Even the learned and dignified authorities on international law could not entirely ignore the methods employed in actual diplomatic intercourse. Grotius held that “amphibologies”--a term apparently coined by him to designate statements, which could be understood in several ways--were admissible, except in certain cases where there existed a duty to unmask, as in matters involving the “honor of God,” or charity towards a neighbor, or the making of contracts, or others of like nature. His successor, Vattel, draws a distinction between a downright lie, “words of him who speaks contrary to his thoughts on an occasion when he is under obligation to speak the truth”; and a “falsiloquy,” which he considers venial, and which is “an untrue discourse to persons who have no right to insist on knowing the truth in a particular case.” This distinction gives a rather ample latitude to the discretion of a diplomat in the matter of truthfulness. According to the good and learned Vattel, the duty of any one to tell the truth was binding only towards another who had the right to demand that the truth be spoken. In his day, very few people indeed could claim the right of demanding an insight into diplomatic affairs, so that his rule did not put the diplomat under a very severe moral constraint. Even to the present day there have been known individual envoys whose utterances plainly are made in the spirit of Vattel’s distinction. Callières, who wrote on the Practice of Diplomacy, in the year 1716, is full of admiration of all that a shrewd, clever diplomat may accomplish in stirring up trouble and confounding things generally in the state to which he is accredited. To the question, “What can be achieved by a negotiator?” Callières answers, “We see daily around us its definite effects--sudden revolutions favorable to a great design of state, use of sedition and fermenting hatreds, causing jealous rivals to arm, so that the third party may rejoice (_ut tertius gaudeat_), dissolution by crafty means of the closest unions. A single word or act may do more than the invasion of whole armies, because the crafty negotiator will know how to set in motion various forces native to the country in which he is negotiating and thus may spare his master the vast expense of a campaign.... It frequently happens that well chosen spies contribute more than any other agency to the success of great plans. They are not to be neglected. An ambassador is an honorable spy because it is his function to discover great secrets. He should have a liberal hand.” That admiration of successful deceit and mental cleverness in obtaining results that could only be gained by force through great sacrifice of life, inspired also the Italian admiration for clever deceit, such as shown by Machiavelli in his eulogy of Pope Alexander VI for his unrivaled eminence in prevarication.