In a physical sense of death, as we have observed in our physical world, our bodies will decompose (or experience another form of decay i.e cremation, being eaten, etc.) and all of us, every atom will eventually be returned to the Earth and reused again, probably by another organism in their life, taken in as nutrients. This is quite cool when you think about, because in a sense it is reincarnation, and even after you die you will still be giving back to the world.
Now a metaphysical sense.
To theorize an afterlife a few things must be determined to us first.
Things that (to me) need to first be determined
1. Are we alive, what does it mean to be alive
2. What gets passed on into an afterlife
3.Who has this quality
4. What manner of existence is this afterlife
For this I will be applying a philosophical argument for determinism vs free will. which says that 'science cannot be prove free will or determinism because science can only prove observable facts and truths. It can not be applied to theories that cannot be observed. Therefore what should be believed is that which appeals and gives the most logic to the ponderer.'
1 Are we alive
The first thing we need to determine is if we are truly alive. If we determine we are not then there is no chance of there being an afterlife as there is no life to begin with. Scientifically speaking yes, we have all the qualities that make something alive (cells, organization, use energy, response, growth, reproduction, and adaption). Another reason I believe we are alive because of our ability put together complex theories and ideas from observing on thing and successfully apply it to something else, and even more so of our interactions with the world around us.
2. What would get passed on
By this standpoint cells (the smallest unit of life) are technically alive, and can move on to an afterlife. Yet every interaction in a cell is cause by the natural reactions of the nonliving compounds inside the cell. What would become of the non-living compounds inside the cell, as they technically could not go to an afterlife, as they were never alive to begin with. For me to theorize an afterlife something needs to go on. For me this is a soul. While are bodies are technically just a complex series of interactions, I believe we are who we are because of our soul. I do not however believe the soul is created until the person starts interacting with the world. When we start to interact, much like our bodies, life begins to come into existence. I think two possibilities are here: (In its most basic sense)
a. Souls radiate some kind of metaphysical stimulant that begins the lifeforms creation of its own unique soul. It begins at birth and then grows exponentially as the life form develops and interacts with the world. This is my preferred theory, as it is similar in the age:understanding ration most people go through, and uniqueness is always appealing to me, as physically I'm different from everything else.
b. Souls from past dead wander around and look for new vessels to inhabit. I don't prefer this idea and find it a little disturbing, but consider it possible if there is no where to pass onto in an afterlife and souls are stuck here after death.
For all purposes I'm going to continue on with the former of the two hypotheses
3. Who has this quality
From the idea of developing souls, anything living and interacting can develop a soul, from trees, to bacteria, to humans, to rainforests, I believe all to have some sort of soul, and than therefore have an afterlife if deceased.
4. What is the manner of the afterlife
A comment/hypothesis brought up by my Biology teacher is one that got me thinking.
First, you are a sperm and egg, separate. This could be the first plane of life, then you come together and create a cell and this is the next plane of existence. Then your a fetus. All you know is the womb. Yes there is an outside that you have some interaction with, but you don't know what's there all you know is your mom's womb in this third plane of existence. Then you enter the fourth when you are born. You can interact further with what was outside the womb, yet your mind is still very closed off. Then you enter the fifth, most of the time in toddler years. This is when memories start coming, you become self aware, and you can interact with the world. This from memories and interactions is where I believe the soul takes existence. Perhaps we, here in this hypothetical fifth existence, are just waiting in another gestation period are just waiting to go into the next stage of existence and interaction and the birth into this existence, is our death; where much like we cast aside the sperm cell coat when leaving the first existence, we cast aside our bodies and a soul of memories transcends to the next.
This my preferred theory, and from this I believe we pass on rather than go to oblivion, reincarnation, or other existences. but the possibility of ghosts could exist too. Maybe someone died before their soul was fully developed and not ready to pass on yet. In response the soul remained here, but unable to get the massive interaction it used too, now can only grow through spectral phenomenon, and perhaps this manner of growth is extremely slower than growth in a body and therefore leading to the haunting of places for hundreds to thousands of years.
Besides the point, from there I like to believe we enter a state of eternal bliss where our soul, free from maladies of our world, can exist and grow among others as it pleases. Be it in a fantasy setting, a closer to this life setting or horror setting, it could change and exist there, in that state of reality to its hearts content and change its reality whenever needed, while somehow continuing the interaction with other souls.
This is what I like to believe as it makes me happy and comfortable, and I'll never really know until I die. All is expressed in my own opinion, and I'm not trying to criticize or damage any other's personal beliefs.
If you made it this fare thanks fro reading! <3