Most of us would likely agree there are two major aspects of our being where we should aspire to be in good health: body and mind. A third, some would say, is just as real and important: spirit. The spirit seems to be the most difficult to quantify. For some time I have been struggling to construct a personal, working definition of "spirituality" that satisfies my need to adopt a convention others can readily relate to. I'm making some progress - I think.
First off, my burgeoning naturalist instincts notwithstanding, I do tend toward the notion that we do, indeed, possess a spiritual - or more precisely, a non-physical - persona, if only in the narrowest of interpretations. My personal spirituality assumes no association with the religious or supernatural. This may be problematic for some because of their strongly-held belief that spirituality is necessarily born of a supreme being. To me this is simply the expression of an idea flowing from one's personal belief system - or religious faith - and not something more universal.
Brain researchers have suggested we possess a natural affinity for the ethereal - or spiritual. (NPR, On Point: "The Science of Spirituality") This may explain why man has created for himself all manner of gods and supreme beings throughout history. Combining this with man's innate tendency to socialize also may explain how organized religions came into being. That is to say, religion seems to provide an efficient vehicle for the expression of our natural inclinations toward both spirituality and socialization.
In much the same way the totality of experience derived from the five senses - sight, sound, taste, touch, and smell - provide us with a sixth sense, so too does the totality of experience derived from our non-physical wherewithal, including thought, intellect, intuition, and the complete range of our emotions, provide us with our spiritual essence. In each case, the totality of assets considered creates a virtual entity greater than the sum of its parts.
This definition of spirituality may have trouble surviving my humanist - or naturalist - mindset. For now, I am resigned to the evolving nature of defining my spirituality. Hopefully, what I end up with will at least offer a point of reference accessible enough to encourage engaging discourse with others drawn to the same task. Such engagement would, no doubt be - spiritually - rewarding.