Real estate license exams are reminiscent of Felix Cohen's attack more than fifty years ago upon the magic solving words of traditional jurisprudence, which he charged add precisely as much to our knowledge as Moliere's physician's discovery that opium puts men to sleep because it contains a dormitive principle. "Title" and "property rights" were among the "magic "solving words Cohen cited, as were "corporate entity," "fair value," and "due process." Nine years later, the Restatement of Property acknowledged that an "interest" in property "cannot exist without the existence of facts which the law recognizes as resulting in the interest," but declined to use that term to denote the operative facts themselves. Men buy or sell interests in land, chattels, and other things, not operative facts.