RE: Here's a theory...
There is no such thing as a spirit or at least an individually discriminable one as you can determine from the dissection of components that make up the mind, so no. The idea of souls as stuff-like is out of line with the fact that the quantised structure makes up everything in a individual, from thought to form, the thoughts that arise the individual are all physical. As for how quantised structures are self-experiential as one individual and not the other (and also not philosophical zombies) is another topic, though there are modernly sound theories as to why that is and I have a good general idea myself. Such theories behind consciousness include post-CEST and post-Orch-OR which are the result of the observations that compromised progressively the likes of materialism and panexperientialism via quantum theory, observed evolution and neuroscience.