Here are some quotes I've collected from previous thinkers, mostly well-known, both ancient and more modern--including Hegel, Bastiat, Spenser, Madison, Locke, as well as Knight, Madison, Machan, Rasmussen-den Uyl, Hare, Narveson. The quotes contain language evocative of the intuitions underlying Hoppe's argumentation ethics estoppel , or similar defenses of libertarian principles. (Many of the quotes below are drawn from my own publications , especially the footnotes in: A Libertarian Theory of Punishment and Rights and New Rationalist Directions in Libertarian Rights Theory, plus some other sources. I previously let John Cobin post some of them at his site .) If anyone has any suggestions for quotes to consider adding to this collection, send them on to me at nskinsella@gmail.com, or add to the comments, especially quotes that highlight some of the insights crucial to the argumentation or estoppel based defense of rights: e.g., the idea that when people come together to discuss ethical situations, they cannot deny ethical norms presupposed in argument itself; the idea that it's legitimate to use force against criminals simply because the logic of their own action is to endorse the use of force; etc."The only proof that can be offered for the validity of the liberal position is that we are discussing it and its acceptance is a presupposition of discussion, since discussion is the essence of the position itself." --Frank H. Knight, Freedom and Reform (Indianapolis: Liberty Press, 1982): 473=9674. "[T]he various values defended by liberalism are not arbitrary, a matter of mere personal preference, nor do they derive from some natural law . . . . Rather, they are nothing less and nothing more than what could be called the operative presuppositions or intrinsic features and demands of communicative rationality itself. In other words, they are values that are implicitly recognized and affirmed by everyone by the very fact of their engaging in communicative reason. This amounts to saying that no one can rationally deny them without at the same time denying reason, without self-contradiction, without in fact abandoning all attempts to persuade the other and to reach agreement. . . . [T]he notion of universal human rights and liberties is not an . . . arbitrary value, a matter of mere personal preference . . . . On the contrary, it is nothing less and nothing more than the operative presupposition or intrinsic feature and demand of communicative rationality itself." --G.B. Madison, The Logic of Liberty (New York: Greenwood Press, 1986): 266, 269. "[O]ur existence is due to the fact that we do not, indeed cannot accept a norm outlawing property in other scarce resources next to and in addition to that of one's physical body. Hence, the right to acquire such goods must be assumed to exist." --Hans-Hermann Hoppe, The Economics and Ethics of Private Property: Studies in Political Economy and Philosophy (Kluwer: 1993): 185. "[J]ust as one cannot win a game of chess against an opponent who will not make any moves--and just as one cannot argue mathematically with a person who will not commit himself to any mathematical statements--so moral argument is impossible with a man who will make no moral judgements at all . . . . Such a person is not entering the arena of moral dispute, and therefore it is impossible to contest with him. He is compelled also--and this is important--to abjure the protection of morality for his own interests." --R.M. Hare, Freedom and Reason (1963): A7 6.6TO argue with a man who has renounced the use and authority of reason, and whose philosophy consists in holding humanity in contempt, is like administering medicine to the dead, or endeavoring to convert an atheist by scripture." -- Thomas Paine The Crisis No. V "A man who would consider himself a bandit if, pistol in hand, he prevented me from carrying out a transaction that was in conformity with my interests has no scruples in working and voting for a law that replaces his private force with the public force and subjects me, at my own expense, to the same unjust restrictions." BASTIAT, FREDERIC, Harmonies "When men hire themselves out to shoot other men to order, asking nothing about the justice of their cause, I don't care if they are shot themselves." --Herbert Spencer, from Facts and Comments (1902) "[T]he victim is entitled to respond according to the rule ('The use of force is permissible') that the aggressor himself has implicitly laid down." --John Hospers, "Retribution: The Ethics of Punishment," in Assessing