How are we spirit?  In his classic work Matter and Memory, French philosopher Henri Bergson suggests that memory is the key.  In order for us to to fully understand memory, he suggests, we must turn to the realm of spirit, the etereal and beyond, the realm that we instinctively know is there, but which we cannot see or hear in the present moment.  Why?  Memory, he notes, is something that we experience, but cannot aurally see; we know it, but we do not materially perceive it.  Like spirit.
     Subsequent research on memory (Bergson published his book in 1910) has demonstrated that memory is indeed much more than meets the eye, but such research still cannot decide how we experience it.
     To wit, when we step into the fleeting transcendence of memory--and we all do--we see that our brains work in ways that we cannot always fully comprehend, that maybe, just maybe we need more than our cerebral folds to understand who we are.
     Enter spirit.