Freedom of thought is a generic label that includes freedom of religion, speech, press, and artistic creation. It also was affiliated with a tradition of religious skepticism known as “freethinking” and “freethought.” It is scarcely coincidental that 18th‐​century freethinkers were often associated with libertarian causes, such as freedom of speech and press. When dealing with an established church, such as the Anglican Church in England or the Catholic Church in France, to criticize the doctrines of Christianity also was to challenge the political status quo and render oneself vulnerable to potentially severe punishments for blasphemy.

The words freethinking and freethinker made their first appearance in English literature during the latter part of the 17th century, when they were applied to Pantheists, Epicureans, Pelagians, Socinians, Deists, and others who dissented from traditional Christian doctrines. Although freethinker began as a term of opprobrium because it described a person who preferred the judgments of his or her own reason over the dictates of a religious or secular authority, it was soon embraced by many proponents of intellectual independence.

The most influential defense of freethinking was written by Anthony Collins, a Radical Whig and literary executor of John Locke’s estate. In A Discourse of Free‐​Thinking (1713), Collins wrote:

By free‐​thinking I mean the use of the understanding in endeavoring to find out the meaning of any proposition whatsoever, in considering the nature of the evidence for or against it, and in judging of it according to the seeming force of the evidence.

As defined here, freethinking is synonymous with the critical investigation of a belief or doctrine. Collins was calling for more than the legal freedom to use one’s mind; he was also challenging the widespread belief that some beliefs, whether in religion or politics, are sacrosanct and should therefore be immune to critical inquiry. In other words, Collins was defending the moral right to freedom of thought. As he put it, “we have a right to know or may lawfully know any truth. And a right to know truth whatsoever implies a right to think freely.”

Arguments for freedom of thought were not confined to religious skeptics or to one particular religious group. The remarkable advances in science during the 17th century, which entailed the wholesale rejection of orthodox scholastic doctrines in physics and astronomy, illustrated the value of unrestrained critical inquiry. Equally important was the development of modern philosophy. René Descartes, for example, employed systematic doubt as a means of arriving at certainty. Although Descartes was careful to exempt essential moral and religious ideas from this methodical doubt, the Cartesian method—which was devoid of any appeals to authority—effectively communicated the message that freedom of thought is indispensable to the pursuit of truth.

The other great pioneer in modern philosophy in this period was Francis Bacon, a severe critic of orthodox doctrines in science and philosophy who called for a new “instauration” of knowledge. Perhaps the most lasting contribution of Bacon was his discussion of various “idols,” or prejudices, of the human mind that hindered the pursuit of objective knowledge. The upshot was a stress on human fallibility and the innocence of error. There are various reasons that even well‐​intentioned people may disagree, according to Bacon. Dissent was not necessarily a result of the deliberate rejection of truth. Knowledge is cumulative; it advances as new information is discovered by empirical means. Intellectual progress (or what Bacon called “the advancement of learning”) requires a continuous process of criticism, a willingness to examine accepted beliefs and of sorting the true from the false.

Arguments for freedom of thought appeared in various pleas for religious toleration and freedom of speech and press throughout the 17th century. One of the most influential was John Milton’s book, Areopagitica (1644), which was cited as late as 1851 by Herbert Spencer in his Social Statics as presenting a definitive case for toleration. Milton’s eloquent words—“Give me the liberty to know, to utter, and to argue freely according to my conscience, above all liberties”—would frequently be quoted by later libertarian writers.

Milton was a Puritan in his earlier years, but his fierce love of liberty caused him to repudiate the Puritan claim to a monopoly on religious truth. Thus, when the Puritan Parliament reinstated a law requiring the licensing of books in 1643, Milton responded with his Areopagitica, subtitled “A Speech for the Liberty of Unlicensed Printing, to the Parliament of England.”

Although the Areopagitica defense of religious toleration did not extend to “Popery and open superstition,” his forceful arguments transcended his own exceptions. Moreover, although his arguments specifically addressed prepublication licensing, they had much broader implications for freedom of thought. The inner logic of Milton’s arguments would later be developed by libertarians and Applied to areas other than freedom of the press.

Especially significant was Milton’s statement that “here the great art lies, to discern in what the law is to bid restraint and punishment, and in what things persuasion only is to work.” This attempt to draw a bright line between the proper spheres of state coercion and voluntary social interaction reflected a dominant theme in libertarian political theory.

