A hundred years ago the immateriality of soul was only seen as verifiable through paranormal powers: telekinesis, ESP, knowledge of the future, astral projection, table-turning, reincarnation or whatever. Everything else was taken as an embodied cognition that could be lost just as it could be impaired. But if human persons have spirits then spirit can’t just be exercised in its vastly infrequent and evidence-thin paranormal experiences, there must also be some spiritual dimension to mundane, everyday experience. So what is it?
Human consciousness differs from other animals by having knowledge itself as one of the things it knows. Other animals see physical things better than we do, but we also see physics; other animals have better perceptions of living beings than we have, but we can perceive biology. It’s our loss that we don’t have access to a physical science that might be developed by animals with radically different organs than our own or access to a philosophy of mind that might be devised by animals with nine brains, but we appear not to have it because there is none on offer. Until the aliens show up, we’re left as the only animal that compares what it knows to the world to see how it measures up.
But knowledge of knowledge is the act of a spirit, as is clear when we compare it to cognition by physical organs. We can smell a scent or taste a flavor but it’s meaningless to speak of the smelling of smelling or taste of taste. Even if we installed a third eye on a swiveling gooseneck we could only use it to see an eyeball, not to have vision of vision. Again, even if we hacked into the electrical signals in the eyeball or the occipital lobe that are interpreted as vision, the vision would still be in the interpretation, not the signals. We can see an organ just fine with another organ, but not the cognitive act of the organ, which is experienced within the organ or not at all. Where organs do the knowing there is no knowledge of knowledge, but this is what our experience of knowing most of all is.
Knowledge of knowledge, i.e. self reflection, is first of all what allows us to be a self or “I”. For all the deflationary philosophy thrown at the term, it remains the guarantee of both our spirituality and the possibility of our complete corporeality. When I say, for example, “I am digesting” or “I am sunburned and in pain” I identify myself with my body, even though doing so is only possible in virtue of reflexive spirituality. The stale division of theories of mind into dualist/ monist is, at best, the sort of crude first approximation that nature/nurture was, since it is precisely the dualism of the person into spirit and what is other than spirit that allows him to be fully identified with his body. The impressive acts of self-recognition done by chimps, elephants and magpies do not require their knowledge itself to be known to them and so ground what is, for us, an “I”.
Self reflection is also why we experience things in the world are true or false, i.e. as agreeing with our beliefs about them or not, or even how we can have beliefs at all. It is why I can form hypotheses or make guesses about the world and see if they’re right.
And so the experience of the spiritual soul is first of all our experience of being selves believing things as true or false, in other words, it is an experience of normal functioning human consciousness running across all levels of IQ and even across altered and impaired modes of consciousness. Drug users, for example, don’t cease to be selves experiencing things held as true or false. Without this basic human experience one cannot even say what he’s experiencing, though even apart from out ability to articulate the experience we still have it.