As is true of many seventeenth-century philosophers, John Locke’s interests span the disciplines that comprise the modern natural and social sciences. His most famous contribution to the history of political thought is his lucid articulation of the theoretical foundation of modern liberalism in his Two Treatises of Government and A Letter Concerning Toleration. He also made important contributions to economics, psychology, and education.

The Origins of Government

Locke was not the first philosopher to invoke a “state of nature” in his account of the origins of government, but his state of nature in the Second Treatise merits comparison to previous incarnations of the idea, and in particular to Thomas Hobbes’s use of the term in Leviathan. Locke claims that life in the state of nature was “a state of perfect freedom” as well as equality and plenty, lacking only “a common…authority to judge between them.”

Man in the state of nature possesses several rights by the law of nature, the most fundamental of which is the right of self-preservation, from which follows what Locke calls his “strange doctrine” that everyone in the state of nature has the right to punish offenders against that law without recourse to a higher magistrate or judge. Anyone who offends against the law of nature “puts himself into a state of war” against the rest of humanity, permitting anyone to punish him to the extent they judge necessary, including of course by death. So, although Locke’s state of nature seems at first more pleasant than Hobbes’s, this universal power to execute the law of nature soon leads to irresolvable conflict.

Because everyone is born equal and free, any form of rule over him requires his consent to be legitimate. Society thus originates from a social contract. The purpose of forming and submitting to government is to secure the individual rights to life, liberty, and property. Locke claims that citizens cannot fully give up their authority to judge whether government is so infringing on their rights that it is acting tyrannically and must be opposed.

The Right to Revolution

In the final chapter of the Second Treatise, Locke lays out an account of the causes of the dissolution of a government, and in a departure from prevailing opinion about the rights of subjects, affirms the right of citizens to resist a tyrannical government. Locke’s ideas differ both from earlier thinkers such as Hobbes, who denied subjects any right to resist their sovereign, and those such as John Calvin, who admitted that tyrants ought to be deposed but denied ordinary citizens the right to depose them, instead entrusting this task to magistrates. Approximately a decade before the publication of the Second Treatise, Algernon Sidney had advanced a position on rebellion similar to Locke’s in his Discourses Concerning Government, a book that resulted in his execution for treason. Both Sidney’s and Locke’s writings on this question were influential in the American Revolution. Several passages in the Declaration of Independence directly echo Locke’s formulations in the Second Treatise.

Locke argues that if the legislature changes its form against the will of the majority, or if the executive suspends or abolishes it, then the legislative power is sufficiently altered as to be considered dissolved. The people are then released from their original contract and “at liberty to provide for themselves…by erecting a new legislative.”

Anticipating objections to this doctrine, and particularly the accusation that it would encourage the people to revolt frequently and without due cause, Locke insists that this right of resisting arbitrary power will be used only as a last resort: “Great mistakes in the ruling part, many wrong and inconvenient laws, and all the slips of humane frailty will be born by the people, without mutiny or murmur. But if a long train of abuses, prevarications, and artifices, all tending the same way, make the design visible to the people, and they cannot but feel, what they lie under, and see, whither they are going; ‘tis not to be wonder’d, that they should then rouze themselves, and endeavor to put the rule into such hands, which may secure to them the ends for which government was at first erected.”

Locke further denies that the people act inappropriately as judges of their own case—a power they were required to surrender on their entrance into political society—when they revolt against their rulers. The right to determine the validity of citizens’ grievances against the government rests with the people, and if the government denies the people’s judgment, “the appeal lies nowhere but to Heaven…and in that state the injured party must judge for himself, when he will think fit, to make use of that appeal.”

Labor and Property

The fifth chapter of the Second Treatise introduces Locke’s original theory of the origin and nature of property. Although some had argued that there could be something like a natural basis to property, most theorists (including Hobbes and, later, Rousseau) argued that property could not exist in nature, and could only come into being after the state was formed. Locke rejects this view, and offers in its place an account of property according to which property is the impetus for establishing a state, rather than its result. The unequal distribution of property within a state can ultimately be justified by natural right rather than merely by positive law.

