UCSB Philosopher Examines Reasonable Disagreement and Political Policy

Christopher McMahon, a professor of philosophy at UC Santa Barbara, has a new take on disagreements –– particularly those that are political in nature. His most recent scholarly work could lead to a greater acceptance of differing points of view, or, at the very least, offer an explanation about why even the most well- reasoned arguments generally fail to bring everyone into agreement.

In his new book, "Reasonable Disagreement: A Theory of Political Morality" (Cambridge University Press, 2009), McMahon examines the ways in which reasonable people can disagree about the requirements of political morality. He argues that a "zone of reasonable disagreement" –– a range of possible positions that can be taken –– surrounds most questions of political morality, and that the zone evolves over time, so what might have been reasonable hundreds of years ago is not so today.

"There is an idea in political philosophy today that under ideal conditions people deliberating in good faith will reach a consensus about political policies that should be adopted," McMahon explained. "Central to that idea is the notion that when people argue opposite sides of an issue, someone is making a mistake, and through deliberation those mistakes can be identified and corrected. And if everyone's reasoning is correct, then consensus can be reached.

"My suggestion is that even after deliberation, and all mistakes in reasoning have been eliminated, people are still going to disagree," McMahon continued. "Deliberation makes people competent reasoners, but competent reasoning doesn't produce agreement." The fact that every political issue has a range of reasonable positions makes consensus virtually impossible. This does not mean that the people are reasonable all the time. "If you listen to political opinion in the United States, not everything you hear is an example of reasonable disagreement. A lot of it is, in fact, unreasonable," McMahon added.

McMahon's book also puts reasonable disagreement in historical perspective. Positions that could be reasonably held in the past, such as the endorsement of political hierarchy, can become unreasonable. "But when an issue –– such as the merits of capitalism versus socialism –– have been openly debated over an extended period of time with no resolution, there's good reason to believe that the people taking each position are reasoning competently," he said

Although a disagreement can be reasonable, it can also be marked by controversy because, according to McMahon, participants do not recognize arguments contrary to their own as reasonable, no matter how well-framed they may be. "People can agree to disagree in the sense that they realize they are not going to come to an agreement, but that doesn't mean either one thinks the other is reasoning well," he said. "I think we can understand more of what goes on in politics as reasonable disagreement if we realize that opposing positions aren't necessarily recognized as reasonable."

Given that political cooperation requires agreement, but that complete consensus is virtually impossible, some mechanism is necessary to determine which courses of action will be taken. "From that standpoint, democracy seems like a reasonable way of resolving political disagreements," McMahon said. "It's a fair way of deciding which policies are going to be enacted. It's not the only way, but it's a reasonable one."

Related Links

Cambridge University Press

Share this article