Each day at my blog, Café Hayek, I feature a quotation of the day (and sometimes a bonus quotation of the day). I share these quotations—which I select only from materials that I’ve actually read in full—because wisdom great in volume often comes packaged in words few in number. Choice quotations are a low-cost yet effective means of spreading wisdom.

But I recently got some grief after quoting from Oliver Wendell Holmes Jr.’s dissent in the 1919 Supreme Court case Abrams v. United States. In this case, the court ruled on the constitutionality of wartime legislation that criminalized certain expressions of opposition to the production of war materials. Only two members of the court—Holmes and Louis Brandeis—dissented from the majority, who found that this legislation did not violate the Constitution’s First Amendment.

In his dissent, Holmes famously advocated “free trade in ideas” because “the best test of truth is the power of the thought to get itself accepted in the competition of the market.” Holmes’ defense of freedom of speech is eloquent, creative, principled, and powerful. Considering that it was offered during a time when the patriotism stirred up by World War I was still swirling, Holmes’s defense was also courageous.

Importantly, Holmes’s defense of freedom of speech is one from which few, if any, classical liberals and libertarians dissent.

Holmes’s Heinous Assertion

So why did I get grief? The answer is that Holmes also led the 8-1 court majority in the 1927 case Buck v. Bell to uphold the constitutionality of a 1924 Virginia statute that authorized state officials to forcibly sterilize “mental defectives.” In his opinion for the majority, Holmes infamously wrote:

We have seen more than once that the public welfare may call upon the best citizens for their lives. It would be strange if it could not call upon those who already sap the strength of the State for these lesser sacrifices, often not felt to be such by those concerned, in order to prevent our being swamped with incompetence. It is better for all the world if, instead of waiting to execute degenerate offspring for crime or to let them starve for their imbecility, society can prevent those who are manifestly unfit from continuing their kind. The principle that sustains compulsory vaccination is broad enough to cover cutting the Fallopian tubes…. Three generations of imbeciles are enough.

Without question or qualification, every true classical liberal and libertarian, including myself, regards the Virginia statute, the court’s decision, and Holmes’ majority opinion as monstrous. It matters not that eugenics was all the rage among intellectual elites of that era. There is no place, ever, in a free society for forced sterilization, and any and all attempts to justify or to excuse it deserve nothing but unalloyed and vigorous condemnation.

But does Holmes’ heinous opinion in Buck v. Bell render his earlier ringing defense of freedom of speech unworthy of today being quoted favorably? I think not, although I confess that I understand the sentiment that leads some people to disagree with me.

Where to Draw the Line?

A person’s character, as expressed in words and actions over a lifetime, says much about the worthiness and credibility of that person’s words to impart wisdom and to inspire goodness in others. A deeply loathsome individual, even if he or she utters a sentiment that in isolation is agreeable and wise, ought never be quoted favorably. To pick an extreme example: It’s quite possible that Hitler somewhere wrote, or once said, a few sentences that, considered by themselves, appear to be not only sensible but inspiring. Yet anyone who would favorably quote such sentences from Hitler would commit an inexcusable offense against human decency.

The question is this: Where should we draw the line separating people who are so evil that even their wisest words should never be quoted favorably, from the rest of us, who, being neither devils nor angels, are suitable to quote favorably whenever any of us is inspired by some muse to string together admirable words of wisdom?

Most human beings throughout history have held, and many have acted upon, values and opinions that we today rightly regard to be unforgivable. But many of these men and women are also ones whose expressed ideas help to form the foundation of today’s liberal civilization.

I offer no formula or recipe for such line drawing. I am in possession of no such thing, and I doubt that anyone else is. What are here required, as they are so often, are wisdom and sound judgment. Yet I do wish to protest dogmatic rigidity. Most human beings throughout history have held, and many have acted upon, values and opinions that we today rightly regard to be unforgivable. But many of these men and women are also ones whose expressed ideas help to form the foundation of today’s liberal civilization.

Aristotle defended slavery. George Washington, Thomas Jefferson, and James Madison actually kept chattel slaves. If Oliver Wendell Holmes’ eloquent defense of free speech is unsuitable to quote because he, in another court case, held to be constitutional a statute that called for forced sterilization, why is it suitable to quote any of Jefferson’s many soaring defenses of individual liberty? Why do we not castigate those who favorably quote Madison’s contributions to The Federalist Papers? As bad an offense as it indisputably is to defend the constitutionality of statutes that call for forced sterilization, surely the actual enslavement of fellow human beings is an even worse offense.

I believe that Aristotle’s and Washington’s, Jefferson’s, and Madison’s complicity in supporting slavery renders none of these men unsuitable sources today of knowledge, wisdom, or inspiration. One reason for my belief is practical: If we were to take knowledge, wisdom, and inspiration only from saints, we would dramatically reduce our access to the colossal supply of knowledge, wisdom, and inspiration offered to us by history. And rejecting in the name of purity nearly all of this knowledge, wisdom, and inspiration, our society would quickly become polluted by ignorance and evil that would otherwise have been kept at bay.

Ad Hominem Is Indeed a Fallacy

A second reason for my belief is my understanding that the ad hominem fallacy is indeed a fallacy. While I realize that our knowledge limitations often justify our drawing some presumptions about the merits of arguments from the identities of those who deliver them, arguments should ultimately be judged by their contents rather than by the identities of their flesh and blood deliverers.

So while I understand the negative reaction to any favorable quotation from Holmes, I do not judge that particular imperfect man to have been so odious that we should refuse to hear whatever words he wrote in defense of freedom. Maybe in looking for inspiration, we should also stop looking for saints to canonize and witches to burn. We should instead seek insight wherever we can find it.

And on this matter you may quote me.

Donald J. Boudreaux is a senior fellow with the F.A. Hayek Program for Advanced Study in Philosophy, Politics, and Economics at the Mercatus Center at George Mason University, a Mercatus Center Board Member, and a professor of economics and former economics-department chair at George Mason University.

This article was reprinted with permission from the American Enterprise Institute on FEE.org. Read the original article at FEE.