I agree that it's hard to conduct this debate without a definition of the soul, which probably can't be provided. But we can agree that it's nothing physical, but rather something like the core essence of our being, as different from anybody elses. A recent NPR show told the story of a man who was deprived of testosterone (for medical reasons) for weeks. All of his ambition left him, and he started staring at walls for long periods of time, never thinking about anything except to acknowledge its existence, and ascribed a single adjective to everything: beautiful. In other words, aspects of his personality he considered fundamental to being HIM, as opposed to someone else, were easily changed with the absence of a hormonal chemical. So we know that the soul, if it exists, would have very limited effect on the way you think logically about things or the way you perceive the world objectively. If you believe in some sort of God, then you probably believe that you were created by him, as an individual, and that relationship with God probably constitutes some of what a soul is. ' If you think God does not exist, I don't see how it would be possible to believe in the soul.