For most of my life I have never believed in a physical heaven or a material soul. As such, I tended to think of death through the popular scientific and atheistic notion that once brain activity ceases, there is no further experience.
More recently, however, I realized that there are some fundamental logical problems with the “nothing after death” idea. First of all, if we make any statement along the lines of “X after death” we have already presupposed an “after” element. This is certainly a coherent idea from a third person perspective. After I die, it is probable that others will attend a funeral for me, and I will be burried or cremated. If I am burried, anyone who were to dig up my burial site after a long enough time has passed will find a fleshless skeleton.
Of course, this is all from the perspective of others who are still alive and can still percieve a flow of time after I am dead. If we consider “after death” in a subjective sense, it starts to become less coherent. True nothingess excludes time itself. If there is no soul seperate from the body and brain, then a person lacking brain activity could not percieve any flow of time. Nothingness without time cannot include fear, boredom, peace or darkness. Nothingness is the absence of experience itself, and the absence of any duration over which anything can occur.
From the subjective perspective, how does the process of death reach completion? As one dies, one must eventually go from one point in time where they are not quite dead to the next moment where they are dead. This time T2 cannot, however, be subjectively reached. There is no “after”.
When asked what it is like to be dead, the question is often countered with “what was it like to not yet be born”. Of course, being not yet born is as equally incomprehensible as being dead. If there is no you, then these are not states you can be in. As an alternative, consider the moment you are experiencing right now, then consider the moment immediately before this. What if I told you there was a point in between those two moments of T=0 where you experienced literally nothing. This nothingness is itself equivalent to what death is subjectively.
One might counter this point by pointing out “yes, but in the first case experience resumes after the nothingness. When you die, you do not have any further experiences after this.” It is true enough that nothing more can be experienced by you if you no longer have brain activity or the capacity for perception. What this further means, however, is death is meaningless to the one who dies. As Epicurus says: “Where death is, I am not.”
While we are alive, it seems to us that “I am having an experience”. We are saying a roughly equivalent thing if we say that “an experience is being had”. Thinking about experience in the second sense, however, allows us to better tackle the problem of subjective death. Because any athiest would admit that you have no more experience after death as you no longer exist to have experience. At the same time, what disturbs us about death, beyond the egoist recognition that “the universe will move on without me” is that no more experience will be had once personal death has occured. Permanent nothingess.
What I have come to think now is that there is probably some sort of continuation of experience through other beings. One cannot carry memories of past lives as nothing physically transfers from one person to another. However, the stream of conciousness, the “experience being had” continues through beings which can experience as only the living can carry experience. To put it another way, non-experience cannot be experienced, so as long as at least one entity having experience exists, that is the being that the stream of conciousness continues through.
There are other solutions to the subjective death problem. One of which is the quantum suicide model in which ones conciousness always proceeds down the timeline in which they continue to live, no matter what is required for that to happen. Another possibility is that, just as we inevetibly wake up after going to sleep or going under anesthetic, we will, after death, come back to our awareness some time in the far future through some entity which carries our memories. In a universe which will continue to exist on the order of billions to trillions of years from now, there seems to be ample time for, say, an AI created by a future society to at random replicate your exact memories, or for a Boltzman brain to emerge spontaneously. I propose this last scenario with minimal seriousness. It is a pretty fantastical notion. It also assumes that life will exist for a significant portion of the universe’s future, which may not be true given the rate at which the universe is thought to be heading toward lower entropy.