Hi Caffeine,
PaulK's response and Modulous's addendum were pretty good answers to your question, so I'll just address this:
If we're abandoning the concept of a spirit, or a soul...
We're in a science thread. Science has never embraced the concept of a spirit or soul due to lack of evidence and so cannot abandon them. Within science the spirit or soul and all other concepts lacking evidence have no place in defining consciousness.
--Percy