In “I am a strange loop” (2007) Douglas Hofstadter proposes that the self, personal consciousness, is a pattern. Hofstadter notes that patterns exist at different levels of resolution, ie at different points on a spectrum of granularity, from coarse-grained to fine-grained.
Here’s an example: Jack and Jill are persons who know each other. Per Hofstadter’s idea, the knowledge of Jill in Jack’s mind is as much a valid part of Jill as Jill’s physical body is part of Jill. But the knowledge of Jill in Jack’s mind is “low res.” compared with the knowledge of Jill in her own mind — the former is “lower res.”, the latter is “higher res.”
Extending the idea: A photograph of Jill is part of Jill. A biography of Jill is part of Jill. Letters written by Jill are parts of Jill. Clothes worn by Jill are parts of Jill. After Jill’s death, memories of Jill in the minds of people who knew her in life, are parts of Jill. Every part and aspect of reality touched by Jill in any way, is part of Jill — the “Greater Jill”, the total, aggregated footprint of Jill upon Reality.
Perhaps the most significant difference between the various parts or aspects of Jill is the extent to which each is subject to change. Everything is subject to change, but some things change less than others. A digitized photograph of Jill uploaded to the internet is less subject to change than Jill’s physical body.
A useful way to think about it is in terms of process vs pattern. What’s the difference between a pattern and a process? Answer: change/movement. A process is a dynamic pattern. A pattern is a frozen process, a static process. The self, personal consciousness, in life is a process and in death is a pattern. After Jill’s death, the dynamic process “Jill” is frozen and what remains is the static pattern “Jill”, which resides in the minds of people who remember her and in photographs and other records.
Every process needs a substrate on which to “run”, on which to deploy itself. Computer software runs on a substrate of computer hardware. The process of delivering energy into the homes of people (currently!) runs on a substrate of metal wires. The process of removing personal waste from the homes of people runs on a substrate of pipes in the ground. The process of being a person runs on the substrate of a flesh-and-blood body. Consciousness/mind is a process that runs on the substrate of the brain.
Consciousness is a verb, not a noun.
A person is a composite monad comprising “software”, “hardware” and “data”. Mental content, the software, is deployed on a flesh-and-blood hardware substrate, the brain. The person’s experiences and interactions with the world are data.
When the substrate ends or is destroyed or vanishes into the mist, the process stops and can run no more. In the case of the process of being a person, when the body dies there’s no substrate on which the person can run, so the person runs no more. When the brain dies, consciousness/mind stops and can run no more unless and until another appropriate substrate takes the place of the brain.
But there’s nothing in principle preventing a process from running on multiple substrates, serially or in parallel. The death of the body does not necessarily mean the final and irreversible death of the personhood associated with that body. In principle, if and when another suitable substrate becomes available, the process of being that person could run again (as long as it had been appropriately stored in the interim!). Reincarnation is what happens when a new substrate becomes available on which the process of being a particular person can run again.
OK, but what happens to the process while it’s waiting for a new substrate to turn up? I don’t know. Perhaps it runs on the fundamental substrate on which the whole of reality runs: the Higgs Field? Could a process run on itself as substrate? Could a process itself give rise to a virtual substrate on which the process could run? Don’t know.
In principle, the substrate on which runs the process of being a person need not be organic, ie based on molecules of carbon. The substrate can be anything on which the process can successfully run. The substrate could, for example, be silicone-based (as in the case of the computer). But the substrate need not be material at all; it could be a “virtual substrate” comprised of abstract principles of internal logic.
There are many different types of immateriality, as many as the number of angels that can dance on the head of a bindu.