Freedom of speech lies at the heart of classical liberal thought. Without it, classical liberals have always understood, most other freedoms are nearly unprotectable and scarcely meaningful. Yet today, in America as in many ostensibly liberal nations, the freedom to speak one’s mind is under assault. Buttressing the intellectual defenses of freedom of speech against such attacks is the purpose of Jonathan Rauch’s Kindly Inquisitors: The New Attacks on Free Thought. Rauch’s achievement is no small accomplishment.
Eschewing, for the most part, traditional defenses of free thought, Rauch takes a broader view, drawing on the works of Thomas Kuhn, Karl Popper, and David Hume. To the well-understood liberal systems of politics and economics—representative government and free market economies—Rauch wishes to add the recognition of a liberal intellectual system, what he calls “liberal science.” On this system rests the very possibility of scientific knowledge, broadly understood. “Liberalism holds that knowledge comes only from a public process of critical exchange, in which wise and unwise alike participate.”
In the system of liberal science, it is through the exchange of ideas—and the resulting conflict between contrary viewpoints—that beliefs and observations are transformed into knowledge. As a result, the realm of knowledge is inherently restrictive; some things are true, others not. The only way to make that determination is by setting forth propositions and subjecting them to challenges. Reasonable hypotheses are entertained until they can be disproved. This removes from liberal science an element of certainty—all hypotheses are subject to challenge and revision but it is this process upon which the whole of knowledge depends. Without freedom of speech, thought, and inquiry (freedoms not wholly separable) liberal science cannot exist; without liberal science, truth cannot be separated from fiction.
Liberal science, by its very nature, has little tolerance for fundamentalism; conversely fundamentalism is a threat to liberal science. Fundamentalism, defined by Rauch as the “search for certainty rather than for errors,” is the antithesis of scientific inquiry. Fundamentalism seeks a monopoly on knowledge from which it can deny the beliefs put forth by all others. Rauch even notes that there are fundamentalist free-marketeers—those who refuse to accept the possibility that cherished economic axioms may be flawed, or at least in need of revision—and he challenges them to enhance their intellectual rigor. If classical liberals are willing to accept the self-correcting actions of the marketplace to properly allocate valued resources, they should also allow the self-correcting mechanisms of liberal science to separate knowledge from supposition.
Due to its nature as a decentralized system, liberal science frees knowledge from authoritarian control by self-appointed commissars of truth. “In an imperfect world, the best insurance we have against truth’s being politicized is to put no one in particular in charge of it,” notes Rauch. Liberal science achieves this end. It avoids despotism in the intellectual realm as it does in those of politics and economics.
Just as capitalism makes some rich and others poor, liberal science accepts the beliefs of some as knowledge, while rejecting those of others; the game of liberal science creates winners and losers. This, without fail, generates opposition. And so one sees the erection of rules against certain forms of expression. These rules bar “hate speech” in Canada, “historical revisionism” in France, and “insults” directed at minorities in Great Britain.
This siege of liberal science has even reached American shores. “In America,” notes Rauch, “the movement against hurtful speech has been primarily moral rather than legal, and nongovernmental institutions, especially colleges and universities have taken the lead.” The threat is not that private institutions establish rules to enforce civility within their own confines but the principle on which such rules are being established. Rauch warns, “A very dangerous principle is now being established as a social right: Thou shalt not hurt others with words.” This principle threatens the whole of liberal science.
The search for truth entails the examination of all ideas. This makes it inevitable that some will be hurt. In the process of identifying mistaken beliefs, liberal science necessarily wounds those who hold them. “Liberal science does not restrict belief,” argues Rauch, “but it does restrict knowledge” [emphasis in original]. It allows each individual to think for himself, but it requires that beliefs be tested and challenged before they can be accepted as true. Thus, to limit criticism in the name of protecting individuals, ethnicities, or creeds from harm is to limit the ability of liberal science to search for truth by ferreting out falsehoods. Rauch notes that “A no-offense society is a no-knowledge society,” and a “no-knowledge” society is good for no one.
The determination of knowledge through liberal science works well in the realm of fact and fiction. But by Rauch’s own admission it is more limited in its ability to discern good from evil; “It is true that the science rules cannot resolve moral questions in the way they can often lead to quick resolutions of questions of fact. You can’t perform a study or run an experiment to determine whether abortion is murder or capital punishment is cruel. However, let it be said in favor of the science rules that they can help bring order and peacefulness to moral debate.” By establishing criteria for the examination of ideas, liberal science allows for the peaceful exchange of hostile ideas. Thus “liberal science can help people organize the search for decent moral principles” even though “it is incomplete as to providing them.”
Kindly Inquisitors is a slim volume that deserves to be well read and widely discussed. Over time, one can hope that Rauch’s beliefs will be accepted, scientifically, as knowledge. 
Jonathan H. Adler is a policy analyst at the Competitive Enterprise Institute in Washington, D.C.