It seems, by now, uncontroversial to assume that it is possible for a person to rationally hold religious beliefs. One might then ask, however: What distinguishes rational religious beliefs from irrational ones?
As an example – probably not the best, and also not originally my own – consider the difference between Alvin Plantinga and one of the 9/11 hijackers. I am of the opinion that Plantinga is rational in at least a large number of his religious beliefs, whereas the hijacker is not. My interlocutor, whose example this is, wants to know: What is the salient difference between Plantinga and the hijacker that makes the former rational and the latter not?
A few quick possibilities:
1. The difference could be that Plantinga’s religious is rational because he has considered some of the most damning arguments against them and provided rational reasons for rejecting them. I do not think this can be the salient difference, however, for surely Plantinga wants it to come out such that his grandmother’s religious belief – which is not based on philosophical argumentation – is rational, and I am sympathetic to his position.
2. It could be that Plantinga’s faith is rational because – but not solely because – it is situated within a community and tradition. This could apply equally to the hijacker being considered. If one were to claim that there’s a difference here in that the Wahaabist movement is not as old a tradition as Plantinga’s brand of Calvinism, that would certainly true, but it seems this would also exclude other newer groups, such as Pentecostals. Now, I have no particular affinity for Pentecostalism myself, but I do know a couple of Pentecostals who would be more than a bit upset about this.
3. Plantinga’s religious beliefs are rational because they are true, whereas the hijacker’s religious beliefs are not. Although I understand how this might work, it commits one to proving the truth of the belief system in order to establish its rationality, and it seems the hijacker could make a similar claim. Thus we are at an impasse. In addition, this solution seems to vindicate my interlocutor’s position that all religious beliefs are inherently irrational, since he rejects the truth of Plantinga’s religious beliefs.
So, is there another salient feature that solves this dilemma which I am missing, or should I resign myself to the fact that, for non-believers, all religious beliefs should be considered irrational?