornography—sometimes even in paradoxical ways, and reflects on whether it’s worth arguing about tastes.