Pascal's Wager, Bayes, and Protestantism

John Vandivier

In this article, I add a new argument that reinforces a preference for Protestantism on the basis of Pascal's Wager, or more generally on the basis of probabilistic and utilitarian analysis.

In the past, I have argued that Pascal's Wager supports Christianity and in particular those denomination(s) that profess Salvation by Faith Alone (aka Sola Fide) and Eternal Security. This article would provide a second layer of reasoning for a candidate Christian to prefer Protestantism over Roman Catholic or Eastern Orthodox denominational belief.

I. Protestantism Demands Less

Protestantism is diverse enough that there are vanishingly few doctrines - perhaps no doctrines - that are universally considered to be essential. This is a sword that cuts both ways and some consideration to the downside of this is considered in the subsequent section. On the positive side, there are at least four ways that minimal doctrinal requirements make Protestantism comparatively attractive:

  1. Any denomination which adds works as a requirement of salvation comparatively weakens the cost-benefit analysis. This is an insight from Pascalian analysis.
  2. The evidence required to prove the prior probability of a belief set is lower when the belief set is smaller, less specific, and less complex. This is an insight from Bayesian analysis.
  3. The odds of encountering a repulsive doctrine are smaller when the total number of doctrines are smaller. It's straightforward to construct an economic model where individuals with heterogenous preferences would be more likely and willing to accept a religion of few repulsive doctrines.
  4. The cognitive load and intellectual price tag of a religion with few essential beliefs is lower, and thereby appealing.

This article emphasizes the importance of point 2 above and for further context I point you to the recent discussion between Cameron Bertuzzi and Suan Sonna:

https://www.youtube.com/watch?v=DT0-Or2k6r0

I also echo Cameron's point that a Bayesian interpretation of \"extraordinary claims require extraordinary evidence\" is not only non-threatening to the Protestant but is actually an advantage of the Protestant to the atheist when one considers the power of cumulative evidence in an analysis using Bayes' Theorem. That is an aside from the present inner-denominational conversation.

II. Maximizing Value of Doctrine

If minimizing beliefs is optimal, why not reduce beliefs to nothing and accept agnosticism or atheism? The obvious point is that we want the benefits of eternal salvation. Why not just invent a variant of Christianity where we get all of these benefits with minimal commitment? The answer is that we need an interpretation of Christianity that is actually true.

Not only do we want to realize eternal salvation, but we also want to realize value from the truth. Knowing true things is valuable. Therefore, an optimal approach is not simply to maximize prior probability by minimizing the scope of belief. Instead, we want to optimize such that marginal cost equals marginal benefit with respect to doctrines affirmed and after weighting for prior probability on a per-doctrine basis.

This optimization should occur at the doctrinal level, and denominations can be seen as collections of doctrines. Yet, both Roman Catholicism and Eastern Orthodoxy fall to the \"accept all official doctrines or get out\" according to some. This is a further point in favor of Protestantism.