April 25, 2017

The Why and How of Reasonable Disagreement



Free societies are rife with disagreement about matters of ultimate importance—religious, moral, economic, and political. That’s a consequence of the free exercise of human reason, which is necessarily limited by cognitive and environmental factors. We must somehow accommodate these disagreements if we are to remain free.

Among the most important ways we do so is by figuring out when our disagreements are reasonable. A free society should tolerate and draw strength from reasonable disagreements, even if it dismisses unreasonable ones.

This essay explores the idea of reasonable disagreement and explains how to determine whether you’re having one or not.

Reasonable Disagreement and the Burdens of Judgment

Sometimes people on both sides of a disagreement are adequately informed, reflective, sincere, and bear one another no ill will. A reasonable disagreement is one that would persist even among such persons.

John Rawls held that reasonable disagreements exist due to six features of human psychology, reason, and institutions that he called the “burdens of judgment.” In disagreeing on many issues,

  1. The evidence bearing on the disagreement is conflicting and complex.
  2. Even when we agree on the relevant considerations, we may disagree about their weight.
  3. Our concepts, not merely moral and political concepts, are often vague and vulnerable to being undermined by hard cases.
  4. The way we assess evidence and weigh values is shaped by the unique, total experience that each of us brings to the table.
  5. We often find different kinds of normative considerations on both sides of an issue, making an overall assessment difficult.
  6. Any system of social institutions is limited in the values that it can attempt to defend or further. And many hard decisions may have no easy answer.

Religious, moral, and political disagreements obviously involve complex reasoning and evidence. It seems plain enough that people can look at the same evidence and come to different conclusions. The same is true when weighing different arguments and other considerations. Anyone who has taken an introductory ethics course knows that our moral concepts are vague and subject to hard cases; likewise our political concepts. Most people will admit, when pressed, that their beliefs are based on their unique life experiences. Reflecting on this fact could help people see that diverse others might have good reason for believing and acting as they do.

F.A. Hayek offers an account of the sources of disagreement that is similar to Rawls’s, but is in some ways much richer. Hayek argued as early as 1944 that disagreement about the relative weight of moral values will lead to evaluative pluralism; even the “scales of value” of rational, moral people “are inevitably different and often inconsistent with each other.” Later on, Hayek developed an even more radical account of the burdens of judgment. He understood the mind as a system of rules that organize subjective perceptions in cognitively unique ways. The mind itself is “a particular order of a set of events taking place in some organism and in some manner related to, but not identical with, the physical order of events in the environment.” The result is that different minds will map the world differently, for their knowledge of the world is inevitably subjective, limited, and distinct from the knowledge of others.

For Hayek, each person only possesses a tiny, distinct piece of knowledge about how to create a functioning social order. I think we can conclude from this that our reasons to accept the rules that comprise that order will, consequently, be radically situated and subjective.

The Rawlsian and Hayekian burdens of judgment suggest that disagreements about matters of ultimate import are frequently non-culpable. People who reason well with respect to their evidence can come to dramatically different conclusions about not merely political and policy issues, but about which forms of life have ultimate value. Given their unique life histories, people are rationally entitled to affirm quite different views about complex issues. We can reasonably disagree about many matters, including a vast number of political issues and their underlying normative and empirical suppositions.

The burdens of judgment also imply that we’re going to have trouble recognizing a reasonable disagreement even when there is one. Since our perspectives are so limited and different, we will have trouble understanding how others can disagree with us. The same contestable, ambiguous facts that should lead us to recognize reasonable disagreements can prevents us from seeing that they are reasonable in the first place.

Some Examples of Reasonable and Unreasonable Disagreements

Reasonable disagreements come in two broad varieties – normative and empirical. A reasonable normative disagreement concerns the identification and application of moral principles and values. Two parties might disagree, for instance, about the relative importance of deservingness in determining when redistribution is justified. Some people think that “the undeserving” should not receive social insurance, whereas others are more inclined to discount desert and pay more attention to need. A reasonable empirical disagreement, by contrast, might concern whether some law or policy will have the effect its proponents predict.

