The same human being can return an instructive book, available to him only once, in order not to miss the hunt; he can leave in the middle of a beautiful speech in order not to be late for a meal; he can abandon an entertainment marked by rational conversations, which he otherwise greatly esteems, in order to sit down at the gambling table; he can even turn away a pauper to whom ordinari he is glad to be charitable, because he happens to have no more money in his pocket than he needs in order to pay for admission to the theater.