The world of physical phenomena can be investigated by science. Science has developed over the last two hundred years to put forward hypotheses, challenge them test them and develop theories about how the physical world behaves according to rules. In general this system works because we can make predictions about how physical things will behave and this has allowed the rapid development of technology so we know it works. Many people believe in a supernatural world. This world has been put forward in various forms to explain, the origin of all things, human free will and so on. If the supernatural world interacts with the physical world at some point the supernatural world actually has to manifest a physical effect. It has to, for example, start an electrical impulse that causes motor neurones to fire and our bodies to move. In the case of god he has to be able to create matter and energy that wasn't there before to move things about. God is a bit difficult to test because he doesn't always show up but the human soul must constantly be interacting with the physical world. It must be receiving information from the physical world, which means that physical energy must be disappearing into the supernatural world. This makes it a physical phenomenon that we just don't understand at the moment. Presumably believers think that if we manage to map all the physiological functions of the human brain we would be left with a gap – effectively a machine without a controller, a robot with no commands. Assuming this soul exists why can't we detect it? If we can some day detect it what is it made of? If it exists how does it work? How is my soul different from yours? How does it process physical information? Presumably the supernatural world is a world that co-exists with ours but only interacts along a certain interface. Are there rules for this interaction? What is the limit of the power of the soul? To me suggesting the existence of a soul as though it answers any questions is a very strange thing it just raises more questions. It just forces the question of consciousness out of the physical world and then I'm forced to ask well how does the soul's consciousness work?