You’ve probably met people in your life who you disagree with so much that, not only is it unclear whether the disagreement would ever be resolved, but it’s far from obvious that you’re communicating at all. You might have given arguments or presented evidence for your belief, but the other person questions the basic presuppositions of your arguments. They doubt that your so-called “evidence” is really evidence.
If this has happened to you, you were probably the participant of what philosophers call a “deep disagreement”.
Deep disagreements aren’t like ordinary disagreements. Typically, ordinary disagreements have rational resolutions. Imagine you and a friend want to split the tip after dinner, and you both mentally calculate what the tip should be before you’re given the bill. We can assume that you both agree on what percentage the tip should be. However, you come up with different answers on the amount: you say it’s £6, while your friend says £4 is correct. You disagree with one another. Intuitively, not only can you easily resolve this disagreement, you can do so rationally: you can just get the bill and run the calculations again (perhaps this time with a calculator). Typically, you’ll converge on the right answer. Your dispute will be rationally resolved.
Deep disagreements don’t seem to work this way. For example, consider the Young Earth Creationist and the Modern Scientist. They disagree about the age of the Earth – but not only that. They seem to have a clash of competing world-views in addition to their clash over the age of the Earth.
Although it’s not obvious how we should define deep disagreement, there are plausible markers of them. The first is the ripple-effect: one disagreement is proxy for many other, potential disagreements. For instance, the disagreement between the Young Earth Creationist and the Modern Scientist extends not only to the age of the Earth, but also to the origin of the Earth and the origin of human beings, among other things.
The second is the fundamentality of the disagreement. When the Young Earth Creationist and the Modern Scientist disagree over the age of the Earth, they quickly discover that they disagree over general epistemic principles as well, such as whether scientific testimony and the institutions that foster scientific research are trustworthy; or whether carbon-dating is a reliable method; and so on.
These two features alone might make you worried that deep disagreements aren’t practically resolvable. How could the Young Earth Creationist and the Modern Scientist resolve their disagreement about the age of the Earth without examining all the other interrelated issues they disagree about? Time constraints might limit what is resolvable. And even if they could do this, why think that any one of them would change the other’s mind? As we have learned from modern psychology, in the face of deep conflict, people tend to stick to their guns.
Ludwig Wittgenstein spent his final years thinking about the nature of knowledge, scepticism, and the structure of belief systems. His thoughts were posthumously published in 1969 as On Certainty. He thought that the activity of doubting and believing generally presupposes a background of unargued “certainties” which are “beyond being justified and unjustified”. The role of these certainties in a belief system is that they enable certain things to be grounds for belief or doubt generally, and as such are themselves groundless. These certainties are what Wittgenstein called the “hinges”, or hinge commitments, on which our beliefs about the world turn.
In order to apply Wittgenstein’s idea about hinge commitments to deep disagreement, consider the Young Earth Creationist again. On the Wittgensteinian view, the proposition that the Bible is the most reliable basis for forming general beliefs about humankind and the cosmos is a hinge commitment of the Young Earth Creationist’s belief system. For the scientifically-informed person, however, it isn’t. Their disagreement is “deep” precisely because there is a clash between these two commitments, marked by their clash over the age of the Earth. When the Young Earth Creationist questions the modern scientific view that the Earth is billions of years old, they question the entire world-view which makes sense of it (and vice-versa).
The Wittgensteinian view of deep disagreements has two parts. The first part is that deep disagreements are clashes between our different hinge commitments, the commitments that frame the basic structure of our belief systems. The second part is that hinge commitments as such are neither reasonably believed nor reasonably doubted. For they are what makes reasonable belief and doubt possible in the first place, and thus they aren’t subject to rational evaluation. From these premises, two conclusions seem to follow. First, that disagreements over hinge commitments aren’t rationally resolvable. And, secondly, since deep disagreements just are disagreements over hinge commitments, it follows that deep disagreements aren’t rationally resolvable either.
As can be expected, philosophers diverge over what the basic nature of hinge commitments are supposed to be. As noted, they all agree that hinges play a fundamental role in framing our picture(s) of the world. They just disagree about what they are at a certain level of detail. The so-called “non-epistemic” theorists think that hinge commitments aren’t in the market for being reasonably believed or doubted by any means. One reason they think this is that the hinges aren’t capable of being true or false, since they’re more like non-factual rules. Against them, the “epistemic” theorists think that the hinge commitments are capable of being true or false, and at least potentially reasonably believed, albeit in a way which is different from ordinary belief.
Now, there’s a straightforward route from the non-epistemic theory of hinges to the impossibility of disagreement over them. For disagreement concerns what one can be right or wrong about. But if you can’t be right or wrong about the hinges which frame your picture of the world, then you can’t even disagree about them. And if you can’t even disagree about whether any of them are right, then surely you can’t rationally resolve a disagreement over them either, for there can’t be any such disagreement!
The epistemic theory is more promising in this regard. Proponents of this theory think that the hinges are capable of being true or false. So, you could in principle disagree over which are the right ones to hold. The problem is that hinge commitments are weird. Some epistemic theorists think that while the hinges can be true or false, nevertheless, you can’t get any good evidence for them. As such, believing any of them would be irrational. At best, you can only trust that they are correct, in a way that is closer to faith than belief. And whether rational trust or faith is even possible is an open-question. It might make you feel better, and, practically speaking, you might do better by believing it, but this doesn’t mean that it’s rational.
