> You can actually hypothesize that a soul exists and that intelligence is non-material, its just that your tests would quickly disprove that hypothesis - crude physical, mechanical modifications to the brain cause changes to intellect and character. If your hypothesis was correct you would not expect to see changes like that at all.

That’s not necessarily a disproof. It’s also not necessarily reasonable to conflate what we call “the soul” with intelligence.

This is entering the world of philosophy, metaphysics and religion and leaving the world of science.

The modern instinct is to simply call bullshit on anything which cannot be materially verified, which is in many ways a very wise thing to do. But it’s worth leaving a door open for weirdness, because apart from very limited kinds of mathematical truth (maybe), I think everything we’ve ever thought to be true has had deeper layers revealed to us than we could have previously imagined.

Consider the reported experience of people who’ve had strokes and lost their ability to speak, and then later regained that ability through therapy. They report experiencing their own thoughts and wanting to speak, but something goes wrong/they can’t translate that into a physical manifestation of their inner state.

Emotional regulation, personality, memory, processing speed, etc… are those really that different from speech? Are they really the essence of who we are, or are they a bridge to the physical world manifest within our bodies?

We can’t reverse most brain damage, so it’s usually not possible to ask a person what their experience of a damaged state is like in comparison to an improved state. We do have a rough, strange kind of comparison in thinking about our younger selves, though. We were all previously pre memory, drooling, poorly regulated babies (and before that, fetuses with no real perception at all). Is it right to say you didn’t have a soul when you were 3 weeks? A year? Two years? When exactly does “you” begin? I can’t remember who I was when I was when I was 2 months with any clarity at all, and you could certainly put different babies in doctored videos and I wouldn’t be able to tell what was me/make up stories and I’d probably just absorb them. But I’m still me and am that 2 month old, much later in time. Whatever I’m experiencing has a weird kind of continuity. Is that encoded in the brain, even though I can’t remember it? Almost definitely, yeah. Is that all of what that experience of continuity is, and where that sense is coming from? I’ve got no idea. I certainly feel deeper. Remember that we all are not living in the real world, we’re all living in our conscious perception. The notion that we can see all of it within a conscious mirror is a pretty bold claim. We can see a lot of it and damage the bridge/poke ourselves in the eyes with icepicks and whatnot, and that does stuff, but what exactly is it doing? Can we really know?

Intuitively most people would say they were still themselves when they were babies despite the lack of physical development of the brain. Whatever is constructing that continuous experience of self is not memory, because that’s not always there, not intelligence, because that’s not always there, not personality, because that’s not always there… it’s weird.

I think it’s important to remember that. Whenever people think they have human beings fully figured out down to the last mechanical detail and have sufficient understanding to declare who does and doesn’t have a soul and what that means in physical terms, bad things tend to happen. And that goes beyond a statement to be cautious about this kind of stuff purely out of moral hazard; the continual hazard is always as empirical as it is moral. We can never really know what we are. Our perceptual limitations may prove assumptions we make about what we are to be terribly, terribly wrong, despite what seems like certainty.