In order to break the trend of announcements I’ll venture a comment on Adam Elga’s recent Nous paper “Reflection and Disagreement”. Elga argues for the equal weight view which, as a first pass, states that you should assign the conclusions of your epistemic peer the same weight you assign your own conclusions. I was surprised, though, that Elga characterizes an epistemic peer this way:
My use of the term “epistemic peer” is nonstandard. On my usage, you count your friend as an epistemic peer with respect to an about-to-be-judged claim if and only if you think that, conditional the two of you disagreeing about the claim, the two of you are equally likely to be mistaken (p. 499, endnote 21).
On this characterization the equal weight view seems to be a trivial consequence of thinking someone is my epistemic peer. The standard usage invokes the idea of general intellectual virtues, e.g., thoughtfulness, honesty, intelligence, freedom from bias, etc. Given the standard view it seems obvious that the equal weight view is false. My colleagues in the math department are my epistemic peers but if I disagree with them on some theorem in topology I should go with their judgment. A more relevant sense of an epistemic peer will invoke intellectual virtues and broadly evidential considerations. On this characterization your epistemic peer has roughly the same evidence that you possess vis-a-vis a target proposition and is roughly just as competent as you in evaluating the evidence. This view of epistemic peers doesn’t seem to trivialize the debate in either direction.
Here’s another consideration in favor of a more general notion of epistemic peer. It strikes me that no one would think it right to favor the result of one metal detector over another equally good metal detector when the circumstances were the same and they disagreed. So, to the extent you view another person and yourself as equally good truth-detectors in some domain and yet you disagree, it seems you should assign equal weight to each other’s conclusions.