- What exactly is the soul?
Every soul is created directly by God at the moment of conception. The soul is non-physical and is created from the metaphysical nothing (nihil). The soul is very simple in structure and have no parts. The soul being created directly by God is a perfect structure. Having no parts it can't disintegrate so it's immortal.
- What does the soul do?
- What function(s) is the soul responsible for?
The soul is simple in structure but complex in function. Basically it's responsible for our will, intellect and abstract memory. It enhances all the mind properties produced by the brain too.
- What function(s) is our brain responsible for?
The brain indeed is responsible for some properties of our minds (the immortal soul is just a part of our minds). The brain produces what is called physical soul (or animal soul). This soul is mortal. Our immortal soul is connected with this physical soul. Catholicism say that humans have three souls: spiritual (Psyche), animal (anima, nephesh) and vegetative soul. The very union of the immortal soul and the physical soul is what is partially broken in humans. This physical soul is responsible for an instinctive will that is opposed to the spiritual will.
- What proof do you have that it is the soul and not our brain that controls every aspect of our consciousness?
There are animal brains much more sophisticated than humans and they don't produce consciousness. We have mental abilities not traceable to other species, so we have mental properties coming out of the blue (not traceable to biological evolution) like the sense of justice, beauty, perfection and infinity, etc. The gap between human mind and the other animals is practically infinite. How do you explain the Internet to your smart dog and cat?
- Where is the soul hiding? Area after area of the brain has yielded up its secrets to the probing of neuroscience, and not a trace of it has been found.
The soul is spiritual or metaphysical it can't be detected by scientific method.