Let's not forget that language and music are not merely trying to mimic nature. They have jobs to do: writing is for putting thoughts on the record, speech is for transmitting thoughts to others, and music is perhaps for something like evoking feelings in others. Language and music want to capture as much of the structure of nature as they can so that they have an easy ride into our brains, but they must serve their purpose, and will have to sacrifice nature-mimicry when it is necessary to do so.
So one can see how sacrifices of nature-mimicry may sometimes be part of doing business. But why should the sacrifices be up near the top, where we have greater conscious access? The principal reason for this is that if the earlier regions of the hierarchy receive stimuli that they can't make any sense of, then they will output garbage to the next higher level, and so all levels above the unhappy level will be unhappy. Breaking nature-mimicry at one level will break it at all higher levels.
For example, I have argued in earlier research and in The Vision Revolution that writing looks like nature. In particular, I have suggested that written words look like visual objects. But words do not necessarily look natural at all levels up the hierarchy. Strokes look like contours, and letters look like object junctions; and thus the lower and middle levels of your visual hierarchy are happy. But because in alphabetic writing systems the letters in a word depend on how it is spoken, there is no effective way to make entire words look like objects. (For example, the junction-like letters in the words you are currently reading are simply placed side by side, which is not the way junctions in scenes are spatially related.) Your highest-level regions, of which you are most directly aware, only notice the nonnatural look of written words. And when visual signs do more closely match the visual structure of objects at the highest levels, people do see the resemblance to nature—this is why trademark logos and logographic writing systems like Chinese look (to your conscious self) much more object-like than the words you're reading here.
My claim in this book that language and music mimic nature must be understood in this light. I claim that they mimic nature, indeed, but not necessarily "all the way up." The reason why writing, speech, and music don't obviously seem like nature is that nature is not being injected at the higher levels, perhaps—as we've seen with writing—in order to better accomplish the functions they are designed to carry out.
We see, then, why it is that the nature-mimicry in language and music has remained a secret for so many millennia. If only your lower-level visual and auditory areas could speak! They'd have long ago let you know that language and music are built like nature. Because those lower homunculi are part of you, there is a sense in which you have known about this ancient, deep secret code all along. Pieces of meat inside you knew the secret, but weren't telling. In this light, one can view this book as a kind of psychoanalysis—if you're into that—digging up the homunculus-knowledge you already have deep inside you, and working through the ways it shaped who you are today.
Reprinted by arrangement with Benbella Books, Inc., from Harnessed by Mark Changizi. Copyright © 2011 by Mark Changizi.