The libertarian philosophy is embedded in Enlightenment liberalism. This is clearly seen in its commitment to free inquiry (reason) and free speech, the full realization of which, I argue, requires complete respect for individual rights, including property rights.

Unfortunately we live at a time when those values are increasingly under assault from from a variety intellectuals and activists despite political and cultural differences among themselves. We hear prominent people ask–and it’s really an assertion disguised as a question–whether free inquiry and free speech are really all they have been cracked up to be in light of the American condition. This seems to be a change even from the recent past, when question like that would likely come only from the most authoritarian fringes of the left and right.

Advocates of individual liberty and the rich patterns of cooperation that liberty generates have reason worry. Nothing good would be gained from restrictions on those Enlightenment values–regardless of whether the restrictions came from the government or private sources. Nothing good at all.

Whatever one’s fears about the state of American culture, it is difficult to see how stifling inquiry and speech could improve matters. Whether one is a left-collectivist who believes Enlightenment values lock in white male supremacy or a right-collectivist who believes those values have allowed the left to control the culture’s commanding heights, the crushing of true liberalism can only lead to disaster, eventually for everyone.

You need not be a libertarian to see the point, and fortunately we see nonlibertarians all around the political spectrum expressing dismay about the new disparagement of free-wheeling inquiry and uninhibited expression of its findings.

This is not rocket science. Squelching speech does not make alleged bad thoughts go away. On the contrary, it may give them an illusion of legitimacy they would never have achieved in open discussion. When a subject becomes taboo, even good-faith people may reasonably ask, “What are the self-appointed censors so scared of? Does the forbidden claim have merit that I’ve overlooked?” How does that help the censors beat back ideas?

The value of the open competitive marketplace of ideas is so obvious that it ought not require repeating. We learn through the contest among ideas. The way to defeat an assertion is not to suppress it, but to rebut it. No idea is so dangerous that it has to be banned from the marketplace. A free society cannot tolerate thought police, whether political or private.

To cherish the intellectual marketplace, one only need realize that even someone who is thoroughly wrong about a particular matter or event (and perhaps even ill-intentioned) could contribute to our knowledge by stumbling on an overlooked truth. We just never known who might be the one to set the record straight in some way. (The leftist Norman Finkelstein has admirably made this point many times.)

Moreover, it’s important that the intellectual marketplace–like the commercial marketplace and for the same reasons–not be rigged by the state in any way. All intellectual products should have to compete in a just (that is, rights-respecting) arena. Force is to be barred. But that’s all that needs barring. Now may the best ideas win.

This does not mean that the common-sense rules of respect needn’t be observed or that those who violate the rules should never be called to account. But it does mean that toleration is also a virtue when directed at offenders. We are rightly uncomfortable when people lose their livelihoods for saying the “wrong” thing in the “wrong” way. It is difficult to confine this kind of punishment to only the worst offenders. Boomerangs have a way of coming back at you.

Does an open marketplace guarantee that the truth always always wins right away? Of course not. But it’s the best chance we have of rooting out error in the shortest time. The market certainly beats any imaginable alternative, which would have to be one form or another of authoritarianism. No thank you.

It’s in the nature of ideas, as with all tools, that they can be used for good or ill. Stifling discussion because bad people may capitalize on fact can hardly be grounds for shutting down the intellectual marketplace. One could think of no surer example of the cure being worse than the alleged disease.

It’s time for all true liberals, whatever their differences, unite to defend free inquiry and free speech.