My comments on the second half of your essay. You wrote:
"Philosophers and others make such statements because they presume that materialism is true."
I'm not sure how to take the word "presume". Do you mean that materialists presume more than religious people, panpsychists, Cartesians, idealists, etc. presume? Do you mean that people accept materialism without thinking about it? Perhaps some people do. But are materialists any more likely to do this than I am, you are, etc?
"…. that the universe is nothing more than the interactions of particles obeying the laws of nature.."
Sorry for being semantic. What does "nothing more" mean? That is surely a rhetorical phrase. Most materialists don't believe the universe is "nothing more than..." They accept complexity, higher-order phenomena, that certain domains can't be well described or explained in terms of the "interactions of particles" (not just maths, logic and art, but even claims in astrophysics, biology, etc.).
"… that all this came into being through some kind of cosmic accident, that there is no God nor supernatural forces standing behind all this."
For every person who "presumes" that there is no God, there are 1000 who presume that there is a God. For every person who presumes that there are no "supernatural forces", there are far more people who presume that there are.
"It would therefore be reasonable to ask philosophers and scientists, before they make such statements, to demonstrate the truth of materialism, their underlying preconception."
I'm not sure how you can "demonstrate the truth" of materialism because it is a metaphysical doctrine. It's not like demonstrating truths in logic and maths. So what you say about materialism can also be said about anti-materialism and, indeed, all metaphysical doctrines. The words "proof" and "truth" are bandied around in these discussions and they’re neither apt nor useful.
"Of course they would find that very difficult; evidence suggests otherwise, although sceptical materialists always find ways to dismiss this evidence."
And religious and spiritual people, or anti-materialists, dualists, etc., also "dismiss" contradictory evidence.
"Murphy quotes Goff as saying that “materialism is dismal”. He says that this is not a proper philosophical comment, which may be so, but it is probably true nevertheless."
Okay. That is helpful. Philip Goff finds materialism "dismal". And you do too. I personally find it neither dismal nor not dismal. That is a genuine claim. I simply don't think in these terms. But if a philosopher does find materialism dismal, and states it openly within a context of talk about religion, spirituality, the ethics of panpsychism, Green and socialist politics, etc. - as Goff has often done, then you can see why such a person embraces panpsychism and/or anti-materialism (as Goff does). And you can see why they do so because they have explicitly SAID why they have done so. In the early years when Goff embraced panpsychism, he he never wrote about all this extra-philosophical stuff - at least not in his academic papers. Now these things seem to be his main theme.
"I am also currently dipping into a very interesting book called Materialism is Baloney by Bernardo Kastrup, probably an intentionally provocative title, one not suitable for a proper philosophical book in Murphy’s eyes."
I'm not against rhetoric in philosophy. As long as it can be backed up with argument, data, etc. Outside philosophy, rhetoric isn't usually backed up. And sometimes within philosophy it isn't backed up either. (Such as in much continental philosophy.)
"then much modern philosophy is based upon an illusion, the illusion of materialism."
... and I take "much modern philosophy is based upon an illusion" to be rhetoric. You might or might not have backed that up, but taken on its own, it's a rhetorical statement.
