The Muslim Time’s Chief Editor’s comment: By the Grace of Allah, I joined Ahmadiyya Muslim Community, from a Sunni family, in 1984, while I was in my Medical School. Since then I have engaged Sunni Muslims in debate and for the last few years, I have had opportunity to tackle Christian apologists, in different discussion forums and the Muslim Times itself and the following thoughtful article, beautifully summarizes my 30 year experience.

Disagreement, Dogmatism, and Belief Polarization

The human mind gets creased into a way of seeing things.   –Antoine Lavoisier, Reflections on Phlogiston

I. Introduction

Consider the phenomenon of belief polarization. Suppose that two individuals—let’s call them ‘You’ and ‘I’–disagree about some non-straightforward matter of fact: say, about whether capital punishment tends to have a deterrent effect on the commission of murder. Although neither of us is certain of his or her view, I believe that capital punishment is a deterrent while You believe that it is not. Perhaps one or both of us has evidence for his or her view. Or perhaps we hold our views on the basis of ideological dogma, or on the basis of some admixture of dogma and evidence. In any case, regardless of why we believe as we do, You and I disagree, in a perfectly familiar way.

Suppose next that the two of us are subsequently exposed to a relatively substantial body of evidence that bears on the disputed question: for example, statistical studies comparing the murder rates for adjacent states with and without capital punishment. The evidence is of a mixed character: some studies seem to suggest that capital punishment is a deterrent while other studies seem to suggest that it is not.  regardless, the entire body of evidence is presented to each of us: there is no piece of evidence that is available to you but not to me, or vice versa.

What becomes of our initial disagreement once we are exposed to such evidence? It is natural to expect—and perhaps, also natural to hope—that mutual exposure to common evidence will tend to lessen or mitigate our disagreement. Perhaps it would be unrealistic to expect a perfect convergence of opinion: after all, we begin with diametrically opposed views, and one might expect this fact to find reflection in our later opinions. Still, it’s natural to expect that our exposure to common evidence will tend to narrow the gap between us and that, indeed, as the total evidence which is available to each of us increasingly comes to consist of common items, our views will undergo a corresponding convergence. (A Bayesian might speak here of the ‘swamping’ or ‘washing out’ of our respective prior probabilities.) At the very least, one would expect that exposure to common evidence would not increase the extent of our disagreement.

In fact, however, if You and I are typical of subjects who have participated in actual experiments of exactly this sort, such natural expectations will be disappointed.

Exposure to evidence of a mixed character does not typically narrow the gap between those who hold opposed views at the outset. Indeed, worse still: not only is convergence typically not forthcoming, but in fact, exposure to such evidence tends to make initial disagreements even more pronounced. The more I am exposed to evidence of a mixed character, the more confident I tend to become of my view that capital punishment is a deterrent. On the other hand, the more You are exposed to the same evidence, the more confident You tend to become of your initial view that capital punishment is not a deterrent. As our shared evidence increases, each of us tends to harden in his or her opinion, and the gulf between us widens. Our attitudes become increasingly polarized.

Read further: Disagreement – Dogmatism and Belief Polarization in Princeton website

Read further in the Muslim Times: Kripkean dogmatism