I thank Hyrum Lewis for his lucid response to my criticism of his theory of the ideological spectrum. His article helped me realize that we have mostly been speaking past each other. I now believe that our respective theories of the left/right political divide are not necessarily at odds; they are simply trying to explain different things. While he is interested in explaining the causal process by which Americans today adopt their political beliefs, I am interested in discovering what philosophical principle — if any — unites the social movements, politicians, and political ideas that have been designated left-wing or right-wing across time and space.

Lewis is a proponent of what he calls the “social theory of ideology,” which claims that contemporary Americans on the left and right arrive at their beliefs by “anchoring into a political tribe, adopting all the positions of that tribe as a matter of socialization, [and] inventing a story to explain how all those positions grow out of a single essence.” He believes that this theory of ideology is superior to what he calls the “essentialist theory of ideology,” which holds that people come to their beliefs by adopting some essential principle (equality, liberty, etc.), deriving a set of political prescriptions from it, and then joining the political tribe that supports those prescriptions.

So Lewis’ social theory of ideology attempts to provide an account of a causal process, and although I am not an empirical social scientist, Lewis’ account seems right to me.

Instead, I defend a theory of the ideological spectrum that claims the left is characterized by a commitment to egalitarianism (that is, to the promotion of equality) and the right by (1) opposition to equality and (2) support for some value other than equality. The value that rightists place above equality depends on the kind of right we are talking about. The modern libertarian right, for instance, might value individual freedom or economic prosperity more highly than economic equality; the traditionalist right might value faith and political stability more than social equality; and so forth. What unites most versions of the right is that they reject the egalitarian claims of the left because they find some other value to be more important. The left/right ideological spectrum thus describes one axis of political conflict — the axis of equality — but does not describe the entirety of the political landscape, since not all political conflicts concern equality (more on this shortly).

Unlike Lewis’ social theory of ideology, this “equality theory of the ideological spectrum” is not a causal theory about why individual people come to hold the views they do. It is rather an analytical theory whose purpose is to illuminate what it means to call something right-wing or left-wing. Let me now make some clarifications about what this theory says and does not say.

As the Italian philosopher Norberto Bobbio has argued, the terms “left” and “right” are relative to time and place. To describe something as left-wing is to say that it is comparatively more egalitarian than the right-wing movements of its historical context. “When we say the left has a greater tendency to reduce inequalities,” Bobbio writes, “we do not mean that it intends to eliminate all inequalities, or that the right wishes to preserve them all, but simply that the former is more egalitarian, and the latter more inegalitarian.”

Bobbio explains that the meaning of equality is also relative, not absolute. As he puts it, equality is “relative to at least three variables: the individuals between whom benefits and obligations should be shared; (b) the benefits or obligations to be shared; (c) the criteria by which they should be shared.” The extent to which a given idea or policy is egalitarian can be ascertained by asking “the following three questions: between whom? Of what? On the basis of what criteria?” The left will tend to give more-egalitarian answers to these questions than the right: It might demand that equality be extended to more groups of people, or it might demand greater equality of resources, status, power, or rank, or it might call for a more egalitarian criteria by which to distribute benefits or rights.

Consider the French Revolution. Supporters of the Revolution believed that the privilege of the aristocracy and the absolute power of the monarchy were unjust forms of inequality, and they wanted to abolish them. These beliefs made them more egalitarian than French counterrevolutionaries, who were more supportive of noble privilege and royal prerogative. The French revolutionaries are thus accurately regarded as left-wing, just as the French counterrevolutionaries are accurately regarded as right-wing.

One can think of other examples that confirm the equality theory of the ideological spectrum. Bobbio points to the example of Chartism, a working-class reform movement from nineteenth-century Britain, which is correctly perceived as left-wing because it demanded universal manhood suffrage at a time and place when only wealthier men could vote. Another example would be the political parties of the contemporary United States. Democrats are rightly considered to be more left-wing than Republicans, since they are comparatively more egalitarian: Their political program is to a greater degree committed to the eradication of inequalities, especially on the basis of race, gender, and class.

The essence of the left is that it tends toward more equality, and the essence of the right is that it tends against it and prioritizes different values over it. Again, this is not a claim about the process by which people form their political views. It is a claim about the conceptual framework by which political views are organized into a spectrum. Views that promote equality in their given time and place are on the left, and views that oppose the claims of equality and promote some other value above it are on the right.

The equality theory of the political spectrum explains one way in which political movements and ideas differ from each other — namely by the extent to which they support or oppose equality. But not all political conflicts can be thought of as struggles over equality, so political issues cannot always be neatly divided into conflicts between left and right. The current American debate over gun control, for instance, has nothing to do with equality. Supporters of more-stringent gun regulation generally believe that such regulation will reduce or eliminate gun violence, while critics generally believe that it would not do so and that gun control is, in any case, a violation of the Second Amendment. Since this debate does not concern equality, the two positions (pro- or anti-gun control) cannot be meaningfully described as left-wing or right-wing, even if those on the left tend to support gun control and those on the right tend not to.

Moreover, equality is not the only value people care about and fight for. Another such value is political liberty, defined here as the ability to participate in democratic self-government. There is no necessary connection between one’s belief in democracy and the extent to which one supports equality. The proof of this is that people on both the left and right have historically supported dictatorships — think respectively of the Soviet Union and of Chile under Augusto Pinochet. People on the left and right have also supported democracy, as the center-left and center-right parties of Europe do today.

It is wrong, then, to think that there are only two sides to every political conflict — a right side and a left side. Some issues are unrelated to the left/right distinction (for they do not concern equality), and both the left and right come in many different varieties. There are moderates and radicals on both left and right, and there are democrats and autocrats on both left and right. The ideological spectrum describes and illuminates a certain part of political life without fully capturing the entirety of it.

Thus, although I share Hyrum Lewis’ view of how contemporary Americans form their political beliefs, I cannot agree with his claim that the political spectrum “doesn’t even exist” and that we would be better off not referring to things in terms of left and right. The political spectrum is a helpful and meaningful analytical framework that allows us to understand conflicts over equality, which have been so important in modernity (i.e., since the French Revolution). For that reason we should continue to use it, even as we recognize that not every political question has to do with the quarrel between left and right.