““Let's put a chimpanzee in a tiny cage fronted by concrete bars. The animal would go berserk, throw itself against the walls, rip out its hair, inflict cruel bites on itself, and in 73% of cases will actually end up killing itself. Let's now make a breach in one of the walls, which we will place next to a bottomless precipice. Our friendly sample quadrumane will approach the edge, he'll look down, but remain at the edge for ages, return there time and again, but generally he won't teeter over the brink; and in all events his nervous state will be radically assuaged.””
