The belief of a soul or spirit that can exist independent of a brain is a romantic idea that I don’t often go out of my way to debate. After all, believing that the essence of one’s identity continues after death is an understandable comfort to those dealing with mortality. That said, I’ve been asked recently why exactly I don’t believe in disembodied consciousness and figure that here is the perfect place to record my thoughts.
Strictly speaking, this isn’t an atheist issue. The existence of a God doesn’t imply an afterlife nor does the absence of a deity imply that there can’t be a hereafter. The fact that the two beliefs are so often tied speaks to how religions have positioned themselves to appeal to desires in order to gain a following. By this I mean that a master who must be worshiped and a church that must be paid doesn’t fulfill many emotional wants, however, a master who can eternally reward worship and a church that serves as the proxy for heaven--that’s desirable to many. Still, the afterlife, like God, is an issue for skeptics. Neither can be proven or specifically understood and they both rely on supernatural assumptions. It’s impossible to say for certain that we don’t wake up somewhere else post-mortem, but below are my reasons for doubting.
There are many ways to show that my consciousness (or my mind/spirit/soul/self--depending on definitions) is directly tied to my physical brain. Drink too many beers and I become less inhibited, more friendly, and slower to process new information. Drink enough, and my consciousness goes on hiatus entirely--and booze is just the tip of the iceberg. When considering the full range of effects pharmacology has our brain, how can anyone deny that chemicals are a catalyst for how we think and behave? We observe higher levels of serotonin or dopamine when happy. Age wears down the brain as much as any other bodily organ--resulting in sluggish thinking, memory loss, and confusion--which in some cases are diagnosable as Alzheimer's or Dementia. There is a laundry list of contributing evidence that shows as goes the brain, so goes the mind. The reasonable conclusion is that when the brain goes completely, (dies) so does the self. I get it, it's a bummer, but desire does not dictate reality.