Maybe it's not like that at all, and for the sane and the insane to meet somewhere in the middle, a different concept is needed. Like how insanity isn't two-dimensional at all...it's not a coin - sanity and insanity. They're not opposite sides of a ha'penny piece.
The mental aberrations of some might be nothing more than a compulsion to check a front door lock, to entirely imagined but real-enough persons maneuvering a man through some horrific conspiracy.
But they're not simple. The mind isn't a graph. It's geographic. Cosmic, even. A vast thing beyond our cleverness. Not a wave, up and down, but three or four dimensional. Feelings and thoughts and beliefs that travel around a distant sun, changed by seasons and weather and the movement of the tides and all the celestial bodies which revolve around us while we, in turn, turn and turn around them.
It's not simple. It shouldn't be, either. A mind is a remarkable, wonderful thing, not to be taken lightly or glossed over or demoted to a picture drawn in graphite.
The mind is a universal concept, and one far beyond our ken. It's chaotic. It's supposed to be. What else would you like it to be? A calculator on a desk would be far duller by comparison, and never manage to dance or make poetry or love or art or horror.
There's something beautiful in the chaotic and the ridiculous that maths or science or religion all in their order can never better.
A partial image of the Large Magellanic Cloud.
There you go.