As is true of all models, the quadrune mind model of human consciousness is a simplification of reality. The diversity of people’s mentalities is much more complex than QM’s basic four: reptilian-like, old mammalian-like, new mammalian-like, and human. However, complex variations arise from the interactions of these four fundamental levels of consciousness. Understanding the dynamic relationships among the four minds can provide us a sophisticated method to describe and predict how these interconnected minds are revealed in our daily lives.
Scientific theory is built upon testing descriptive and predictive hypotheses of a model. In the theory of evolution, for example, the transitional organisms between the basic animal categories of reptiles, mammals, primates, and hominids are vague with many indeterminate species. Yet, the theory of evolution is considered to be one of the most robust theories in science. The developmental “stages” of human development; namely, infancy, childhood, adolescence, and adulthood, face similar breakdowns of categorization at the “micro” level of analyses. The social construct of “childhood” didn’t exist until about the turn of the seventeenth century, and it differs in meaning across world cultures. Nevertheless, sociologists can use the terms unapologetically in scholarly research with great practical and theoretical utility.
One of the best predictive models of reality is the Periodic Table of Elements, which allows chemists to discover new elements. But it would not be expected to provide equal descriptive or prescriptive value for quantum physicists. (Here is one example from the vast body of technical literature regarding the philosophy of chemistry and its relation to physics.)
Philosophical theories, as well as scientific ones, can also be tested by how well a model describes the phenomenological world or predicts future observations.
We believe that the inspiration for the quadrune mind, Paul MacLean’s triune brain model, has more value for us as a philosophy of mind than as a neuroscientific accounting of the brain’s structure and evolutionary history. We understand that there have been criticisms of his evolutionary analogues of pre-human behaviors. Nevertheless, we believe that the triune brain and quadrune mind models make significantly innovative contributions as multi-mind models of human consciousness.
This multilevel conception of “the” human mind is the best explanation of people’s behaviors, which otherwise would be inexplicable without an appeal to angels and devils on our shoulders. A multiple minds model also has predictive value for a person’s future behaviors based upon conceptualization of the present mental architecture.
Similarly, as to the models described above, an allowance for the loss of small-grained complexity in order to gain large-grained practical application is what we ask for the quadrune mind model. Or as psychologist Jay L. Brand said about a debate on another topic, “The trees, it would seem, stand up for endless scrutiny while the forest escapes without much notice.” Sometimes it’s looking at the forest that helps us better understand the world.
The Study Guide with “Resources” and our various blogs contain material in support of the quadrune mind’s descriptive and predictive value in the real world. Here are a few of the resources that contributed to the development of the quadrune mind model.
American Association of Neurological Surgeons. (1989, September 26). Paul MacLean, MD interviewed by Ayub Ommaya, MD. [The spirit of the man underlies the spirit of his model].
Brand, J. L. (2002). Why chance is a good theory [Comment]. American Psychologist, 57, 66-67.
Cory, G. A., Jr., & Gardner, R., Jr. (Eds.). (2002). The evolutionary neuroethology of Paul MacLean: Convergences and Frontiers. Westport, CT: Praeger.
Farley, P. (2008, Autumn). A theory abandoned but still compelling: In Paul MacLean’s triune brain, primitive emotions overruled conscious thoughts. Yale Medicine, 43, 16-17.
Lambert, K.G. (2003). The life and career of Paul MacLean: A journey toward neurobiological and social harmony. Physiology & Behavior, 79, 343-349.
MacLean, P. D. (1982). Triangular brief on the evolution of brain and law. Journal of Social and Biological Structures, 5, 369-379.
MacLean, P. D. (1983). Brain roots of the will-to-power. Zygon Journal of Religion and Science, 18, 359-374.
MacLean, P. D. (1985a). Brain evolution relating to family, play, and the separation call. Archives of General Psychiatry, 42, 405-417.
MacLean, P. D. (1985b). Evolutionary psychiatry and the triune brain. Psychological Medicine, 15, 219-221.
MacLean, P. D. (1990). The triune brain in evolution: Role in paleocerebral functions. New York: Plenum Press. [MacLean’s magnum opus].
Newman, J. D., & Harris, J. C. (2009, January). The scientific contributions of Paul D. MacLean (1913-2007). Journal of Nervous and Mental Disease, 197, 3-5.