Given that I regularly have out of body experiences, it would make sense that I believe in a soul. There is a lot of interesting evidence for the soul, like near death experiences, communicating with the dead, and reincarnation.
Reality is more complicated than that though. It's important to study the facts, even if they're contradictory and don't paint a clear picture.
Some of the strongest evidence that the soul doesn't exist comes from studying what happens when brains are damaged.
The case of Phineas Gage is one example, where Phineas survived an accident where an iron rod was driven through his head. His personality changed drastically, described by his physician:
Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart business man, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was "no longer Gage."
Another interesting condition is Split-Brain, where people have the communication between the two hemispheres of their brain severed.
[One split-brain patient] reported to have grabbed his wife with his left hand and shaken her violently, at which point his right hand came to her aid and grabbed the aggressive left hand. However, such conflicts are very rare. If a conflict arises, one hemisphere usually overrides the other.
As you can imagine, there is a long history of studying the brain, and how damage can affect personality, memory formation, and perception.
For the rest of us, we can perform our own experiment. What happens to your personality if you drink alcohol?
If we can alter our personality by changing our brain, then it stands to reason that our personality arrises from our brain.
If the soul exists, then I would expect to see some quality of the soul expressed through the person that could not be affected by changing the brain.
What quality transcends the brain? If we can't come up with at least one, then either the soul is entirely passive, or doesn't exist.
In general, I find this argument very persuasive. What could a counter-argument look like? I will explore that in future posts.