Much of the Areopagitica is devoted to the idea that liberty is the best “school of virtue,” a theme Milton was to take up in another essay. Milton contended that virtue and vice flowed from the same source, namely, the inner dispositions of the individual and that dispositions are ultimately determined by the judgments of reason. Because reason is “but choosing” (i.e., because reason is the seat of man’s moral agency), an action can be deemed virtuous only insofar as it flows from a free, uncoerced choice. Hence, “They are not skillful considerers of human thing, who imagine to remove sin by removing the matter of sin.…” The “trial of virtue” requires a free society in which individuals are free to form their own judgments and learn from their mistakes. God does not “captivate [man] under a perpetual childhood of prescription, but trusts him with the gift of reason to be his own chooser.”

During the 17th century, as arguments for free trade became increasingly popular, we find a number of analogies between freedom of thought and commercial freedom. In Liberty of Conscience (1643), the English merchant Henry Robinson discussed “free trading of truth.” Similarly, Milton compared the licensing of books to a commercial monopoly enforced by law, which “hinders and retards the importation of our richest Merchandise, Truth.” By the early 19th century, British liberals explicitly defended freedom in religion (and of ideas generally) as one aspect of free trade. We commonly find expressions like “free trade in religion” and “free trade in Christianity” among foes of the Established Church.

This notion led to a theory of spontaneous order in ideas, one in which truth is most likely to emerge from uncoerced intellectual activity. According to Milton, truth “needs no policies, nor stratagems, nor licensing to make her victorious.” The philosopher Spinoza agreed that “freedom is absolutely necessary for progress in science and the liberal arts: for no man follows such pursuits to advantage unless his judgment be entirely free and unhampered.” John Locke was another who maintained that truth will fare well in the ideological marketplace: “Truth certainly would do well enough, if she were once made to shift for herself.…She is not taught by laws, nor has she any need of force to procure her entrance into the minds of men.”

Even after the arguments for freedom of thought and expression had become widely accepted in Europe and America, there was a concern among those philosophers and social theorists who were proponents of freedom of thought that the absence of legal restraints was not sufficient to maintain the intellectual vitality required for a free society. This concern was expressed by Alexis de Tocqueville in his classic work, Democracy in America. Tocqueville’s visit to America led him to arrive at a startling conclusion regarding its people: “I know of no country in which, generally speaking, there is less independence of mind and true freedom of discussion than in America.” The majority in America has “enclosed thought within a formidable fence. A writer is free inside that area, but woe to the man who goes beyond it.” Freedom of thought, which despotic monarchs had attempted in vain to suppress, was controlled in America by the power of public opinion. A dissenter with radical beliefs, although he may not have suffered legal punishment, could well find himself a social outcast, a person unable to hold political office and shunned by his neighbors.

A single despot, Tocqueville concluded, is able to strike the body, whereas a democracy “leaves the body alone and goes straight for the soul.” “Thought,” he wrote, “is an invisible power and one almost impossible to lay hands on, which makes sport of all tyranny.” Even the most absolute of European sovereigns with an unlimited power to punish the body cannot prevent the spread of seditious and unorthodox ideas within their realms or even within the confines of their own courts. But American democracy, in which the will of the majority is invested with a quasi‐​sacred status, has been able to control public opinion to a degree that exceeds the power of the most despotic monarch.

This concern with the potentially deleterious effects of democratic opinion on freedom of thought also was expressed in J. S. Mill’s “On the Liberty of Thought and Discussion,” a seminal chapter in On Liberty (1859). In addition to legal freedom, Mill emphasized the need for “diversity of opinion” and the need for personal toleration of unorthodox beliefs in maintaining the social conditions of a free society.

Further Readings

Bacon, Francis. The Major Works. Brian Vickers, ed. New York: Oxford University Press, 2002.

Collins, Anthony. A Discourse of Free‐​Thinking. New York: Garland, 1978.

Descartes, René. Discourse on Method and Meditations on First Philosophy. Indianapolis, IN: Hackett, 1998.

Locke, John. “A Letter Concerning Toleration.” The Works of John Locke in Nine Volumes. vol. 5. 12th ed. London: Rivington, 1824.

Mill, John Stuart. “On the Liberty of Thought and Discussion.” On Liberty. London: J. W. Parker and Son, 1859.

Milton, John. Areopagitica and Other Political Writings of John Milton. John Alvis, ed. Indianapolis, IN: Liberty Fund, 1999. Orwell, George. 1984. New York: Harcourt, 2000.

Spencer, Herbert. Social Statics: or, the Conditions Essential to Happiness Specified, and the First of Them Developed. London: John Chapman, 1851.

Tocqueville, Alexis de. Democracy in America. Harvey C. Mansfield and Delba Winthrop, eds. Chicago: University of Chicago Press, 2000.

George H. Smith
Originally published