Locke’s account begins with the assertion that the state of nature is a state of plenty, and stocked by God with more than enough to sustain every individual in it, so that no man’s appropriating anything from this common stock was “any prejudice to any other man, since there was still enough, and as good left.” The individual acquires property in nature by “mixing his labor” with natural objects—collecting acorns, for example, or planting seeds. But to ensure that there would be enough and as good for the next man, his acquisition was originally limited by the law of nature that permits the acquisition of only “as much as any one can make use of to any advantage of life before it spoils.” However, this does not ensure that all men acquire equal property, for men are not by nature equally intelligent or diligent: “God gave the world to men in common; but since he gave it them for their benefit, and the greatest conveniencies of life they were capable to draw from it, it cannot be supposed he meant it should always remain common and uncultivated. He gave it to the use of the industrious and rational.”

The invention of money further exacerbates but also justifies the disparities in property among men. Money permits men to circumvent the natural prohibition against acquiring more than one can use before it spoils, because money itself and the objects in which its value is stored never spoil, while the valuation of things such as gold and silver is a matter of universal consent. By this means, “men have agreed to disproportionate and unequal possession of the earth, they having by a tacit and voluntary consent found out a way, how a man may fairly possess more land than he himself can use the product of.”

Before being improved by human labor, moreover, nature is worth little, “for ‘tis labor indeed that puts the difference of value on every thing; and let anyone consider, what the difference is between an acre of land planted with tobacco or sugar, sown with wheat or barley; and an acre of the same land lying in common, without any husbandry upon it.” Locke develops in characteristically subtle fashion his argument that labor, not nature, is the almost complete source of value.

Finally, Locke’s doctrine of property elevates its priority both in the foundation of states and as an end for politics. Private property exists in the state of nature, but without a common judge to preside over violations against it, remains very insecure. The effort to secure their property is one of the primary motivations for men to establish a government, and the primary purpose of that government is, in turn, to protect that property: “The reason why men enter into society, is the preservation of their property, and the end why they chuse and authorize a legislative, is, that there may be laws made, and rules set as guards and fences to the properties of all the members of the society, to limit the power, and moderate the dominion of every part and member of the society.” For Locke, the protection of property preserves the rights to life and liberty by fencing off a private sphere free from government and other men. Indeed, one of the criteria for tyranny is the government’s unlawful confiscation of property. Locke’s defense of private property became one of the central tenets of classical liberalism.

Toleration

Locke wrote several “letters” for publication defending a broad government policy of religious toleration for dissenters from the state church, the first and most well-known of which was published anonymously in 1689. Locke’s basic position against enforcing religious uniformity had been advanced by some earlier thinkers such as Spinoza and Milton, who were faced with the same intractable conflicts created by the Protestant Reformation. However, toleration as government policy had been rare and often short-lived in Europe. England’s Toleration Act of 1689 was characteristic of the limited settlements that states reached with their religious dissenters. The Act permitted all Trinitarian Protestants to worship publicly if they signed an oath of allegiance, but non-Anglicans still could not hold public office. Although Locke agreed that Catholics and professed atheists were too politically dangerous to tolerate, his own case for toleration was much broader than the Act’s permissions. Locke’s articulation of the reasons for toleration has become particularly influential for modern liberal-democratic thought and remains one of the foundations of American thinking about church-state relations and First Amendment jurisprudence.

