If something (spirit) does not interact with matter, then it can not influence any physical event. Thus spirits (souls, ghosts, etc.) do not exist in physical world, only in spiritual (=person's imagination).

That is OK, it was reported by doctors many times that people who see ghosts and visions on a regular basis (usually children) are hallucinating. Hallucinations, dreams, visions, etc are physical phenomena (activity of vision neurons at the absence of signals from eye) and are documented well.

• Teleportation - dolphin - October 30, 2001 - 05:23 UTC
• Hallucination ? - aximili - October 30, 2001 - 09:36 UTC
• Spirit is equivalent to imagination - yanniru - October 30, 2001 - 15:35 UTC