My roommate stuck to the idea that everything including the mind originates inside the physical brain and there is nothing non physical. Though I felt my gut totally opposing this thought, it was difficult to really justify the existence of a non physical distinct mind overlapping the physical brain and body. I looked it up on the internet and it was interesting to find that very exact question in: Philosophy – Epistemology – Dualism vs Monism. It does seem like a perplexing question without an easy way to answer. I think the only way to really answer this is to maintain awareness even in deep sleep since in this state the brain activity slows down to 1hz – almost dead.