the Criminal: Restitution, Retribution, and the Legal Process, Randy E. Barnett and John Hagel III, eds., (Cambridge: Ballinger, 1977): p. 191. "The injury [the penalty] which falls on the criminal is not merely implicitly just--as just, it is eo ipso his implicit will, an embodiment of his freedom, his right; on the contrary, it is also a right established within the criminal himself, i.e., in his objectively embodied will, in his action. The reason for this is that his action is the action of a rational being and this implies that it is something universal and that by doing it the criminal has laid down a law which he has explicitly recognized in his action and under which in consequence he should be brought as under his right." --G.W.F. Hegel, The Philosophy of Right A7 100 (T.M. Knox trans., 1969) (reprinted in Philosophical Perspectives on Punishment (Gertrude Ezorsky ed., 1972): 107 (Emphasis in last sentence added; brackets in Ezorsky) "It is easier to commit murder than to justify it." --Papinian (Aemilius Papinianus), quoted in Barry Nicholas, An Introduction to Roman Law, p. 30 n.2 (1962). Alternative quote to the above: "Papinian [a third-century Roman jurist, considered by many to be the greatest of Roman jurists] is said to have been put to death for refusing to compose a justification of Caracalla's murder of his brother and co-Emperor, Geta, declaring, so the story goes, that it is easier to commit murder than to justify it." --Barry Nicholas, An Introduction to Roman Law, p. 30 n.2 (1962). Old saying: "What you do speaks so loud I can't hear what you are saying." --Quoted in Clarence Carson, "Free Enterprise: The Key to Prosperity", in The Freedom Philosophy Vol. 27, 27 (1988). "With him [an aggressor] we are returned to the first-stage state of nature and may use force against him. In so doing we do not violate his rights or in any other way violate the principle of right, because he has broken the reciprocity required for us to view such a principle [of rights] as binding. In this we find the philosophic grounding for the moral legitimacy of the practice of punishment. Punishment is just that practice which raises the price of violation of the principle of right so as to give us all good reason to accept that principle." --J. Charles King, A Rationale for Punishment, 4 J. Libertarian Stud. (1980): 154. "In transgressing the law of Nature, the offender declares himself to live by another rule than that of reason and common equity . . . and so he becomes dangerous to mankind; . . . every man . . . by the right he hath to preserve mankind in general, may restrain, or where it is necessary, destroy things noxious to them, and so may bring such evil on any one who hath transgressed that law, as may make him repent of the doing of it . . . ." B6 11: A murderer "hath, by the unjust violence and slaughter he hath committed upon one, declared war against all mankind, and therefore may be destroyed as a lion or a tiger, one of those wild savage beasts with whom men can have no society nor security." --John Locke, The Second Treatise on Civil Government B6 8 "It has been noted that one who wishes to extinguish or convey an inalienable right may do so by committing the appropriate wrongful act and thereby forfeiting it." --Randy E. Barnett, " Contract Remedies and Inalienable Rights ," Social Philosophy and Policy 4 (Autumn 1986): 186, citing Diana T. Meyers, Inalienable Rights: A Defense (New York: Columbia University Press, 1985), p. 14. "[W]hen someone is punished for having violated others' rights, it is not the case that the criminal has alienated or otherwise lost his rights; rather, it is the case that the criminal's choice to live in a rights-violating way is being respected." --Douglas B. Rasmussen & Douglas J. Den Uyl, Liberty and Nature: An Aristotelian Defense of Liberal Order (1991): 85 "[I]f someone attacks another, that act carries with it, as a matter of the logic of aggression, the implication that from a rational moral standpoint the victim may, and often should retaliate." --Tibor R. Machan, Individuals and Their Rights (1989): 176 "[T]hose who do not want peace, or want it only for others in relation to themselves rather than vice versa, are on their own and may in principle be dealt with by any degree of violence we like." --Jan Narveson, The Libertarian Idea (1988): 210 "What we cannot speak about we must pass over in silence." --Ludwig Wittgenstein, Tractatus Logico-Philosophicus, (D.F. Pears & B.F. McGuinness trans., London & New York: Routledge, 1961): Â¶ 7.0 (p. 74). "[L]ife for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, stroke for stroke." --Exodus 21:23-25, in God, The Jerusalem Bible: Reader's Edition (1968). See also Deuteronomy 19:21; Leviticus 24:17-21."