I think we are already immortal, but does it really count if in every incarnation, you wake up with amnesia in a strange world, not of your choosing -- and if P.D. Ouspensky is correct -- to the SAME parents, SAME hospital, SAME town ....time is not linear, but it's like what you described re human evolution, it's circular, and in each repeated lifetime, nothing changes on the outside, but only on the inside -- your perception. Based on the evolution ...or not, of your perception, determines where on the spiral you will appear next. If, according to Ouspensky, you are E-volving, it will be further BACK in time. If you are DE-volving, then it will be further ahead in time.
Not to mention all of the parallel lifetimes and possibilities within that context!!
But according to this "model of the universe", the earth and it's inhabitants has a beginning and an ending ...the future moves toward that ending, so those who are devolving would move toward the future.
If you "transcend" a particular lifetime -- meaning you learn all there is to learn there, then you would incarnate into another's lifetime -- you would take the place of a soul who also moved either forward or back in time based on their state of evolution, and left an opening.
This makes total sense to me as it explains deja vu and a million other things ....but we were talking about immortality....
According to Ouspensky, if you continue to devolve, your soul or spirit eventually dies as it reaches the end of everything else, and is basically disassembled and absorbed back into "the light" or whatever you want to call it. So though the energy is not lost, that soul is basically dead.
Apparently one could keep repeating the same cognitive position or AP/level of evolution ....am at a loss how best to describe it -- for all of "eternity" ...neither evolving nor devolving but staying pretty much in the same place in time.
But is the endless cycle of birth, amnesia, learning or not learning and dying, really "eternal life"? I would say yes, but no.
Maybe you, and there are others who remember their past lives, but I am not one of them, nor have I met anyone who can ....but even if I could suddenly remember them, how would that change much ....since all I really need to do is achieve the "Totality of myself" -- which is contained in the Immortal Other/Double -- who has all of these memories intact -- who does not suffer amnesia, who is not limited to a certain form, planet, solar system, or even universe if I understand it correctly -- who may just be an Astral being at this point in "time" -- NOW -- but who will become much more when you and your Double become One -- "the perishable is made imperishable" -- the physical body and the Double become ONE ....into a being which is beyond the power of death to disassemble, and which can manifest fully in the physical if it chooses to.
But you speak of immortality as if it is a thing to get bored of ....I don't see it that way as there is no end to the possibilities of what you can experience, learn, do, be ....create! I am the opposite -- what I don't get is how any being would desire to come to and end -- whether that's at the end of one cycle in an endless series of incarnations, or as an Immortal being.
To me, this quote by Coon, is full of hints re the power and potential of the Double.