The following is taken from Thomas Hobbes’ Leviathan, ed. Edwin Curley (Hackett, 1994 [orig. 1651]), ch. xv, ¶ 5, pp. 91-92; the first two bracketed insertions are mine, the third that of the editor; the emphases are mine:
[I]n a condition of war, wherein every man to every man (for want of a common power to keep them all in awe) is an enemy, there is no man [who] can hope by his own strength or wit to defend himself from destruction without the help of confederates (where everyone expects the same defence by the confederation that anyone else does); and therefore, he which declares he thinks it reason to deceive those that help him can in reason expect no other means of safety than what can be had from his own single power. He, therefore, that breaketh his covenant, and consequently declareth that he thinks he may with reason do so, cannot be received into any society that unite themselves for peace and defence but by the error of them that receive him; nor when he is received, be retained in it without seeing the danger of their error; which errors a man cannot reasonably reckon upon as the means of his security; and therefore, if he be left or cast out of society, he perisheth; and if he live in society, it is by the errors of other men, which he could not foresee nor reckon upon; and consequently [he has acted] against the reason of his preservation, and so as all men that contribute not to his destruction forbear him only out of ignorance of what is good for themselves.
A corresponding passage can be found in a different version of Leviathan written by Hobbes in Latin that was later published in 1688 (although parts of it may have been written earlier than the English version):
[I]n the natural condition, where each one is an enemy to each one, no one can live securely without the aid of allies. But who, except by ignorance, will admit into society, which one enters by mutual covenants for the defense of the individual members, a man who thinks it rational to break covenants? Who, except by ignorance, will retain him if he has been admitted? So, either he will be cast out and perish, or he will owe his not being cast out to the ignorance of the others, which is contrary to right reason.
Ibid., p. 92, n. 7.
To put it even more plainly, Hobbes is saying that only a very foolish society would tolerate the presence of known liars in its midst. But unfortunately, that’s exactly what our own society does—which makes ours a very foolish society.
Of course, people in the modern world would never support literally “casting out” the dishonest members of society and leaving them to “perish” in the wilderness (partly because there are so many people who are dishonest). But I do suggest a “kinder and gentler” analogue of that course of action in my overview of “truth groups” and the “honesty culture” strategy, in which I propose that the unrepentantly dishonest members of society be increasingly “shunned,” or “boycotted,” or “ostracized” by the members of a gradually growing and increasingly powerful “honesty culture.”
So I do not advocate that “all men contribute to the destruction” of the dishonest members of society; but I do advocate that “all men contribute to the destruction” of the dishonesty of such persons. And I suggest that this could be accomplished if those members of society who already earnestly wish to be honest and to promote honesty in society incrementally withdrew themselves from the company of the unrepentantly dishonest members of society, so that the latter would be unable to enjoy the benefits of interacting with (and having opportunities to unfairly exploit the ingenuousness, trust, and good will of) the former. The “honesty culture” would never seek to directly destroy anyone; but, by its own members choosing, whenever reasonably possible, not to associate with outsiders, it would be demonstrating its willingness to step back and allow the stubbornly dishonest members of society to destroy each other, and themselves—if that’s what they were determined to do. Taking such a course of action would, in effect, amount to a constructive “banishment” or “ostracism,” even in spite of the fact that a literal banishment (such as was practiced by the city-states of ancient Greece) is not usually a practicable punishment in the modern world.
But unlike what it seems Hobbes may be suggesting in the passages of his that I quoted, the strategy I am proposing would always look forward to the receiving back and rehabilitating of those formerly “banished” members of society, once they had come to recognize the errors of their ways—that is (to use Hobbes’ language), once they had learned to act “reasonably,” “rationally,” and in accordance with “the reason of their preservation.” I fully expect that persons would decide to become members of the “honesty culture” long before any of them were in any danger of literally “perishing” (at least as a result of something like starvation—violent criminal homicide would be another matter altogether, since the occurrence of a particular incident of homicide is often very sudden and unexpected, and so doesn’t allow the victim any opportunity to regret and repent of those prior life decisions which may have been partly responsible for placing him in a dangerous situation in the first place). All persons would choose to join the “honesty culture” just as soon as they perceived that the disadvantages of remaining outside of the “honesty culture” exceeded the advantages; and the doors to the “honesty culture” would always remain wide open to all persons who sincerely wished to enter it—regardless of what they had done in the past.