[T]he basic axiom of libertarian political theory holds that every man is a self-owner, having absolute jurisdiction over his own body. In effect, this means that no one else may justly invade, or aggress against, another's person. It follows then that each person justly owns whatever previously unowned resources he appropriates or 'mixes his labor with'. From these twin axioms-- self-ownership and 'homesteading'--stem the justification for the entire system of property rights titles in a free market society." --Murray N. Rothbard, "Law, Property Rights, and Air Pollution," Cato Journal, Vol. 2 (1982): 60-61. "Whatever may be open to disagreement, there is one act of evil that may not, the act that no man may commit against others and no man may sanction or forgive. So long as men desire to live together, no man may initiate--do you hear me? No man may start--the use of physical force against others." --Ayn Rand, "Galt's Speech," in For the New Intellectual 164 (p. 133, paperback edition) (1961), quoted in The Ayn Rand Lexicon: Objectivism from A to Z (Harry Binswanger, ed. 1986), at 363."When we say that one has the right to do certain things we mean this and only this, that it would be immoral for another, alone or in combination, to stop him from doing this by the use of physical force or the threat thereof. We do not mean that any use a man makes of his property within the limits set forth is necessarily a moral use." --James A. Sadowsky, "Private Property and Collective Ownership," in The Libertarian Alternative, ed. Tibor R. Machan (Chicago: Nelson-Hall Co., 1974), 120=9621. "Having once the right to punish, we may modify the punishment according to the useful and the pleasant." --F.H. Bradley, Ethical Studies (2d ed. 1927): 26-27. "[W]e must distinguish two questions commonly confused. They are, first Why do men in fact punish? This is a question of fact to which there may be many different answers . . . . The second question, to be carefully distinguished from the first, is What justifies men in punishing? Why is it morally good or morally permissible for them to punish?" --H.L.A. Hart, Punishment and Responsibility (1968): 74. "[T]here is no affront [or injustice] where the victim consents." --[Roman jurist] Ulpian (Domitius Ulpianus), Edict, book 56, 4 The Digest of Justinian (Theodor Mommsen, Paul Krueger & Alan Watson eds., 1985), at Book 47, A7 10.1.5 (nulla iniuria est, quae in volentem fiat). "The case for the recognition of consent as a defense in case of the deliberate infliction of harm can also be made in simple and direct terms. The self-infliction of harm generates no cause of action, no matter why inflicted. There is no reason, then, why a person who may inflict harm upon himself should not, prima facie, be allowed to have someone else do it for him." --Richard A. Epstein, Intentional Harms, J. Legal Stud. 4 (1975): 411. "When men are judges in their own cases, it can be objected that "self-love will make men partial to themselves and their friends; and, on the other side, ill-nature, passion, and revenge will carry them too far in punishing others . . . ." --John Locke, The Second Treatise on Civil Government at 13 (B6 11) "But when mankind increased in number, craft, and ambition, it became necessary to entertain conceptions of more permanent dominion; and to appropriate to individuals not the immediate use only, but the very substance of the thing to be used. Otherwise innumerable tumults must have arisen, and the good order of the world been continually broken and disturbed, while a variety of persons were striving to get the first occupation of the same thing, or disputing which of them had actually gained it. As human life also grew more and more refined, abundance of conveniences were devised to render it more easy, commodious, and agreeable; as, habitations for shelter and safety, and raiment for warmth and decency. But no man would be at the trouble to provide either, so long as he had only an usufructuary property in them, which was to cease the instant that he quitted possession; if, as soon as he walked out of his tent, or pulled off his garment, the next stranger who came by would have aright to inhabit the one, and to wear the other." --2 William Blackstone, Commentaries on the Laws of England (last emphasis added): *4.