So while I was researching for next project; creating 5 book covers due next wednesday. I'm doing a book cover based on Design Aesthetic Philosophy (or design philosophy, basically what I write about). I came across a philosopher whom I haven't heard of; Prof. Arnold Keyserling. He was all about brain coherence and the grammar of the brain. To me, Graphic Design is thinking made visual... that's the definition I go by (while I realize GD has many definitions this is one I found that is most appropriate). I found his use of the enneagram; the nine-pointed star very interesting.
Keyserling discovered that the structure of our brain molds our speech, and our speech in turn shapes our mind. He found that the basic patterns of our mind and coherence are tied to language, and all are tied to the Enneagram and The Wheel. The essential criteria of our mind can be reduced to the three space-like realms of language combined with the four time-like functions. These are the basic components of The Wheel. (source)