People in science and technology, for the most part, maintain a working assumption of materialism: that the mind is an activity of the brain, that there is no soul or spirit beyond the mind, and that when the brain dies, the mind or soulPeople in science and technology, for the most part, maintain a working assumption of materialism: that the mind is an activity of the brain, that there is no soul or spirit beyond the mind, and that when the brain dies, the mind or soul ceases to exist. Empirically I've found that doctors are often staunch defenders of materialism. This seems to be because of the consistent correlation between locations of brain injuries and consequent changes in habits or cognitive faculties.
The death of my wife gives me a reason to re-examine the assumption of materialism. I'd accepted it without much thought in the past, but now I have a more compelling interest in its veracity or lack of it. Being a geek, schooled in the ways of geeks, I took plenty of math and science courses, including probability and statistics, including hypothesis testing, as part of a course on detection and estimation. I also learned about the scientific method.
What does the scientific method tell us about the theory of materialism? It says that materialism is a viable theory only (A) if it makes falsifiable predictions, and (B) none of those predictions has yet been falsified by empirical evidence. Can we ever prove a theory is correct? No, theories can be disproven, but not proven. The closest we can come to proving a theory is to disprove all known competing theories, and the "proof" lasts only until there's a new competing theory consistent with the data known thusfar.
There are competing theories. Some of these are dualism (the idea that mental phenomena and physical phenomena are of fundamentally different stuff), idealism (the idea that there is really only mind, and physicality is an illusion), and functionalism, the idea that mental phenomena are fundamentally software, and can therefore exist on substrates other than brains (though I have a hard time seeing a conflict between materialism and functionalism, since functionalism only talks about how the material is organized).
Some dualists like the idea that there is "another world" inhabited by souls or spirits, which somehow influences this one. In this view, living means some kind of inter-world connection between a soul and a body which is broken when the body dies. Various questions remain unresolved, and the idea of two different, somehow-intersecting worlds just rubs everybody's esthetic sense the wrong way. I'd accept it if it were the only premise whereby my wife's spirit could somehow survive the death of her body, but it has the air of implausibility about it.
Another idea is that science will grow to include both physical phenomena and spiritual phenomena, and we will see that spirits or souls survive the death of the body and that it is ultimately sensible and reasonable that they should do so. This idea, which I admit is comforting to somebody with an engineering background, has been put forth by various psychics and mediums.
If you've seen N strange phenomena (where N is large) and you've shown all of them to be fraudulent, have you proven that no strange phenomenon can ever be genuine? No. Maybe the (N+1)-th phenomenon just happens to be the first geniunely spooky thing you'll ever see. William James commented that it suffices to find one white crow to disprove the proposition that all crows are black. He called Leonora Piper his white crow.
Now a lot of really stupid stuff has been said in defense of kooky ideas, and a lot of people making extraordinary claims have rightly been shown to be frauds. But there are some researchers, who've examined the data carefully, and conclude that the case for spooky stuff is really pretty compelling. Too few investigators are using statistical methods, but some of them are. That means we can have a meaningful debate about the merits of the data, the experimental methodology, and the interpretation of the data.