[read the disclaimer before proceeding]
Consider a clock that is ticking. We can think of the ticking as the “soul” or “consciousness” of the clock. As long as the clock’s spring or battery has sufficient power, the clock will continue to tick. When the battery runs out, the clock stops ticking. The consciousness of the clock ends at that point. The clock does not continue to tick in some kind of spiritual dimension – it simply halts. It seems only natural to apply this analogy to human consciousness: when electrical impulses stop propagating through the brain, human consciousness ceases to exist.
It seems to me that the idea of mind-body duality (that the body and the mind are somehow separate entities), and hence the idea of an afterlife, can be challenged with a short series of trivial observations.
The Brain
The very existence of a brain already casts doubt on the existence of a soul. If a separate, intelligent soul really exists and inhabits the body, why would the body need a brain? If all cognitive functions are indeed performed by the soul, then the brain becomes useless.
Brain damage can have profound effects on the body, ranging from paralysis, retardation, and of course death, to very subtle changes in the individual’s behavior or personality. Clearly, this alone is devastating evidence against the existence of a soul. If a slight modification to the brain causes a change in the personality of the individual, doesn’t this imply that the brain alone is responsible for the individual’s personality? What role, then, is left for the soul to perform?
One can make the argument that the brain is actually a “receiver” acting as an antenna of sorts, simply picking up signals from a soul that exists elsewhere. But this adds an unnecessary layer of complexity. If we make the argument that the complex structure of the brain is necessary to receive “signals” from an extra-corporeal soul, then why not simplify a bit, and admit that the complex structure of the brain is the source of the soul? It’s the same as suggesting that the Sun that we see in our sky every day is really a reflection from a giant space-mirror located where we think the Sun is, while the “real” sun is someplace else entirely, shining light onto the mirror.
Unfortunate Cases
When a mentally handicapped person dies, does his soul remain mentally handicapped for all eternity? Or does the soul somehow get “repaired” to a healthy state? If so, can the new soul really be considered “the same” as it was before the repair? The new soul would now possess cognitive abilities that the real-life person could never use in the real world. What good would these abilities be for the soul if it can no longer wield them in our reality?
When an infant dies, will the infant’s soul continue to exist in a perpetual infantile state? Similar to the previous example, let’s entertain that the infant’s soul will be “upgraded” to a healthy adult state. Frankly, this makes even less sense than the first example. In order for a soul to reach adulthood, the physical person needs to lead an actual life into adulthood, gathering knowledge, experience, and memories. What kind of memories (never mind knowledge and experience) can this hypothetical adult-baby possess if it never had any conscious experiences in the real world?
When an elderly person passes away because of a disease like Alzheimer’s, will the soul continue to exhibit symptoms of Alzheimer’s, existing in a weak, confused, and compromised state? Or will the soul be reverted to a time when the disease was not yet present? If this is the case, who decides the age to which the soul will be reverted? What about all the experiences and memories that the person collected as the disease progressed (fuzzy as they may be)?
Emotional Incentive
There also seems to be a suspiciously large amount of emotional incentive associated with the belief in souls and an afterlife, which would lead one to believe that the two are simply a product of wishful thinking. We don’t want to die, so we’d rather believe that we can survive death. Since it’s blatantly obvious that people don’t actually survive death, we invent the idea of a noncorporeal essence that represents our living “state.” This essence, conveniently enough, is only temporarily bound to the body, and thus survives death – problem solved.
Afterlife and Religion
One final problem is the utter naivete with which the major world religions (and therefore the majority of people) interpret the idea of an afterlife, inventing pseudo-physical “places” like heaven, hell, and numerous others where life continues indefinitely after death, with benefits and/or punishments based on the person’s behavior during life. The religious interpretation of the afterlife is primitive at best, and potentially quite dangerous. Indeed, any belief that cheapens real human life and attempts to misplace our hopes and dreams onto some intangible, imponderable promise of “eternal life beyond death” casts a truly negative light on the whole afterlife concept.