In his 1689 Letter, Locke offers both principled and prudential reasons for tolerating religious dissenters. The foundational point from which his argument proceeds is that sincere Christian faith can only arise by a voluntary act of an individual’s private will, and so can never be externally coerced. He argues that “the care of men’s souls cannot belong to the civil magistrate, because his power consists only in outward force; but true and saving religion consists in the inward persuasion of the mind.” While the threat of punishment can persuade people to act in outward conformity with the state religion, such punishments cannot bind men’s consciences or turn their hearts toward the true faith. They instead turn them against the government that persecutes them, and undermine the Christianity of those who impose these measures, because the imprisonment, torture, and execution of those whose souls one sets out to save is not in keeping with the Christian call to charity and humility.

Locke draws a sharp distinction between the duties of civil and ecclesiastical authorities, which is the forerunner of our contemporary doctrine of the separation of church and state. (We should note, however, that Locke was not arguing for the disestablishment of England’s state church, only for limitations on its authority over civil affairs). The civil magistrate’s task is to “secure…the just possession of these things belonging to this life,” whereas a church is a voluntary body whose aim is “the publick worshipping of God, in such a manner as they judge acceptable to him, and effectual to the salvation of their souls.” Each power thus presides over its sphere by its own means. Churches are not obligated to admit or retain members who deny their tenets, but they cannot inflict any legal punishment on those who deviate from them. Their powers are limited to persuasion and admonition, since coercion of the conscience is always impossible anyway. Legal compulsion regarding only “things indifferent”—that is, things unconnected with religious doctrine and observance—is reserved for the civil authority.

This general separation of civil and ecclesiastical authority permits Locke to argue for broad legal toleration of competing religious doctrines, including Judaism, Islam, and even paganism. “No man whatsoever ought to be deprived of his terrestrial enjoyments, upon account of his religion.” Nonetheless, all is not permitted under cover of religion, and Locke imposes certain limitations on what the civil laws should be expected to tolerate. The first is that, although the government cannot prescribe the doctrine or ceremonies of any church, it can proscribe practices that “are not lawful in the ordinary course of life nor in any private house” and transgress the basic conventions of the civil society, such as human sacrifice. Locke’s second limitation on toleration concerns religious doctrines “contrary to human society, or to those moral rules which are necessary to the preservation of civil society.” This includes the doctrines of those Catholics who “deliver themselves up to the protection and service of another prince” and so can never be trusted to be loyal subjects of any civil government. It also includes atheists, because their denial of God means that “promises, covenants, and oaths, which are the bonds of humane society, can have no hold upon an atheist.”

Epistemology and Psychology

Locke’s Essay Concerning Human Understanding is one of the earliest and most important statements of modern empiricism, the view that all human knowledge derives from sense perception. Arguably the most famous part of the Essay is the first book, which is an extended attack on the possibility of “innate ideas.” Locke compares the human mind at birth to an “empty cabinet” or a “white paper,” possessing only certain instinctive passions such as pleasure and pain, but no ideas about physical or moral things. (Although he comes close to calling the mind a tabula rasa or “blank slate,” these are not actually Locke’s words.)

In the Essay’s subsequent books, Locke argues that sensation and reflection are the two basic components of the understanding, which is built up first by collecting “simple ideas”—basic sensory qualities of objects such as “hot,” “blue” “soft,” and so on—and then reflecting on them in our minds, linking them together to form complex ideas. A parallel development occurs in the realm of abstract ideas (Locke calls these “modes”) such as mathematics and moral precepts. Our minds begin from simple modes like space, duration, and number, and they combine these to arrive at complex and mixed modes such as geometry and justice. Language then serves as a way to arrange and communicate our ideas, but it also introduces many errors into our thinking.

In addition to thinking, the other faculty of the mind is volition or willing, and it is with respect to the freedom of the will that Locke makes a novel contribution to psychology. Locke argues that desire, an “uneasiness of the Mind for want of some absent good…determines the Will to the successive voluntary actions whereof the greatest part of our Lives is made up.” Indeed, satisfaction of desire is relief from uneasiness, and such relief is the heart of happiness. Government that secures rights and the growth of property advances the satisfaction of desires and thus increases happiness. Although the will is ultimately moved by the “greater uneasiness,” however, this need not be the greatest present unease. For the mind is equipped with a “power to suspend the execution and satisfaction of any of its desires.” It is in this state of detached consideration of our options, something that is perhaps most visible among the rational and industrious of whom Locke speaks in the Second Treatise, that “lies the liberty Man has, and from the not using of it right comes all that variety of mistakes, errors, and faults we run into.”

