(16:31) As a necessary consequence of the principle just enunciated, no one can honestly promise to forego the right which he has over all things [Endnote 26], and in general no one will abide by his promises, unless under the fear of a greater evil, or the hope of a greater good. (32) An example will make the matter clearer. (33) Suppose that a robber forces me to promise that I will give him my goods at his will and pleasure. (34) It is plain (inasmuch as my natural right is, as I have shown, co-extensive with my power) that if I can free myself from this robber by stratagem, by assenting to his demands, I have the natural right to do so, and to pretend to accept his conditions. (35) Or again, suppose I have genuinely promised someone that for the space of twenty days I will not taste food or any nourishment; and suppose I afterwards find that was foolish, and cannot be kept without very great injury to myself; as I am bound by natural law and right to choose the least of two evils, I have complete right to break my compact, and act as if my promise had never been uttered. (36) I say that I should have perfect natural right to do so, whether I was actuated by true and evident reason, or whether I was actuated by mere opinion in thinking I had promised rashly; whether my reasons were true or false, I should be in fear of a greater evil, which, by the ordinance of nature, I should strive to avoid by every means in my power. (16:37) We may, therefore, conclude that a compact is only made valid by its utility, without which it becomes null and void. (38) It is, therefore, foolish to ask a man to keep his faith with us for ever, unless we also endeavour that the violation of the compact we enter into shall involve for the violator more harm than good. (39) This consideration should have very great weight in forming a state. (40) However, if all men could be easily led by reason alone, and could recognize what is best and most useful for a state, there would be no one who would not forswear deceit, for everyone would keep most religiously to their compact in their desire for the chief good, namely, the shield and buckler of the commonwealth. (41) However, it is far from being the case that all men can always be easily led by reason alone; everyone is drawn away by his pleasure, while avarice, ambition, envy, hatred, and the like so engross the mind that, reason has no place therein. (42) Hence, though men make promises with all the appearances of good faith, and agree that they will keep to their engagement, no one can absolutely rely on another man's promise unless there is something behind it. (43) Everyone has by nature a right to act deceitfully, and to break his compacts, unless he be restrained by the hope of some greater good, or the fear of some greater evil.