In an old Zen story, two monks argue over whether a flag is waving or whether it’s the wind that waves. Their teacher strikes them both dumb, saying, “It is your mind that moves.” The centuries-old koan illustrates a point Zen masters — and later philosophers, psychologists, and neuroscientists — have all emphasized at one time or another: human experience happens in the mind, but we share reality through language and culture, and these in turn set the terms for how we perceive what we experience.
Such observations bring us to another koan-like question: if a language lacks a word for something like the color blue, can the thing be said to exist in the speaker’s mind? We can dispense with the idea that there’s a color blue “out there” in the world. Color is a collaboration between light, the eye, the optic nerve, and the visual cortex. And yet, claims Maria Michela Sassi, professor of ancient philosophy at Pisa University, “every culture has its own way of naming and categorizing colours.”
The most famous example comes from the ancient Greeks. Since the 18th century, scholars have pointed out that in the thousands of words in the Iliad and Odyssey, Homer never once describes anything — sea, sky, you name it — as blue. It wasn’t only the Greeks who didn’t see blue, or didn’t see it as we do, Sassi writes:
There is a specific Greek chromatic culture, just as there is an Egyptian one, an Indian one, a European one, and the like, each of them being reflected in a vocabulary that has its own peculiarity, and not to be measured only by the scientific meter of the Newtonian paradigm.
It was once thought cultural color differences had to do with stages of evolutionary development — that more “primitive” peoples had a less developed biological visual sense. But differences in color perception are “not due to varying anatomical structures of the human eye,” writes Sassi, “but to the fact that different ocular areas are stimulated, which triggers different emotional responses, all according to different cultural contexts.”
As the AsapSCIENCE video above explains, the evidence of ancient Greek literature and philosophy shows that since blue was not part of Homer and his readers’ shared vocabulary (yellow and green do not appear either), it may not have been part of their perceptual experience, either. The spread of blue ink across the world as a relatively recent phenomenon has to do with its availability. “If you think about it,” writes Business Insider’s Kevin Loria, “blue doesn’t appear much in nature — there aren’t blue animals, blue eyes are rare, and blue flowers are mostly human creations.”
The color blue took hold in modern times with the development of substances that could act as blue pigment, like Prussian Blue, invented in Berlin, manufactured in China and exported to Japan in the 19th century. “The only ancient culture to develop a word for blue was the Egyptians — and as it happens, they were also the only culture that had a way to produce a blue dye.” Color is not only cultural, it is also technological. But first, perhaps, it could be a linguistic phenomenon.
One modern researcher, Jules Davidoff, found this to be true in experiments with a Namibian people whose language makes no distinction between blue and green (but names many finer shades of green than English does). “Davidoff says that without a word for a colour,” Loria writes, “without a way of identifying it as different, it’s much harder for us to notice what’s unique about it.” Unless we’re color blind, we all “see” the same things when we look at the world because of the basic biology of human eyes and brains. But whether certain colors appear, it seems, has to do less with what we see than with what we’re already primed to expect.