Locke’s epistemology and psychology elevate the importance of individual effort in cultivating the understanding while radically demoting the power of authority, including perhaps especially religious authority, over the mind. True understanding is only available to us through our own senses and the reflective process of our minds, so we can never really know something second-hand.

Education

Some Thoughts Concerning Education fills a gap in the political theory that Locke lays out in the Two Treatises by showing how “natural freedom and subjection to parents may consist together”–that is, how the child who is born free but not reasonable becomes reasonable enough to exercise his freedom as a full citizen. This is an especially important question precisely because of the limitations on government established in the Second Treatise: where the civil law is to have only limited prescriptive power over the private lives of citizens, it becomes increasingly important to inculcate self-restraint and self-discipline that prevent the abuse of liberty. Education in Locke is elevated beyond its narrow sense as academic training and returned to its ancient status as a tool for the cultivation of citizenship, so much so that, where faced with a choice between the two ends, Locke chooses the latter:

Reading and writing and learning, I allow to be necessary, but yet not the chief business. I imagine you would think him a very foolish fellow that should not value a virtuous or wise man infinitely before a great scholar…Learning must be had, but in the second place, as subservient to greater qualities.

Locke’s curriculum follows from many of his psychological ideas in the Essay and is based in part on his experience as a tutor to the third earl of Shaftesbury. Its major principle is that education should take account of, and indeed manipulate, the child’s perceptions of pain and pleasure, so that through habituation, he eventually internalizes the correct standards of good behavior and learns to govern himself. Locke warns against both coddling and corporal punishment as two popular but dangerous modes of childrearing—the former because it exacerbates a child’s natural willfulness and desire for “mastery,” the latter because it either suppresses his desires so much that it leads to a slavish disposition or tempts him towards violence and cunning. Rather than physical rewards and punishments, Locke urges the use of “esteem and disgrace” to inculcate good behavior, an application of “the law of fashion and reputation” from the Essay:

Children (earlier than we perhaps think) are very sensible of praise and commendation. They find a pleasure in being esteemed and valued, especially by their parents and those whom they depend on…Concerning reputation…though it not be the true principle and measure of virtue…yet it is that which comes nearest to it; and being the testimony and applause of other people’s reason, as it were by common consent…it is the proper guide and encouragement of children, till they grow able to judge for themselves and to find what is right by their own reason.

Because children are so desirous of praise from the adults around them, and because “children (nay, and men too) do most by example,” it is urgent that they be kept in virtuous company and away from bad moral influences, including notably, the influence of other children. To avoid such influences, Locke recommends that children be instructed at home by a tutor rather than in schools. Locke’s (and later, Rousseau’s and John Stuart Mill’s) hesitation about the influence of both private and government schools makes an interesting contrast to modern liberalism, which often assumes the necessity of public schooling.

Locke’s recommendations for academic training parallel his broader view of the importance of winning the child’s will without the use of force. He criticizes the traditional Latin curriculum for being harsh and ill-adapted to the minds of children, with its emphasis on complex grammar and rules, and suggests instead that they be taught to read and write in their own languages first, and in such a way that “learning might be made a play and recreation to children, and that they might be brought to desire to be taught.” When they do move on to language instruction, including Latin, they ought to be taught through speaking the language rather than rote memorization of grammatical rules. The use of games and pleasures to induce children to study predates Locke, but has largely made its way into modern pedagogy through him.

For further introductory reading, see:

Robert Goldwin, “John Locke,” in History of Political Philosophy, Eds. Leo Strauss and Joseph Cropsey, Chicago: 1987.