Ludwig von Mises argued that the “nineteenth century philosophy of liberalism,” or the classical tradition of liberalism, is not founded on equality but on liberty. He rejected the notion that all men are factually or substantively equal. He saw the notion of substantive equality—what is sometimes called real equality or true equality—as incompatible with individual liberty, and as a Trojan horse for coercive interventionist schemes designed to equalize all members of society. He saw liberty as essential to peaceful coexistence and to Western civilization itself. Thus, Mises took seriously the threat posed to peace and prosperity by the egalitarian schemes with which governments aim to equalize all their citizens. In his book Liberalism, he traced the roots of the erroneous belief in equality to the Enlightenment:
The liberals of the eighteenth century, guided by the ideas of natural law and of the Enlightenment, demanded for everyone equality of political and civil rights because they assumed that all men are equal.…
Nothing, however, is as ill-founded as the assertion of the alleged equality of all members of the human race. Men are altogether unequal. Even between brothers there exist the most marked differences in physical and mental attributes. Nature never repeats itself in its creations; it produces nothing by the dozen, nor are its products standardized.
Similarly, Friedrich von Hayek rejected the idea that the classical liberal ideal of justice is based on equality. He argued in the Constitution of Liberty that justice must be based on individual liberty, which is not predicated on a presumption that everyone is equal. He cautioned that “we must not overlook the fact that individuals are very different from the outset…. As a statement of fact, it just is not true that ‘all men are born equal.’” Murray Rothbard picked up this theme in Egalitarianism as a Revolt against Nature, arguing that a world in which all human beings are equalized by state coercion and force would be a Procrustean world of horror fiction. He asked:
What, in fact, is “equality”? The term has been much invoked but little analyzed. A and B are “equal” if they are identical to each other with respect to a given attribute. Thus, if Smith and Jones are both exactly six feet in height, then they may be said to be “equal” in height… There is one and only one way, then, in which any two people can really be “equal” in the fullest sense: they must be identical in all of their attributes.
Yet Hayek, like Mises, defended the principle of equality before the law. Although they both rejected the notion of substantive equality, they argued that formal equality—or equality before the law—is essential to social cooperation under the rule of law. If equality under the law is not based on factual equality, on what is it based? It may seem contradictory to uphold formal equality while rejecting substantive equality, but, as Hayek explained, substantive equality actually undermines formal equality because it fails to acknowledge the very reason why formal equality is important. Justice in the classical liberal ideal was described as blind, not because there are no differences between people, but because justice is blind to their differences. The principle of blind justice is completely lost when people assume that we can only have the same rights when we are, in fact, the same, and that everyone has to be made the same through whatever interventions can make them equal, in order to align with the fact that we all want to have equal rights. The reason justice is blind is because that is the best way to maximize the scope of individual liberty. Under blind justice, nobody is subjected to legal obligations or penalties to which others are not subject, based purely on his personal identity or characteristics. As Hayek put it, “Nothing, however, is more damaging to the demand for equal treatment than to base it on so obviously untrue an assumption as that of the factual equality of all men.” Both Mises and Hayek saw individual liberty as the only rationale for formal equality, and insisted that equality under the law is the only form of equality that is compatible with liberty. In his book Liberalism, Mises argued that:
…what [liberalism] created was only equality before the law, and not real equality. All human power would be insufficient to make men really equal. Men are and always will remain unequal.… Liberalism never aimed at anything more than this.
One might ask why the law should bother to uphold formal equality, or equal treatment under the law, if people are not, in fact, equal. Mises gave two reasons. The first reason is that individual liberty is essential to social cooperation. He argued that individual liberty is justified because it promotes the good of the whole, and that classical liberalism “has always had in view the good of the whole, not that of any special group.” The good of the whole can only be achieved through social cooperation, and there can be no social cooperation where men are not free. He defined society as “an association of persons for cooperative action,” and cooperation is maximized when people are free to engage in peaceful and voluntary exchange based on the division of labor. The good of the whole, and social cooperation, are in turn dependent on individual liberty and private property rights. Mises saw this as the essential distinction between classical liberalism and socialism:
Liberalism is distinguished from socialism, which likewise professes to strive for the good of all, not by the goal at which it aims, but by the means that it chooses to attain that goal.
The second reason is “the maintenance of social peace.” Mises argued that peaceful co-existence is essential to civilization and prosperity, and requires that everyone must have the same rights under the law. A legal system which gives special privileges to one group at the expense of another leads inevitably to resentment, hostility, conflict, and ultimately war. Mises argued that “class [or group] privileges must disappear so that the conflict over them may cease.” Similarly, Rothbard emphasized that egalitarian schemes lead inexorably to conflict, warning that any society which sets out to produce equality sets off down the road to tyranny: “An egalitarian society can only hope to achieve its goals by totalitarian methods of coercion.”
Socialists object to the classical liberal notion of formal equality by arguing that if men are not, in fact, equal then the law ought, as far as possible, to at least try to make men equal. They suggest achieving this by abolishing any privileges enjoyed by some that are not available to others, or by creating special rights for those who lack the privileges enjoyed by others, to compensate for their disadvantages. Mises rejected this notion of “privilege.” What a man earns from his skill or talent, what is acquired under the rules of private property, cannot be deemed to be a “privilege,” because it is justified as necessary for social cooperation and the good of the whole:
The fact that on a ship at sea one man is captain and the rest constitute his crew and are subject to his command is certainly an advantage for the captain. Nevertheless, it is not a privilege of the captain if he possesses the ability to steer the ship between reefs in a storm and thereby to be of service not only to himself, but to the whole crew.
Mises therefore saw formal equality, or equality under the law, as an essential component of liberty. His defense of liberty was, in turn, based on the fact that liberty is essential to human flourishing. The significance of liberty as the philosophical foundation of equality is clear—it follows that any equality “rights” that undermine individual liberty are invalid. They are indeed phony rights, as Rothbard put it.