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Colour has been employed by
many people to illustrate, by analogy, the meaning of possessing knowledge
of an exceptionally intimate yet completely shared kind. Redness, for
instance, is experienced by all people, yet there's no way to actually
describe the sensation to another. We simply take it for granted that the
other person's impression must be same as that felt by oneself. The reason
is because red exists first as a physical property of a rose which is
chemically translated by the vision mechanism and electrically carried by
nerve impulses to the colour processing part of the brain. There, as if by
magic, It's interpreted as an experience called redness. Since we all have
identical equipment atop our necks, we conclude the experience must be the
same for all.
However, take the case of this writer who, along
with some 7% to 10% of the population, suffers from a congenital type of
partial colour blindness called dichromatism, This is a condition which
generally consists of the inability to differentiate between reds and greens or to perceive either reds of greens. Like it's no use telling us that red
is the hue of the longwave end of the visible spectrum, evoked in the human
observer by radiant energy with wavelengths of approximately 630 to 750
nanometres. It's no use because it makes perfect sense and, in any case, we
know it . But that's all; the empirical knowledge doesn't suddenly deliver
the colour red in our head.
But now watch, here's the
interesting part. Because in all other respects our vision is normal we go
through our lives without much of a sense of loss. And that's again because
we simply don't know what we're missing. If humanity were told tomorrow that
actually another colour called "zonk' exists which only aliens can see,
would our entire biological, social and cultural history of visual imaging
immediately get diminished in any way ? Of course not. Just like "darkness"
conveys nothing to the blind or" silence' to the deaf.
In addition, and remarkably
so, many of us in fact are unaware that we happen to be colour blind because
we can generally learn by experience to associate certain colours with
varying sensations of brightness. Thus roses appear red and grasses green,
even though they really don't. And we end up living happy in that blind
knowledge. Just like much more than a mere 7% to 10% of the population who
happen to be partially blind to things other than a simple colour or two end
up living their lives. |
