"Two Theories of Toleration: Locke versus Mill" by Adam Wolfson, in Perspectives on Political Science (Fall 1996), 1319 18th St. N.W., Washington, D.C. 20036–1802.

Many Americans today worship at the shrine of tolerance. They hold fast to the "one very simple principle" that John Stuart Mill enunciated in On Liberty (1859): that society should never interfere with the liberty of the individual except to prevent harm to others. But, argues Wolfson, executive editor of the Public Interest, there are serious hazards in that libertarian outlook, as an earlier advocate of toleration, John Locke, well knew.

Mill’s expansive view of liberty rests, in most interpretations, on an interest in securing truth through open debate. But Wolfson asserts that "it is not liberty that secures truth... but rather, [Mill’s] peculiar, quite relativistic, notion of the truth that secures the widest possible liberty of thought and action." As depicted in On Liberty, Wolfson says, truth is so complex and many-sided that it cannot be grasped by most individuals except at the level of society, where the various contending halftruths and falsehoods are brought into a rough balance. Even the "truth" thus arrived at by society is really only, in Mill’s words, a "fragment of truth."

By the time Mill is done, Wolfson says, "there is little sense that [truth] is something available, much less desirable." Instead, fearful that intolerance might stamp out individuality, Mill calls for "different experiments of living," "varieties of character," and "free development of individuality." Certain that the commonwealth is secure and that moral truth cannot be infallibly established, Mill, like many Americans today, "permits, indeed encourages, the cultivation of opinions and behaviors that are at odds with liberalism."

Locke, in contrast, in A Letter Concerning Toleration (1689), largely confined toleration to the realm of speculative thought. "The Magistrate ought not to forbid the Preaching or Profession of any Speculative Opinions," he declared. But practical opinions, which "influence the Will and Manners," were another story. Unlike Mill, Locke believed that "Morality is capable of Demonstration, as well as Mathematicks," and that the state ought to discourage pernicious practical opinions.

In Locke’s view, Wolfson says, "a liberal society could not survive, much less prosper, without a preponderance of morality and rationality existing among the citizenry." And government, therefore, had "at least some interest" in shaping the character of its citizens. That is a lesson, Wolfson concludes, that modern libertarians, who often claim Locke as a founding father, seem to have forgotten.