> I agree, my point is that predisposition.

Well, I'd agree a lot of people choose ideas because of what they associate them with – as in, "religious people are boring and bigoted, science produces all these cool amazing new technologies, materialism is the science option and dualism/idealism are the religious options, so I'm picking materialism". From a strictly philosophical point of view, there are lots of holes in that argument – even if a non-materialist philosophy of mind is true, that does not in itself entail the truth of any particular religion, and (arguably) there are non-materialist philosophies of mind which are just as consistent with the results of contemporary science as materialism is – but, many people can't see those holes, so that kind of argument convinces them.

> Though I can’t help but adding… You can have a non material world without having an afterlife (telekinesis or spells working) and you can have an afterlife in a material world (via active intervention and time travel).

Telekinesis or spells could work in a perfectly material world. Imagine there was a swarm of nanobots which could read our minds, and are programmed to obey certain verbal commands – in such a world, telekinesis and spells would be completely real, but those facts would not in themselves make the world non-material. Furthermore, ideas such as Boltzmann brains and Poincaré recurrence suggest the possibility that an afterlife may be inevitable even in a purely material universe (although whether they actually do entail one gets into all kinds of complicated debates which I myself lack the competence to confidently decide.)

However, in another sense, my point stands. If materialism is true, it makes sense to identify the mind with the functioning brain, and hence to identify (presumably) irreversible brain death with the permanent cessation of the mind's existence; if materialism is false, that identification is a lot more open to question. With materialism, an afterlife is implausible, unless we rely on some highly speculative ideas (Boltzmann brains, Poincaré recurrence, simulation theory, etc). With idealism or dualism, an afterlife is much more probable, even without considering those kinds of ideas – if the mind does not necessarily depend on the brain for its existence, we have no strong reason to assume that the cessation of the latter must entail the cessation of the former.

> there are lots of holes in that argument

There’s holes in all kinds of things people believe. If you’re talking about actual belief systems then you can’t assume rational actors and logical thinking. Philosophy really doesn’t have the tools to explain what’s going on. We’re in the realm of psychology / neuroscience.

> to assume that cessation of the latter must entail the cessation of the former

Mind uploading blurs the line between life and afterlife because it wasn’t conceived of when those ideas were created.

IMO the conceptual framework that created the idea of a material world is really a delineation between magic rituals / religion and what people actually observed. The wacky nature of the observable universe is really orthogonal to the initial differentiation to the point where I think people would still talk about the material world in terms of things like fate and reincarnation even if spells worked.

> There’s holes in all kinds of things people believe. If you’re talking about actual belief systems then you can’t assume rational actors and logical thinking. Philosophy really doesn’t have the tools to explain what’s going on. We’re in the realm of psychology / neuroscience.

No doubt the average person's beliefs are full of holes, but education in philosophy and logic can make one aware of those holes, aware of one's hidden assumptions, the heretofore unconsidered alternatives to one's positions. I question whether psychology or neuroscience can offer us the same things.

> Mind uploading blurs the line between life and afterlife because it wasn’t conceived of when those ideas were created.

Nobody knows whether mind uploading is really possible. It is a purely speculative technology, its development could be centuries or millennia away, if it ever is developed at all. I also think its philosophical significance is overrated, since in principle it is just as compatible with idealism or dualism as it is with materialism.

> IMO the conceptual framework that created the idea of a material world is really a delineation between magic rituals / religion and what people actually observed.

I disagree. Most non-materialist arguments have as their starting point epistemology, not anything to do with magic, rituals or religion. Should our ontology straightforwardly mirror our epistemology (i.e. a first-person perspective is epistemologically fundamental and hence should also be ontologically fundamentally)–or invert it?