As far as I'm concerned, my brain is a complex organ that processes input through the senses and analyzes it, as well as directing my body what to do in the situations I encounter. My personality is nothing more than the sum total of the lessons learned from my experiences with this sensory input, and the behaviors I have learned to use for interaction with the things that input represents. If there is some sort of "soul" not made of matter or energy, I would like to see evidence of it. To say that something is not made of matter or energy, that it is "immaterial", is to say it does not exist. How can anything exist and be real which does not interact with the existing matter and energy in measurable ways? There is no reason for me to believe that I am nothing more than a conglomeration of cells.