1998 The Mind of a Centaur




The Mind of the Centaur

Neil Greenberg

Department of Ecology and Evolutionary Biology

University of Tennessee, Knoxville

University Studies Colloquy Centripetal Presentation

Wednesday, 1 April, 1998


SUBCOMPONENTS of our Nature have been long recognized:

  • “When the gentler part of the soul slumbers and the control of Reason is withdrawn . . . the Wild Beast in us . . . becomes rampant.”  (Plato, The Republic, IX 571)
  • “We are conscious of an animal in us which awakens in proportion as our higher nature slumbers” (Henry David Thoreau in Walden)

CONNECTIONS between subcomponents are central to our humanity:

  • “Only connect! . . . Only connect the prose and the passion, and both will be exalted, and human love will be seen at its height. Live in fragments no longer. Only connect, and the beast and the monk, robbed of the isolation that is life to either, will die.”   (E.M. Forster, Howards End (1910) ch. 22)

THE CONNECTION is the bridge to the future of our species:

  • “Upon the platform of our passions we strive to build a bridge to higher consciousness . . . And through that consciousness we proceed, generation by generation, to the high ground of transcendent human possibility.”  (Re-Creations, 1941,  ch.1)

The Mind of the Centaur

  • The incompletely integrated central nervous systems of  Homo sapiens reflects the tension between the ancient agenda of the animal mind and that of humans striving for freedom from the vagaries of the environment in which they evolved.
  • The Centaur presents an ideal natural experiment in cerebral integration

BRAIN EVOLUTION: excavating the paleopsychology of our species:

  • “The Brain of Man has not abandoned it’s ancient animal foundations, it has built upon them . . . . But it has also reconstructed them as the shifting earth beneath dictates . . . . We have done the best possible in the landscape in which we have found ourselves with the raw materials we have inherited.” (Prolegomena to a Study of Mind, 1973,  ch. 42)


Paul D. MacLean’s (1968) “triune” view of the mammalian brain called attention to the modular substrate of behavior.

  • Surrounding the “reptilian” basal ganglia –controlling habit– we find . . .
  • The “paleomammalian” limbic system — substrate of our passions–  embraced by the cingulate gyrus.
  • The “neomammalian” brain based in the neocortex then coordinates inner and outer representations with projections of the future consequences of alternative actions –foresight.

The physical evidence provided by the Centaur of Volos in the Hodges Library has enabled studies providing an unprecedented precision of extrapolation from osteology to neuroanatomy and implicit neurochemistry.


page from laboratory notebook

  • Five heteronical conflationary eigen-components were reduced to…
  • Two really rather nice post-synaptic vectors which devolved upon an exquisitely poised articulation of inhibitory and excitatory impulses…
  • Which correspond to discriminable assemblies of behavioral dispositions to act in specific ways to specific stimuli and which are known collectively as “BELIEF SYSTEMS”

BRAIN-CENTERED BELIEF SYSTEMS: integrate and guide our behavior:

  • The CENTAUR BELIEF SYSTEM is based in our affect-generating limbic system and involves impulsive action . . .
  • The HUMAN BELIEF SYSTEM  is centered in our neocortex and involves foresight. It can override The CENTAUR SYSTEM.
  •  Each belief system (BS) was found to correspond to a HIGHER  and  LOWER referential process, respectively . . . which reciprocally alternated activation of an inhibitory “executive” cell — a neural process familiar to by many University faculty members as “waffling.”


 Centaur BS: Affect drives system;  Rapid response;  Rationalized by reason

  • Human BS: Reason drives system; Involves planning; Motivated by affect
  • Reciprocal BS: automatized responses adjusted whilst in progress as they are integrated with complementary responses;  Integration through forebrain enables executive override;  The most highly evolved BS of all
  • The fundamental differences between brains (as for example between men and women, human and Centaur) were masked by their superficial anatomical similarities.   However, at the microscopic and cytochemical/molecular levels, important differences can be detected: the connection is
  • Neurochemical !

  • The great Centaur physician, Chiron, had discovered that certain substances can disarticulate lower and higher referential processes, ordinarily connected by the dynamic physiological balance of cerebral modules.
  • By the 16th century, this method was in general use for the most demanding experimental explorations of this critical juncture.
  • The ancient discoverer of this substance became the icon for its finest expression.  see notes on Centaur experimentation with neurochemical dissociation

Freud was among the first to recognize the dissonance between our origins and our ambitions and he spent his life seeking the formula for their transmutation:


His most important insight was catalyzed by a conversation he had with an old friend:


  • “Itzig, where are you riding to?”
  • “Don’t ask me, Sigmund, — 
  • ask the horse.


(Letter to Wilhelm Fliess, 7 July 1898, in Aus den Anfängen der Psychoanalyse)



Professor Emeritus, Department of Ecology and Evolutionary Biology, The University of Tennessee, Knoxville.