Spring 2018 Colloquium Series - 9 March
Kenny Easwaran, Texas A & M :: Diachronic and Interpersonal Coherence
(joint work with Reuben Stern, Munich Center for Mathematical Philosophy)
Friday, March 9 2018
Much recent work in formal epistemology aims to justify requirements of diachronic coherence, stating that a person's current beliefs and future beliefs rationally ought to be closely related to each other, with differences attributed to gains in evidence over time. David Christensen challenges these arguments by showing that formally similar arguments would lead to an argument that people that share a bank account rationally ought to have exactly the same beliefs as each other. However, following Donald Gillies, we embrace this analogy and suggest that both interpersonal and diachronic coherence requirements exist, but only to the degree that interests are shared, and behavior can be coordinated.
From this idea we develop a picture of social epistemology in which each person is a member of multiple overlapping groups, so that competing coherence requirements can't all be satisfied. Furthermore, we consider various arguments suggesting a positive value for diversity of opinion in groups. Finally, we draw the parallel to successive states of the same person, and suggest that the standard coherence arguments have less force than thought. Successive states don't share all their interests, can't always coordinate their behaviors, and are often parts of incompatible social groups. Moreover, even when interests are aligned, there are purely internal reasons for some stages to disagree with others in order to achieve the benefits of cognitive diversity.