Some can’t imagine a downside to punching Nazis, or otherwise obstructing their spewing of hate. How could the world not be a happier and sunnier place after the forcible removal of such a spiritual pollutant? In the face of such an obvious potential pragmatic benefit to society, isn’t concern for the rights of Nazis so much fussy, abstract philosophizing?
David Hume shed some light on this problem, explaining way back in 1738 the pragmatic utility and public interest in granting even “a seditious bigot” his rights.
The Case of the Robbed Nazi
In his Treatise on Human Nature, Hume wrote:
A single act of justice is frequently contrary to public interest; and were it to stand alone, without being followed by other acts, may, in itself, be very prejudicial to society. When a man of merit, of a beneficent disposition, restores a great fortune to a miser, or a seditious bigot, he has acted justly and laudably; but the public is the real sufferer.
Many would consider “seditious bigot” a perfectly apt term for the Nazis and white supremacists now seizing public attention. Let’s say, following Hume’s hypothetical, a Nazi, who had grown rich through honest business, had been robbed of a “great fortune”: let’s say a collection of antique German coins. Then, a person “of a beneficent disposition” who believes in the human rights of all (in other words, someone who is quite the opposite of a Nazi) somehow came into possession of the pilfered coins and returned the fortune to the seditious Nazi bigot.
This, according to a strict application of property rights, would, as Hume put it, be a “single act of justice.” The Nazi’s fortune was his property by right, so restoring that property was indeed a single act of justice.
But what will the Nazi do with his restored fortune? What if he uses it to finance web sites and Twitter bots broadcasting hate throughout the Internet? Clearly, in that case, “the public is the real sufferer” as Hume put it.
The human rights champion who returned the fortune might even personally suffer. Maybe he individually, or a group in which he is a member, will be one of the targets of the Nazi’s campaign of hate. By striving to act with strict integrity, he may have hurt his own interests. As Hume wrote:
Nor is every single act of justice, considered apart, more conducive to private interest than to public; and it is easily conceived how a man may impoverish himself by a single instance of integrity, and have reason to wish that, with regard to that single act, the laws of justice were for a moment suspended in the universe.
Now, take the above thought experiment, but replace one matter of rights with another. Instead of the Nazi’s ownership right over external property, consider his right of self-ownership, which includes his right of free speech.
Let’s say that this right, too, is defended by a champion of universal rights, namely a libertarian: someone whose credo is the furthest conceivable thing from that of a Nazi.
Again, such a defense may seem contrary to the public good, since the Nazi’s message accomplishes nothing but evil. It may even seem contrary to the libertarian’s personal interests since collectivist, particularist Nazis often rightly recognize individualist, universalist libertarians as their antithesis and as their most dangerous ideological nemeses.
The Pragmatism of Principle
But such regrettable results are not the only consequences of affording the Nazi his rights. We must consider Frederic Bastiat’s “unseen” as well the “seen”: namely the wider ramifications of maintaining a universal principle: a general rule. As Hume continued (emphasis added):
But however single acts of justice may be contrary either to public or private interest, it is certain that the whole plan or scheme is highly conductive, or indeed absolutely requisite, both to the support of society, and the well-being of every individual. It is impossible to separate the good from the ill. Property must be stable, and must be fixed by general rules. Though in one instance the public be a sufferer, this momentary ill is amply compensated by the steady prosecution of the rule, and by the peace and order which it establishes in society. And even every individual person must find himself a gainer on balancing the account; since, without justice, society must immediately dissolve, and every one must fall into that savage and solitary condition which is infinitely worse than the worst situation that can possibly be supposed in society.
Once you start making exceptions to a universal principle/general rule, you begin to undermine it; it becomes easier to make further exceptions. If the hate speech of Nazis are to be restricted, why not the hate speech of traditionalist conservatives? If the violent, seditious rhetoric of Nazis are too dangerous to allow, why should the violent, seditious rhetoric of communists be tolerated, or any fundamental criticism of the government?
As Jeffrey Tucker recently wrote:
Once you pick and choose the way you want rights exercised, you threaten the very idea of rights and make them all contingent on political expediency.
And Ludwig von Mises, in Human Action, granted that, in the single case of ads for quack remedies, it might do no public harm…
…if the authorities were to prevent such advertising, the truth of which cannot be evidenced by the methods of the experimental natural sciences. But whoever is ready to grant to the government this power would be inconsistent if he objected to the demand to submit the statements of churches and sects to the same examination. Freedom is indivisible. As soon as one starts to restrict it, one enters upon a decline on which it is difficult to stop. If one assigns to the government the task of making truth prevail in the advertising of perfumes and tooth paste, one cannot contest it the right to look after truth in the more important matters of religion, philosophy, and social ideology.
As Hume said, the more you erode the universality of rights, the more society devolves toward the “anything goes” law of the jungle. And it is precisely Nazi-like brutes who thrive under such conditions, at the expense of the civility-minded.
It's about More than the Nazis
When libertarians and other sincere defenders of the freedom of speech, like a great many in the ACLU, defend the free speech rights of Nazis, their greatest concern is not the defense of Nazis as such, but the defense of a vitally important principle and general rule.
Such a defense is especially vital in a world in which it is quite possible for the reins of government to be seized by violent bigots themselves. This idea has been vividly expressed in the 1960 film Man for All Seasons, in an exchange between Sir Thomas More and another character:
Roper: So now you’d give the Devil benefit of law!
More: Yes. What would you do? Cut a great road through the law to get after the Devil?
Roper: I’d cut down every law in England to do that!
More: Oh? And when the last law was down, and the Devil turned round on you — where would you hide, Roper, the laws all being flat? This country’s planted thick with laws from coast to coast — man’s laws, not God’s — and if you cut them down — and you’re just the man to do it — d’you really think you could stand upright in the winds that would blow then? Yes, I’d give the Devil benefit of law, for my own safety’s sake.
Now read the above again with “Nazi” substituted for “Devil.”
This is the pragmatic rationale behind taking the stance of the early champion of free speech and tolerance Voltaire, which was encapsulated by Evelyn Beatrice Hall as follows:
I disapprove of what you say, but I will defend to the death your right to say it.
 Hume traces the rise of property and justice themselves to this individual recognition of the personal benefit of rigorously applied general rules:
When, therefore, men have had experience enough to observe that whatever may be the consequence of any single act of justice, performed by a single person, yet the whole system of actions concurred in by the whole society is infinitely advantageous to the whole, and to every part, it is not long before justice and property take place. Every member of society is sensible of this interest: every one expresses this sense to his fellows, along with the resolution he has taken of squaring his actions by it, on condition that others will do the same. No more is requisite to induce any one of them to perform an act of justice, who has the first opportunity. This becomes an example to others; and thus justice establishes itself by a kind of convention or agreement, that is, by a sense of interest, supposed to be common to all, and where every single act is performed in expectation that others are to perform the like. Without such a convention, no one would ever have dreamed that there was such a virtue as justice, or have been induced to conform his actions to it. Taking any single act, my justice may be pernicious in every respect; and it is only upon the supposition that others are to imitate my example, that I can be induced to embrace that virtue; since nothing but this combination can render justice advantageous, or afford me any motives to conform myself to its rules.
 Henry Hazlitt, in his book The Foundation of Morality, characterized Hume as the originator of the ethical tradition of “rule utilitarianism” as distinct from the “act utilitarianism” often associated with Jeremy Bentham.