Some other epistemic theorists think that it’s a purely contextual matter whether you can have good evidence for your hinge certainties. On their view, the Fundamentalist “Flat-Earther” can genuinely rationally believe that the Earth is a flat disc, created no more than 6,000 years ago by God. And a contemporary scientifically-informed person can rationally deny all of that. Here’s the caveat: such beliefs are rational only within a context of inquiry: a context where you are presupposing certain things and bracketing them for the purposes of your intellectual goals. What gets presupposed in such contexts are the hinge commitments of that context. They’re what you need to get going with that inquiry.
With respect to rationally resolving deep disagreements, there’s two sorts of problems for this view. The first problem is that both the Fundamentalist and the scientifically-informed person come out as equally rational – at least, relative to different contexts. So, there’s really nothing to settle between them, as both are rational. The second problem is a bit more complicated. Recall the Wittgensteinian view that deep disagreements are disagreements over which hinge commitments are correct. Now consider something like “God is the creator of all life on Earth”. The thought is that such a proposition is a hinge in some contexts but not others. In the Christian’s contexts, it is. In the Taoist’s contexts, it isn’t. The problem is that, in a context where that proposition has the status as a hinge commitment, it would follow that questioning, doubting, or disputing it would change the context: for we would shift its status from a hinge to something else. So, when we do debate it, it’s not really a deep disagreement anymore on the Wittgensteinian view, as it would lose its status as a hinge.
Wittgenstein himself was sceptical not only of the rational resolvability of deep disagreement, but even the very possibility of deep disagreement. He thought that genuine deep disagreement would look alien to us. We would lose our grip on what counted as evidence, rationality, or reasons (see §231). Given such a loss, we wouldn’t know how to proceed. In particular, he thought that there would be some sort of communicative failure between the disagreeing parties. It would be a kind of verbal disagreement. For example, on this sort of picture, although the Young Earth Creationist and the Modern Scientist might be speaking words they each seem to understand, they would be speaking a different language. “Doubt”, “belief”, “evidence”, and so forth, would mean something different in each of their mouths. Taken like this, deep disagreement as such wouldn’t be possible.
In short, we’ve seen that if the Wittgensteinan view of deep disagree is correct, rationally resolving disagreements are also impossible. While this view raises many complex epistemological questions, I think it raises an important moral question as well.
The moral challenge is that, if we can’t rationally resolve our deep disagreements, one might be tempted into thinking that this justifies pursuing other, questionable means of resolving such disputes (such as through manipulation, propaganda, brainwashing, coercive persuasion, or even violence). The thought here is that when rational means cannot help us, only irrational means are left.
Indeed, Wittgenstein was aware of this sort of problem. He said that “at the end of reasons comes persuasion”, adding: “Think what happens when missionaries convert natives” (§612).
One is liable to think that the moral problem is really no problem at all. For violence, manipulation, brainwashing, or other coercive and morally questionable means of resolution are all morally unjustified. So, obviously participants of a deep disagreement would be unjustified in using such methods. This sort of reply is right so far as it goes … but it misses the point. The moral problem of deep disagreement implies a practical problem: what should people do, all things considered, to resolve a deep disagreement if there simply are no rational ways of resolving it? Suppose that appealing to morally questionable methods of resolution are all unjustified. So, manipulation, coercion, brainwashing, etc., are all out of the picture. We would still be left with persistent deep disagreement. What do we do? If the rational ways are unworkable, and we are of course justifiably unwilling to take the immoral path, we need to start thinking of new ways to help us resolve deep disagreement. Wittgenstein seemed pessimistic about the prospects of this – as many of us might be.
But perhaps a Wittgensteinian method is appropriate here too. Once we diagnose the source of a deep conflict, we can aim for a therapeutic resolution. This might involve educational institutions taking seriously the idea of training people to think clearly, openly, cautiously, respectfully, and rigorously, cultivating intellectual virtue, and learning to avoid habits which lead to vices. For it’s not so clear that the intellectually virtuous person would engage in persistent deep disagreement, since their beliefs might not be anchored as heavily as our own, owing to their intellectual character traits and habits. Education, self-understanding, open-mindedness, tolerance, and humility would be a way of mitigating the potential negative effects of deep disagreement.
The general line of thought here is therapeutic. If the Wittgensteinian view of deep disagreement is correct, we need to face the practical moral problem that it raises. Contemporary liberal democracies tend to value cultural and religious pluralism, and a dynamic open-society. These virtues bring with them the potential for deep disagreement. At an individual level, deep disagreement forces us to inquire into the hinge commitments of our own belief systems, not just other’s. We can also inquire into the role that our intellectual character traits and habits might play in our confrontations with people who deeply disagree with us. More optimistically, we can expect that these types of inquiries would have lasting positive effects on the society at large. For we would be less liable to stick to our guns and find fault with the other because we are also turning our attention inwards towards ourselves. The idea here is that intellectual virtue will help the participants of deep disagreement navigate the thorny moral and practical path that such disagreements create. Of course, this isn’t a solution to the moral problem raised by deep disagreement. But, in any case, it’s not so evident that we should even be looking for solutions. Like the ancient Hellenistic philosophers, a better route might be to follow a broadly medical methodology: diagnose the sources of our deep disagreements; try to understand how and why they grew; find ways to mitigate any potential negative effects of them; and find appropriate ethical ways to prevent them in the future.
Finally, it should be noted that the moral problem is specifically a problem for the Wittgensteinian view of deep disagreement. As I argued, the Wittgensteinian view seems to have the consequence that deep disagreements aren’t rationally resolvable, and this fact is what raises the moral problem. If we think the moral problem is far too intractable or counter-intuitive, this should make us look more closely at the Wittgensteinian view, and whether it’s the right way of understanding deep disagreement.