In such places (he went on at last), where animals are simply penned up, they are almost always more thoughtful than their cousins in the wild. This is because even the dimmest of them cannot help but sense that something is very wrong with this style of living. When I say that they are more thoughtful, I don't mean to imply that they acquire powers of ratiocination. But the tiger you see madly pacing its cage is nevertheless preoccupied with something that a human would certainly recognize as a thought. And this thought is a question: Why? “Why, why, why, why, why, why?” the tiger asks itself hour after hour, day after day, year after year, as it treads its endless path behind the bars of its cage. It cannot analyze the question or elaborate on it. If you were somehow able to ask the creature, “Why what?” it would be unable to answer you. Nevertheless this question burns like an unquenchable flame in its mind, inflicting a searing pain that does not diminish until the creature lapses into a final lethargy that zookeepers recognize as an irreversible rejection of life. And of course this questioning is something that no tiger does in its normal habitat.
— Daniel Quinn, Ishmael, p.11