Within the libertarian tradition, equality has primarily signified an equality of individual rights. This idea, which took centuries to develop, owed a good deal to post- Renaissance interest in the ancient philosophies of Stoicism and Epicureanism.

Stoics, working from the premise that all human beings possess the faculty of reason, maintained that each individual had an equal ability to live a virtuous life. Epicurus and his followers were early proponents of a social contract, a hypothetical model in which every individual has self-interested reasons to respect the equal rights of every other individual. Also important, especially in Anabaptist, Quaker, and other radical offshoots of Reformation thought, was the Christian doctrine that all human beings are equal in the sight of God.

The democratic implications of a theory of equal rights came to the fore in England during the 1640s, the era of the English Civil Wars. Libertarians such as John Lilburne, Richard Overton, and William Walwyn defended religious freedom (in some cases even for atheists), free trade, the rights of private property, and government by consent. Ironically perhaps, these libertarians are still known as Levellers, originally a term of opprobrium given to them by their political enemies who accused them of wishing to level all differences of property.

In fact, the Levellers were opposed to any kind of egalitarian socialism. While defending private property, based on the natural right of self-proprietorship, they rejected the doctrine that substantial property holders—especially in land—should enjoy special political rights. As Colonel Rainborough put it during the “Putney debates,” a public exchange between the Levellers and Cromwellians: “For I really think that the poorest he that is in England hath a life to live, as the greatest he … that the poorest man in England is not at all bound in strict sense to that government that he hath not had a voice to put himself under.”

The most influential statement of what later became the libertarian theory of equal rights appeared in John Locke’s Second Treatise of Government. According to Locke, “all Men are by Nature equal.” The state of nature (that “State all Men are naturally in”) is not only a “State of perfect freedom,” but “a State also of Equality, wherein all the Power and Jurisdiction is reciprocal, no one having more than another… .” The most fundamental among these equal rights is the right of every individual “to his own Person, which no other man has power over, but the free Disposal of it lies in himself.”

The import of Locke’s notion of equal rights may be described as political reductionism. This theory states that all rights and powers claimed by government must ultimately be reducible to the equal rights and legitimate powers of individuals as they would exist in a state of nature. Equal rights can be transferred, delegated, or alienated only through consent, according to Locke. Therefore, no person can lay claim to a natural privilege of sovereignty, which supposedly entitles him or her to rule others without their consent. Nor (as Samuel Pufendorf and others had argued) can a government lay claim to special rights that no individual could possibly possess.

Locke’s theory of equal rights had radical implications that would later manifest themselves in the American and French Revolutions. But even critics of these revolutionary tendencies would often defend some version of equal freedom with a distinctively Lockean flavor. For example, according to Edmund Burke,

[Social] liberty … is that state of things in which liberty is secured by the equality of restraint. A constitution of things in which the liberty of no one man, and no body of men, and no number of men, can find means to trespass on the liberty of any person, or any description of persons, in the society.

Similarly, Immanuel Kant, after defining freedom as “independence from the constraint of another’s will,” argued that authentic freedom must be “compatible with the freedom of everyone else in accordance with a universal law.”

This idea received one of its most influential formulations in Herbert Spencer’s “Law of Equal Freedom” (in Social Statics, 1851). According to Spencer, “Every man has freedom to do all he wills, provided he infringes not the equal freedom of any other man.” The “freedom of each must be bounded by the similar freedom of all,” and “every man may claim the fullest liberty to exercise his faculties compatible with the possession of like liberty by every other man.”

This approach to equal rights stands in stark contrast to various doctrines of egalitarianism as this term is commonly understood. For instance, in Power and Market (1970), the libertarian economist Murray Rothbard argues that “the diversity of mankind is a basic postulate of our knowledge of human beings,” so “it can be shown that equality of income is an impossible goal for mankind.” Egalitarianism is “a literally senseless social philosophy.”

Another libertarian critique of egalitarianism, one that has profoundly influenced the course of contemporary political theory, appears in Robert Nozick’s Anarchy, State, and Utopia (1974). Nozick criticizes “welfare economics” and other theories of egalitarianism that are defended in the name of “distributive justice,” defending instead what he calls an “entitlement theory” of justice.

A libertarian theory of justice is not patterned or coercively imposed according to some notion of end results. According to Nozick, the “entitlement theory of justice in distribution is historical; whether a distribution is just depends upon how it came about.” If property titles were originally acquired by just means and if they have since been transferred voluntarily, then the resulting state of affairs is just even if it does not conform to the moral ideal of social planners. Hence, “The entitlement conception of justice in holdings makes no presumption in favor of [material] equality, or any other overall end state or patterning. It cannot merely be assumed that equality must be built into any theory of justice.”

Further Readings

Cicero, Marcus Tullius. On Duties. M. T. Griffin and E. M. Atkins, eds. Cambridge: Cambridge University Press, 1991.

Locke, John. Second Treatise of Government. Peter Laslett, ed. Cambridge: Cambridge University Press, 2005.

Lucretius. On the Nature of Things. Frank O. Copley, trans. New York: W. W. Norton, 1977.

Nozick, Robert. Anarchy, State, and Utopia. New York: Basic Books, 1974.

Rothbard, Murray. Power and Market. Kansas City, MO: Sheed Andrews & McMeel, 1970.

Sharp, Andrew, ed. The English Levellers. Cambridge: Cambridge University Press, 1998.

Spencer, Herbert. Social Statics. London: Chapman, 1851.

Vonnegut, Kurt. “Harrison Bergeron.” Welcome to the Monkey House. K. Vonnegut, ed. New York: Dial Press Trade Paperbacks, 2006.

———. The Sirens of Titan. New York: Dial Press Trade Paperbacks, 2006.