Debatability outweighs—shared understanding of the conceptual horizons of the topic allows us to work out internal contradictions and achieve higher levels of understanding—that’s a prerequisite to the capacity to critique societal norms and institutions in the first place. There’s no offense, it’s T, not framework—we’re agnostic about content because entering in debate means accepting you could be wrong—but the form of debate demands a common criterion for internal coherence that alternative roles for the ballot make impossible.

Deciding between competing understandings of the same issue through reasoning necessitates a good deal of common understanding. This common ground is partly epistemological—an (implicit or explicit) consensus on what counts as good reasons, valid arguments, and so forth—and partly in the form of some overlap in conceptual horizons: the fundamental categories through which the issue is understood.

Philosophers have used different terms for this conceptual horizon, such as “background” (Searle 1995, chap. 6), “paradigm” (Kuhn 2012, chap. 2), “inescapable framework” (Taylor 1989, chap. 2), or “world view” (Weber 2004, 103). Regardless of the particular term one prefers, the main point—now ubiquitous in modern philosophy—is that we human beings inescapably relate to the world, to ourselves, and to others through conceptual lenses of which we might be more or less conscious.

Kuhn, famously, pointed out that even when we seemingly have an external standard of reference, such as when observing physical objects, we still rely on a shared conceptual framework in order to agree on what we are seeing: “a paradigm is prerequisite to perception itself” (Kuhn 2012, 113). Kuhn’s scientific paradigms are but one example of a general phenomenon that extends also to political philosophy and ideology. Before Kuhn, Karl Mannheim, known as the founder of the sociology of knowledge, argued that having different ideologies—being, say, a liberal, a Marxists or a fascist—amounted to comprehending the world very differently, even incompatibly (Mannheim 1997). Ideological divisions, Mannheim argued, reached all the way down to the very meaning of words.

Just as a Aristotelian and a Newtonian physicist would not mean the same thing when speaking of “force”—and a Newtonian and an Einsteinian physicist would not mean the same thing when speaking of “space” and “time”—a liberal and a Marxist would not mean the same thing when speaking of concepts like “liberty.”8 A Lockean liberal for whom “private property is […] the natural expression and realization […] of individual freedom” (Scruton 2017)—and who sees the chief end of political society to protect that property (Locke 2009, 97)—might find it absurd to learn that Marxists envision a society without private property as the final emancipation of man.9

The issue, of course, is that word the “liberty” has different meanings and different relations to other values in different political philosophies and ideologies. It is not the case that liberals believe in liberty and Marxists believe in something else. It was not freedom that Marx sought to abolish but the oppression of the working class, which, according to him, was ideologically justified by “bourgeois” concepts of freedom, such as we find in Locke and in the liberal constitutions in Marx’ own time (see e.g. Marx 1994: 17–20).

Real freedom, Marxists have always argued, is economic freedom, which, for classical Marxism/socialism at least, rests on ownership of the means of production. Consequently, universal emancipation means communism and collective ownership of land, factories, and resources—the exact opposite of the liberal conclusion. Obviously, if a consensus on fundamental political principles is ever to be obtained among liberals and Marxists, a consensus of meaning must be established first. (And foreshadowing a second point: such a consensus would change the ideological positions involved, insofar as the content of an ideology is partly defined by the meaning of its central concepts.)

That people use the same word to mean different things in political discourse obviously makes communication difficult, but I would contend that the fact that everybody claims to be the proper interpreters of the same values such as “freedom” actually carries a good deal of hope. This transforms at least some political value conflicts into conceptual conflicts. And if we can translate (at least some of) our fundamental ideological differences into conceptual issues, then we can potentially handle these difference within the domain of reason.

Dialectical argument

What I have portrayed above would be a case of what Mouffe calls a “conflictual consensus”—”consensus on […] ethico-political values […], dissent about their interpretation” (Mouffe 2005, 121)—which is a form of “agonistic” relation that a democracy is supposed to be able to handle. How, however, should we handle them? If we want to handle such disagreement through reasoning and deliberation, the circumstance that we lack a consensus on meaning is an obvious obstacle. How can we talk to each other if we use words differently? And in what sense can we really be said to have a consensus on, say, the importance of human liberty if we have deeply conflictual interpretations of “human liberty”—especially when these differing interpretations translate into radically different visions for political society?

It seems that focusing less on the expression of values and more on their interpretation—less on the use of words, such as “liberty,” “equality,” and “democracy,” and more on the meanings of those words—could be fruitful. Once we realize that these political values are conceptualized very differently in different ideologies, we can no longer take their meaning as self-evident. This circumstance necessitates self-reflection—“reasoning through cross-examination and the constant repositioning of one’s thought” (Brincat 2014, 590)—which is the driving force of dialectical argument.

Most theoretical positions have internal inconsistencies or contradictions as they are often referred to in dialectical parlance (we will find such contradictions in both liberalism and Islamism in the next section), which often come to light only when confronted with alternative ways of thinking.10 The working out of these contradictions usually has a transformative effect. At the end of a truly dialectical process, neither side rarely find themselves in the exact same theoretical position they had at the beginning. Conversion is, of course, a possibility—so is synthesis. At the very least one can expect more robust versions of the original positions, even perhaps amounting to new positions, insofar as fundamental parts of one’s conceptual apparatus may have been altered in the process.

