Red Mars - Kim Stanley Robinson [108]
So the whole collection of extrovert-introvert traits, with all that they said about one’s character, could be traced back to a group of cells in the brain stem called the ascending reticular activating system, the area that ultimately determined levels of cortical arousal. Thus they were driven by biology. There should be no such thing as fate: Ralph Waldo Emerson, a year after his six-year-old son died. But biology was fate.
And there was more to Michel’s system; fate, after all, was no simple either/or. He had recently begun to consider Wenger’s index of autonomic balance, which used seven different variables to determine whether an individual was dominated by the sympathetic or the parasympathetic branches of the autonomic nervous system. The sympathetic branch responds to outside stimuli and alerts the organism to action, so that individuals dominated by this branch were excitable; the parasympathetic branch, on the other hand, habituates the alerted organism to the stimulus, and restores it to homeostatic balance, so that individuals dominated by this branch were placid. Duffy had suggested calling these two classes of individuals labiles and stabiles, and this classification, while not as famous as extroversion and introversion, was just as solidly backed by empirical evidence, and just as useful in understanding varieties of temperament.
Now, neither system of classification told the investigator all that much about the total nature of the personality being studied. The terms were so general, they were collections of so many traits, that they said very little in any useful diagnostic sense, especially since both were Gaussian curves in the actual population.
But combine the two systems, and it began to get very interesting indeed.
It was not a simple matter, and Michel had spent a fair amount of time at his computer screen sketching one kind of combinatoire after another, using the two different systems as the x and y axes of several different grids, none of which told him much. But then he began moving the four terms around the initial points of a Greimas semantic rectangle, a structuralist schema with alchemical ancestry, which proposed that no simple dialectic was enough to indicate the true complexity of any cluster of related concepts, so that it was necessary to acknowledge the real difference between something’s opposite and its contrary; the concept “not-X” being not quite the same thing as “anti-X,” as one saw immediately. So the first stage was usually indicated by using the four terms S, -S, S, and -S, in a simple rectangle:
Thus -S was a simple not-S, and -S, was the stronger anti-S; while —S was for Michel the skullcracking negation of a negation, either a neutralizing of the initial opposition, or the union of the two negations; in practice this often remained a mystery or koan; but sometimes it came clear, as an idea that completed the conceptual unit quite nicely, as in one of Greimas’s examples:
The next step in the complication of the design, the step where new combinations often revealed structural relationships not at all obvious on the face of it, was to build another rectangle that bracketed the first at right angles, like so:
And Michel had stared at this schema, with extroversion, introversion, lability, and stability at the first four corners, and considered their combinations. Suddenly everything had fallen into focus, as if a kaleidoscope had clicked by accident into a depiction of a rose. For it made perfect sense: there were extroverts who were excitable, and extroverts who were on an even keel; there were introverts who were quite emotional, and those who were not. He could