" What', said he, ' makes the difference between man and all the rest of the animal creation? Every beast that strays beside me has the same corporeal necessities with myself; he is hungry and crops the grass, he is thirsty and drinks the stream, his thirst and hunger are appeased, he is satisfied and sleeps; he rises again and is hungry, he is again fed and is at rest. I am hungry and thirsty like him, but when thirst and hunger cease I am not at rest; I am, like him, pained with want, but am not, like him, satisfied with fullness. The intermediate hours are tedious and gloomy; I long again to be hungry that I may again quicken my attention. The birds peck the berries or the corn, and fly away to the groves where they sit in seeming happiness on the branches, and waste their lives in tuning one unvaried series of sounds. I likewise can call the lutanist and the singer, but the sounds that pleased me yesterday weary me today, and will grow yet more wearisome tomorrow. I can discover within me no power of perception which is not glutted with its proper pleasure, yet I do not feel myself delighted. Man has surely some latent sense for which this place affords no gratification, or he has some desires distinct from sense which must be satisfied before he can be happy. "

― Samuel Johnson