Each soul is a soul or an individual by virtue of its having or I may say being a power to translate the universe into some particular language of its own.
—Ralph Waldo Emerson
What does it mean for something to be subjective? This means that it depends upon a perspective to exist.
Pleasure and pain are subjective, for example, since they cannot exist independently of an observer; they must be felt to be real. Mt. Everest, on the other hand, exists objectively—or at least we think it does—since that hunk of rock and snow would persist even if there were no humans left to climb it and plant flags on its summit.
Humans, of course, can never get out of their own perspectives and know, for good and certain, that anything exists objectively. Thus “objective” facts are really inter-subjective; that is, they can be verified by other observers.
Contrary to common belief, facts cannot be verified purely through experience, since experience is always personal and therefore private. This is why we are justified in disbelieving mystic visions and reports of miracles.
Two things must happen for raw experience to be turned into objective knowledge.
First the experience must be communicated to another observer through language. Language is a bridge between observers, allowing them to compare, in symbolic form, the reality they perceive. Language is a highly imperfect bridge, to be sure, and much information is lost by turning our raw experience into symbols; nevertheless it is the best we have.
Second, another observer must try to have an experience that matches the experience of the first one. This verification is, again, constrained by the vagueness of language.
Somebody points and says “Look, a helicopter!” Their friend looks up into the sky and says “I see it too!” This correspondence of experience, communicated through words, is the basis for our notion of the objective world.
(There is, of course, the thorny Cartesian question: How can we know for certain that both the helicopter and our friend aren’t hallucinations? We can’t.)
Subjective and objective knowledge share this quality. Our knowledge of the external world—whether a fleeting sensation of a chilly breeze, or a scientific doctrine repeatedly checked—is always symbolic.
A symbol is an arbitrary representation. All words are symbols. The relationship between the word “tree” and actual trees is arbitrary; we could also say arbol or Baum and accomplish the same end. By saying that knowledge is symbolic, I mean that the relationship between the objective facts and our representation of those facts is arbitrary.
First, the relationship between the external stimulus and our private sensation is an arbitrary one.
Light in itself is electromagnetic radiation. In other words, light in itself doesn’t look like anything; it only has an appearance when photosensitive eyes evolve. Our visual cortex represents the photons that strike our eyes as colors. There is only a symbolic connection between the objective radiation and the internal sensation. The red I experience is only a symbol of a certain wavelength of light that my eyes pick up.
As Santayana said, the senses are poets and only portray the external world as a singer communicates his love: in metaphors. This is the basis for the common observation that there is no way of knowing whether the red I experience is the same as the red you experience. Since the connection between the objective stimulus and the subjective representation is arbitrary, and since it is only me who can observe the result, we can never know for certain how colors look to other individuals.
When we communicate our experiences to others, we translate our direct experience, which is already a symbolic representation of the world, into still more general symbols. As I said above, much information is lost during this second translation. We can, for example, say that we’re seeing the color red, but we cannot say exactly what it looks like.
Modern science, not content with the vagueness of daily speech, uses a stricter language: mathematics. And it also uses a stricter method of confirmation: controlled experiments through which rival hypotheses are tested. Nevertheless, while stricter, scientific knowledge isn’t any less symbolic. To the contrary, modern physics is distinguished for being abstract in the extreme.
To call knowledge symbolic is not to discredit it; it is merely to acknowledge the arbitrariness of our representations of the natural world. Nature can be understood, but first we must translate her into our language. The truth can be spoken, but always with an accent.