William & Mary

W&M philosophy professor, fellow tackle reasons and rationality

  • Felipe Medeiros (left) and Chris Tucker sitting in chairs
    Discussing reasoning:  Graduate student on fellowship Felipe Medeiros (left) has frequent and protracted discussions with William & Mary Associate Professor of Philosophy Chris Tucker about how the two see ideas about reasoning, and how to present their very disparate views.  Photo by Jennifer L. Williams
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Chris Tucker is spending his research leave for 2019-20 looking at how people weigh reasons when making decisions, and how they might do it more effectively.

Tucker, associate professor of philosophy at William & Mary, is getting additional fodder for that effort by advising a graduate student on fellowship doing similar work. Felipe Medeiros, a doctoral student from the Pontifical Catholic University of Rio Grande do Sul in Brazil, is spending the year at W&M on a fellowship from the University of Houston’s LATAM Bridges project. The project seeks to create connections between Latin American and North American philosophers working in the epistemology of religion.

Tucker is working on several papers, and Medeiros will write two papers over the course of the year. Their projects dovetail, provoking plenty of room for discussion.

“His general project is focused on the case of disagreement and how to deal with the reasons that emerge from that case,” Tucker said. “Whereas my project is sort of more abstract about the general concept of weighing reasons and trying to provide a model that gets weighing reasons right.”

A single-scale model of weighing reasons — think scales of justice — is an intuitive starting point, Tucker acknowledges. Examples of single-scale model include getting a job offer with a better salary but in a less desirable location.

Taking the job depends on the relative weight of the reasons for and against, according to Tucker. If the salary is weighty enough, it might be worth dealing with the less desirable city. Or if the city is really undesirable, it might override the salary.

Another scenario considers weighing a study that finds that coffee increases high blood pressure and another that finds the opposite. What should the person believe? It seems to depend on the weight of the reasons for and against believing that there’s this link, Tucker said.

“It seems like when we’re dealing with what we should believe, and with what we should do, those things are determined by two factors — how we weigh reasons against one another to determine what we should do and what the weights of those reasons are,” Tucker said. “So my project is on the general idea of weighing reasons. What is the right way to think about weighing one reason against another?”

Medeiros is interested in the phenomenon of disagreement, particularly religious disagreement, and what sort of cognitive attitudes one should have when faced with the fact that other reasonable people do not share the same beliefs.

“On what sort of circumstances do you have to revise your beliefs?” Medeiros said. “On what sort of circumstances can you hold on to them? Can we give a theory that captures those features? Those are the basic questions that drive a lot of the investigation.”

For example, two people who know each other well and trust one another disagree when discussing a political issue. The fact that another reliable person disagrees is a reason against each person’s point of view.  Medeiros argues that such reasons often don’t matter and can be reasonably dismissed.

“So it’s the idea that once you know something, the counter-evidence that people think you’re going to get could be disregarded because if you know it then any evidence against it is going to be misleading,” Medeiros said. “And how that makes it so that the rules for revising your beliefs are different than one would expect at first.”

The two philosophers come from very different approaches, he added. Medeiros is an externalist who thinks that reasonability is influenced by outside factors such as other people, the environment and surrounding world.  Tucker is an internalist surmising that reasonability solely is influenced by what’s internal to your mind, such as your beliefs about other people, the environment and surrounding world.  Their projects are only tangentially related, but each is helping the other with how their arguments should be presented.

Tucker is trying to give the exact model for how reasons are to be weighed, he said. The single scale model assumes that there is only one kind of reason, which he contends “is very hard to reconcile with a lot of intuitive thinking about what we should do or not do.”

For example, the assumption doesn’t fit very well with how one thinks about supererogation, which is going above and beyond the call of moral duty — say, the idea of a solder jumping on an enemy grenade to sacrifice his or her life to save several fellow soldiers.

“Morality forces you to take others’ interests into account,” Tucker said. “These people’s lives are at stake. You have to give their lives weight. But a standard assumption is that, morally speaking, you don’t have to give your own life weight … So, if we can go beyond the call of moral duty, then we have two different kinds of reasons that must be weighed.

“We have reasons that are requiring reasons, reasons that count in favor of an action only insofar as they count against the alternatives — altruistic reasons. And we have some kinds of reasons that seem merely justifying — self-interested reasons, reasons that push an action like remaining in safety towards permissibility without making it a mistake to do the alternative.”

It is the latter kind of reason that a single scale can’t accommodate.  For, on a single scale, as the reasons weigh toward doing something, they weigh against not doing it.

He argues that two scales, not one, are needed to correctly represent different kinds of reasons. Such a dual scale model allows for the possibility that self-interested reasons count in favor of remaining in safety without thereby counting against the morally better sacrifice.