I've read a fair amount on Less Wrong and can't recall much said about the plausibility of some sort of afterlife. What do you guys think about it? Is there some sort of consensus?
Here's my take:
- Rationality is all about using the past to make predictions about the future.
- "What happens to our consciousness when we die?" (may not be worded precisely, but hopefully you know what I mean).
- We have some data on what preconditions seem to produce consciousness (ie. neuronal firing). However, this is just data on the preconditions that seem to produce consciousness that can/do communicate/demonstrate its consciousness to us.
- Can we say that a different set of preconditions doesn't produce consciousness? I personally don't see reason to believe this. I see 3 possibilities that we don't have reason to reject, because we have no data on them. I'm still confused and not too confident in this belief though.
- Possibility 1) Maybe the 'other' conscious beings don't want to communicate their consciousness to us.
- Possibility 2) Maybe the 'other' conscious beings can't communicate their consciousness to us ever.
- Possibility 3) Maybe the 'other' conscious beings can't communicate their consciousness to us given our level of technology.
- And finally, since we have no data, what can we say about the likelihood of our consciousness returning/remaining after we die? I would say the chances are 50/50. For something you have no data on, any outcome is equally likely (This feels like something that must have been talked about before. So side-question: is this logic sound?).
Edit: People in the comments have just taken it as a given that consciousness resides solely in the brain without explaining why they think this. My point in this post is that I don't see why we have reason to reject the 3 possibilities above. If you reject the idea that consciousness could reside outside of the brain, please explain why.
The reason for thinking that consciousness is a physical process of the brain is the remarkable correspondence we find between injuries to the brain or the introduction of various chemicals, and variations of conscious experience. That leaves open the possibility that consciousness is a physically separate entity for which the brain is the interface through which it moves the body and receives sensation from it, rather than brain processes themselves being consciousness. However most of the ground for that is undercut by the fact that some brain injuries severing parts of the brain from each other also appear to sever the corresponding parts of consciousness -- split-brain observations. It seems that it is not only components of consciousness that correspond to brain regions, but also their interconnection. The more we find out, the less role is left for the hypothesis of a separate consciousness to do any work. Like the old "God in the gaps" argument to defend theism against science.
That is the argument, but it is important to note what it does not solve. It does not solve the problem of what consciousness is -- of why there is any such thing in the world as experience, and how any physical process could produce it. Nobody knows the answer to that. (ETA: including non-materialists. "There are souls" is not an explanation of how they work.) In this it differs from the problem of God. There may be people who claim a direct experience of God in the same way as they have direct experience of themselves, but it does not seem to be common. Experience of one's own presence, on the other hand, is reported by almost everyone. Yet everything else we know about the world tells us that there cannot possibly be any such thing. We cannot even see what an explanation for experience would be.
There are those who point to some physical phenomenon that is present whenever consciousness is, and conclude, "that's consciousness". Unless they show how whatever it is produces experience, they have not explained consciousness. Most proposed solutions are of this form.
There are those who point to some more or less speculative physical process (e.g. quantum gravity in the microtubules) and assert, "that's consciousness". Unless they show how whatever it is would produce experience, they have not even speculatively explained consciousness.
There are those who take the apparently impossible magnitude of the problem as an argument that there is no problem, which is like a student demanding full marks because the exam was too hard.
There are those who claim to have realised that in fact they have no consciousness and never did (Buddhist enlightenment is often so described, and I believe that the psychologist Susan Blackmore has said something like this, but I can't find a cite). If they carry on functioning like ordinary people then they are claiming to be p-zombies, and if they don't, they've philosophised a tamping iron into their brain.
As for myself, I simply note the evidence above, the problem it leaves unsolved, and my lack of any idea for a solution. Yet it seems that few people can do that. Instead, as soon as they start thinking about the problem, they frantically cast about for solutions and latch onto something of one of the above forms. The problem is like a piece of grit in an oyster, provoking it to encyst it in layer upon layer of baroque encrustations that merely hide the problem instead of solving it.
We have as much reason to reject them as we have to reject the existence of a slice of chocolate cake in the asteroid belt.
Yes, this is a regrettably frequent error on this question.
But of course that is an explanation, in the same sense that Maxwell's equations explain the behavior of electric and magnetic fields. "We have this here thing, and is generates this here other thing, which is an observation we describe with this here equation". No different (disregarding the complexity penalty) from saying "souls generate experience" and if all you miss is the math-speak, then insert some greek letter for "soul" and another one for "co... (read more)