An important example of reasonable normative disagreement concerns the morality and legality of abortion. Pro-lifers and pro-choicers do disagree not merely about when a fetus becomes a person. They also disagree about whether bodily autonomy or preserving the life of the child is more morally important. Pro-lifers say that the life of the child outweighs bodily autonomy, whereas pro-choicers say that bodily autonomy is paramount. Unless we deny that one of these considerations is at all important, we will have to agree that there are arguments on both sides, and that the proper balance between the two considerations is unlikely to be obvious to any informed and reflective person of good will. Are any of us really in a cognitive position to make that determination, and so to justify our temptation to think that those who disagree with us have made a culpable mistake?

An important example of reasonable empirical disagreement concerns the effects of social insurance on poverty and economic growth. Some economic models suggest that redistribution will strongly disincentivize economic growth and create bad incentives for the poor, whereas other economic models suggest that the disincentive effects on growth are small and that the poor tend to make good choices with the transfer payments they receive. These are complex issues based on incomplete data. And it isn’t hard to see how people could survey various models, choose one that seems plausible, and come to their own conclusions.

The same is true of disagreements about appropriate countercyclical policy. It is very hard to know why we have business cycles, much less how to reduce their severity.

Unreasonable disagreements are common, to be sure. One unreasonable normative disagreement would be the rejection of the moral equality between races. Someone who forthrightly affirms that whites are more morally important than blacks probably cannot hold her position with adequate reflection and honesty, and certainly not with good will. We can imagine someone from a previous period in human history who thought as much, but today holding such a belief cannot survive adequate rational scrutiny, nor is the belief compatible with having a decent moral character.

Unreasonable empirical disagreements are even more common, such as advancing policies and candidates based on conspiracy theories, or the position that vaccines cause autism. No adequately informed and reflective person can stably believe that vaccines cause autism when confronted with the evidence.

Recognizing Reasonable Disagreements in Three Steps

As I’ve noted, recognizing reasonable disagreements is hard due to our cognitive biases and our limited means of determining why others advocate the positions that they do. Consequently, our tendency is to believe that our political opponents hold the positions they do because of some culpable failure on their part – a failure of reflectiveness or information collection, or a fundamental insensitivity to a fundamental moral imperative or value. But our cognitive limitations and biases will lead us to overestimate the frequency of unreasonable disagreements, so we should resist the temptation to condemn others for disagreeing with us.

I’d like to end by explaining how one might go about trying to recognize a reasonable disagreement when one presents itself. Imagine that you find yourself in a moral or political disagreement with another person and you are inclined to regard the disagreement as unreasonable (on their part). Here are three useful facts to reflect upon.

  1. First, your cognitive limitations are great, and this probably affects your judgment that others have made a culpable error in defending their position, or your judgment that they would no longer hold their position if they thought about the matter carefully. In general, it is really hard to know why people think what they think. So begin simply by pausing and reflecting upon your biases and limitations, and how they could hamper your judgment.
  2. Ask yourself whether you have enough information and have engaged in enough reflection about the mental state of your interlocutor to be rationally entitled to believe that they cannot affirm their position with good will after adequate reflection. That is, try to determine whether your disagreement would persist were your interlocutor reasonable. If you cannot easily make this determination, apply a principle of charity: assume that the disagreement is due to non-culpable factors.
  3. After applying the principle of charity, act on it. Honestly and respectfully try to determine, in conversation, whether the other person has good information and arguments for her position and whether she is prepared to take your positions and arguments seriously. If your interlocutor appears to have flawed information or uses clearly fallacious arguments, then that is an adequate basis for determining that the disagreement would not persist among reasonable people and that the other person’s position can be reasonably dismissed.

I suspect that if people followed this procedure during their moral, religious, and political disagreements on social media, where it is especially hard to tell why people affirm what they affirm (given how little one knows about them), we would find that we dramatically underestimate the frequency of reasonable disagreements. But what is true online is true in most political conflict. Each of us is in her own bubble of experience and information, as are those with whom we disagree. Unless we break through these cognitive barriers, it is difficult, at best, to understand our opponents’ point of view. Yet the first thing we seem inclined to do is contemptuously impugn their motives, their rationality, or their intelligence. This is dangerous and unwarranted.


Kevin Vallier is Associate Professor of Philosophy at Bowling Green State University, a Niskanen Center adjunct fellow, and author of Liberal Politics and Public Faith: Beyond Separation.