The possibility of progress in political–philosophical argument

A crucial premise for dialectic reasoning is that reasoning, if done properly, can move subjects not only towards a common understanding, but also—as an integral part of that process—from lower to higher levels of understanding. A higher level of understanding entails a better grasp of issues that could not be properly dealt with within a lower-level paradigm. One example from the natural sciences is how Einsteinian physics—the higher-level position in this example—can account for the discrepancies in the orbit of Mercury that Newtonian physics—the lower-level position—could not account for, by changing the fundamental conceptual apparatus of physics.11

When comparing positions in political philosophy, the situation is more complicated than in the case of physics in (at least) two important ways. First, in the Einstein–Newton example there exists a clear criteria, common to both paradigms, can serve as an “umpire” in Gaus’ terms, namely the purpose and principles of physics itself. Neither Einstein nor Newton, presumably, would dispute that part of the purpose of physics is to account for the movement of planetary bodies, and that any theoretical innovation that allowed for a better account of this movement, without sacrificing (indeed, in Einstein’s case improving) explanatory power in other areas, would constitute an advance.

Second, paradigms in physics are directed towards a physical reality that, in the long run at least, serves as an arbiter that rewards good theories and punishes faulty theories. Political philosophy works rather differently. How to best conceptualize “space” and “time” will have to be worked out through combining reasoning and experimentation, but there is no scientific experiment that can be run to decide on the best conceptualization of “freedom.” When it comes to conceptual disagreements in political philosophy, reason has to carry the burden on its own. Thus, any progressive development in political philosophy will primarily be an internal movement in reason itself. The dialectical expression of this would be that the relation between a higher and a lower level of understanding in political philosophy is such that the higher-level position understands—not some external reality—but the lower-level position better than the lower-level position understands itself (Skjervheim 1996, 274).

That it is possible to gain understanding in political philosophy such that one might conceivably at some point in a larger process of intellectual maturation look back at previous positions one used to hold as inadequate in comparison to the position one now holds, is, I would think, uncontroversial. The first complication, then, seems more urgent to address. Do we have a (or several) dialectical yardstick(s) of progress in political philosophy as we arguably have in physics? Do we have a set of criteria rooted not in a particular political–philosophical position, but in the very purpose of political philosophy itself, that might serve as a common standard for this practice? Perhaps we do.

I began this essay by connecting political philosophy to the idea of political legitimacy. The purpose of political philosophy, I claimed, is to establish the contours of the politically legitimate: what can be justified as just, fair, reasonable, and right when it comes to political institutions and practices. Even if particular ideas about what is just, fair, reasonable, and right are likely to be contested, it is difficult to contest the very ambition of justifying political institutions and practices in the first place. Indeed, I would like to entertain the notion that abandoning this ambition in political philosophy is like abandoning the ambition of explaining physical phenomenon in physics—it would mean, in effect, abandoning the practice itself.

Everyone who argues from and for a political–philosophical position—be it liberalism, Marxism, Islamism, or any other “ism”—has, regardless of any other disagreements they might have, implicitly or explicitly agreed that political institutions and practices should be justified; that these institutions and practices should be backed by argument and not simply by force. Even the most hard-nosed political realists who believe the Hobbesian dictum that “before the names of Just, and Unjust can have place, there must be some coercive Power” (Hobbes 2012, 66) cannot completely escape justification. They too feel the need to argue the supposed futility of political argument and its surrender to power, which then turns into an (implicit) justification of any political order as long as it is powerful enough.

This commitment to justification, then, can form a criterion of internal coherence of a political–philosophical position: does the position accommodate the demands that justification, and therefore political philosophy itself, places upon us? The specification of these demands and the answer to this question will be crucial components of this justificatory strategy in practice.

One way to cash this out is to consider the implicit assumption about human nature involved in the claim that political institutions and practices should not merely exist, but also be justified. This is actually, I would contend, a very specific claim about human liberty. First, it is a claim that institutions and practices are, in some form, under our collective control; that the laws, rules, and norms that govern these institutions and practices are social constructs that can sensibly be critiqued and not immutable natural laws (which, of course, cannot be sensibly critiqued in the same way). Second, it is a claim that that such critique is possible; that the individual human being in some way is ontologically detached from his [their] political (and social) surroundings in such a way that he or she is [they are] capable of taking a critical stance towards those surroundings. In short:

The practice of political philosophy is built a liberal concept of human freedom as a private sphere for reflection of self-definition—which is the basis for, among other things, adopting an autonomous stance on political arrangements. Only against this background understanding of human freedom does the practice of philosophy and the BLD become sensical.

If the above claim is true, then non-liberal political philosophy, that is, political philosophy that does not put the individual’s autonomy at its core, is not only anti-liberal but anti-philosophy. Or to put it another way: non-liberal political philosophy is, in the last instance, incompatible with political philosophy itself. As such, Marx’ admonition to stop philosophizing and start acting—to stop interpreting the world and start changing it—is a perfectly coherent part of his attack on the bourgeois–liberal state. In a liberal state, philosophy, insofar as it is aware of its own conditions of possibility at least, is a conservative force. Abolishing liberalism means abolishing philosophy (or at least curtailing it), as indeed totalitarian states usually do—sometimes, perversely, in the name of “freedom.”

Of course, the liberal concept of freedom could be accepted as a condition for political philosophy and yet devalued in particular political–philosophical positions. Human liberty (in the liberal sense) could be recognized as real, but not worthy of political protection and nourishment. Would this make the particular political–philosophical position theoretically incoherent? Perhaps not, but I would argue that maintaining such a position would make the practice of political philosophizing incoherent, in the sense that it would undermine its own foundation. To politically argue against the conditions of possibility of political argument is to rebel against the project of political philosophy no less than to abandon the quest for explaining physical phenomena is to rebel against the project of physics.