Conciliatory Views on Peer Disagreement and the Order of Evidence Acquisition

Marc Andree Weber

doi:10.1515/krt-2021-0023

Abstract

Abstract The evidence that we get from peer disagreement is especially problematic from a Bayesian point of view since the belief revision caused by a piece of such evidence cannot be modelled along the lines of Bayesian conditionalisation. This paper explains how exactly this problem arises, what features of peer disagreements are responsible for it, and what lessons should be drawn for both the analysis of peer disagreements and Bayesian conditionalisation as a model of evidence acquisition. In particular, it is pointed out that the same characteristic of evidence from disagreement that explains the problems with Bayesian conditionalisation also suggests an interpretation of suspension of belief in terms of imprecise probabilities.

Highlights

Let us assume that Richard’s credence towards the proposition that Pete will drink more than three beers tonight is 41, while Siena’s credence towards the same proposition is 43
The evidence that we get from peer disagreement is especially problematic from a Bayesian point of view since the belief revision caused by a piece of such evidence cannot be modelled along the lines of Bayesian conditionalisation
This paper explains how exactly this problem arises, what features of peer disagreements are responsible for it, and what lessons should be drawn for both the analysis of peer disagreements and Bayesian conditionalisation as a model of evidence acquisition

Summary

Introduction

Let us assume that Richard’s credence towards the proposition that Pete will drink more than three beers tonight is 41, while Siena’s credence towards the same proposition is 43. Richard and Siena know Pete’s drinking behaviour well, and they know from past experience that they are good at predicting how many beers he will have. Richard and Siena are epistemic peers concerning Pete’s drinking behaviour: they are competent and knowledgeable with regard to predicting it.. Conciliatory views are often said to apply, when it comes to predicting specific aspects of human behaviour, and in those peer disagreement cases in which we seem unable to find out who is right. In order to tackle these issues, using credence talk is helpful but inessential It is helpful insofar as it simplifies the presentation a lot; it is inessential insofar as all that follows could be reformulated in terms of just three doxastic attitudes – belief, disbelief, and suspension of belief – instead of continuum many.

Splitting the Difference and Bayesian Conditionalisation

The Optimal Order of Evidence Acquisition

Disagreement-Induced Suspension of Belief and Imprecise Probabilities

Conclusion