Are angels real? Are aliens? Are unicorns? If all three can exist in the same mental space (you are holding the trio in your head right now), can all three exist in the same empirical space? When we use language to say “something is real,” what does that expression actually mean? If saying “something is real” can mean different things to different people, then how can we make useful distinctions that help define what we mean when we say something is real? Even if we can come to some agreement over what we mean when we say “something is real,” how does that agreement affect what we are willing to accept as evidence to support the claim that “something is real”? Who gets to decide what counts as proof that something is real? And possibly the most formidable question in discussing these matters, how does “common sense” factor into this? Do we need to define “common sense” or, somehow, does common sense define itself?
For some people, the mere act of questioning the existence of angels is sacrilege. For another group of people, the existence of visitors from outer space is not just idle speculation, but the consequence of what they claim to be first-hand observation. Perhaps a majority of educated adults would consider a discussion of the actual physical existence of unicorns whimsical or silly, but beyond the disinclination to take seriously the manifest incarnation of a creature from fairy tales lies an inescapable and tacit understanding that human consensus of “what is real” has no impact on any ultimate reality that exists with or without us. Throughout most of human history, a general opinion held that the world was flat; however, even if there was a time eons ago when the entirety of the human population believed the world to be flat, that collective understanding did not have the slightest impact upon making the earth any less round.
As a typical adult living in the 21st century, I do not believe in the existence of unicorns, but if it ever turns out I am wrong about this, it would just be another item on the long list of ideas that ultimately I am mistaken about. Could there exist a physical dimension that shares the same empirical space we inhabit but lies beyond our ability to perceive it? Just because we remain entirely ignorant of something, does its existence rely entirely upon our discovery of it? How do we draw the line between imagined reality and absolute existence?
While some folks love to spend hours in meandering conversations discussing the existence of ghosts or magic or other esoteric topics, other people have no patience for speculating on anything outside their narrow range of experience. I would argue there is value in exploring ideas beyond wherever we draw the line between what is and is not real. Questions of existence, purpose, and meaning represent a rich legacy that enhances our lives and has occupied human thought since the first time in prehistory when humans developed the ability to look at the stars on a clear, dark night and articulate their wonder at simply being alive midst the vastness of all that is.
Questions regarding meaning and existence are important because as a society the dual skills of expressing our ideas, on the one hand, and considering the ideas of those who think differently than we do, on the other, sustain the central nervous system of civilization. Without the ability to share our ideas convincingly and the judgement necessary for evaluating the ideas of others, human development grinds to a halt. The value of these two skills, the cogent articulation of our own thinking and the sensible assessment of the ideas of others, cannot be overestimated in determining the long term survival of our species; they are the essential nutrients of human intelligence, and without them, humanity's collective ability to sustain itself withers and dies from the malnutrition of ignorance.
Although these two intellectual activities are mutually dependent on each other, the art of expressing one’s own ideas and the practice of assessing the merits of other people's ideas have distinct approaches to handling the complexity of reality. The ability to share one's ideas in a way that enhances both the credibility of the concept and the reputation of the one putting forth a notion for the scrutiny of others, we call “rhetoric.” The ability to consider both the internal consistency (how well what is being proposed by another fits with what that person has said before) and the external validity (how well what is being asserted matches with what has already been established before by others), we call “philosophy.” It is too early in this piece to discuss the intellectual and linguistic territorial battles that rhetoricians and philosophers have waged with each other to stake out the conceptual borders between them, but as a place to start, it is useful, perhaps, to agree that neither field works very well without the other, and that both offer windows on reality that are indispensable for the continued advancement of human understanding.