There is a lot of confusion regarding the location of the soul in the human body and its function in a living individual.Therefore the first chapter is a review of literature and beliefs about the soul. The second chapter is about the fate of the soul after it separates from the body at the death of the individual. There are only speculations about where the soul goes after it separates from the body. By applying some logic to these speculations I came to the conclusion that it goes to the astral world. There is scientific evidence of the astral world and methods by which it was discovered. The third chapter is about the exact role of the soul in living individuals. This involves the chemistry of life and interpretation of reactions between energy (soul ) and matter (body).The third chapter therefore is called 'Soul Body Interactions'. Since all the chemical reactions involve increase in consciousness of the soul which is not a visible evidence, I decided to include a chapter on evidence of consciousness in the plant and animal kingdom, because consciousness starts with creation of unicellular Beings and progresses step by step. Physical evidence of increase in consciousness is most evident in the evolution of the plant and animal kingdom, and with these evidence one can trace the evolution of the soul.