Legion Theory is a meta-theory of psychology. It gives an overarching view of psychology and provides a common framework of explanation for many normal and abnormal psychological phenomena. The starting point for Legion Theory was an examination of the features of Mulitple Personality disorder (MPD), or, as it is now known, Dissociative Identity Disorder (DID). The most obvious feature of DID is the existence of multiple personalities within a single body, and so
The first pillar of Legion Theory is that, within the normal brain, the processes underlying our ‘self’ comprise parallel cognitive/personality/memory systems which act in an integrated manner to appear, under most conditions, to be a unitary system.
And so DID represents a failure of integration of these parallel systems.
Another important feature of DID, however, is the existence of multiple inner worlds. When not taking control of the body active alters often inhabit quite an elaborate inner world, and inactive alters are usually described as inhabiting still another world. This set us thinking about the nature of the world we experience and incorporating this experience of the world into Legion Theory.
Around two and a half thousand years ago the Buddha  said “With our thoughts we make the world”. That is, the “real world” we experience is actually an internal construction, or model, within our brains. This type of thinking entered Western philosophy when the 18th century philosopher Immanuel Kant  proposed that we don’t passively see objects, rather we impose “conceptions” upon the objects we perceive.
Early in the 20th century this type of thinking drove the Gestalt school of psychology following Max Wertheimer’s  description of the phi phenomenon – a type of apparent motion illusion. Wertheimer showed that if you presented people with two stationary alternating blinking lights they could see the image of a single light jumping back and forth between the two stationary positions. Although people could “see” this moving light, it didn’t exist. It was a construction of their brain – just as the rest of the world we “see” is a construction in our brain, and so
The second pillar of Legion Theory is that the brain constructs an internal representation of the external physical world, and it is the interaction of our self with this internal model of the world that we subjectively interpret as our ‘experience’ of the ‘real world’.
So, within your brain your “self” is constructed, and this self comprises parallel cognitive/personality/memory systems, which normally act in an integrated manner. And your self interacts with another set of systems which construct a model of the external physical world, and other worlds.
This second pillar of Legion Theory might appear to be an unnecessary complication to our model. Dare we say, an “intellectual wank”. But it isn’t if our goal is to have a true psychological meta-theory, because in some situations this distinction between “the real world” and the internal representation of the world serves to provide an understanding of people. And as we shall see, this distinction also serves to provide a model which provides great insight.
This distinction is important in clinical neuropsychology. Oliver Sacks in his book The man who mistook his wife for a hat , provides many examples of individuals who have suffered brain trauma resulting in problems in the construction of their world.
Often brain damage (from stroke, for example) is confined to only one side of the brain. So the damage usually only affects vision in one half of the visual field (left or right). A stroke in one hemisphere may cause cortical blindness, and the person is simply blind in one half of their visual field.
But the damage may cause more than simply blindness. It may affect the construction of the patient’s “real” world. Sacks describes Mrs S., who sustained damage to the right side of her brain . Damage to the right side of her brain resulted in Mrs S. being unable to construct a model of the left half of the world.
If, for example, her nurse placed a dessert on the left side of her tray, for Mrs S. the dessert did not exist. Mrs S.’s brain no longer constructed half of the world (the left half). If the left half of the world did not exist, then a dessert placed in the left half, similarly, did not exist. If the nurses told her that it was there, “on the left”, this didn’t help, as in Mrs S.’s world there was no “left”. If the nurses turned her head to the left, the desert would now be on Mrs S.’s right – and so now it existed. Mrs S. would proclaim that it hadn’t been there before. Mrs S. would sometimes complain that her portions were small (only half of what one would expect) as she would only eat from the right half of her plate. If Mrs S. wore lipstick, or applied makeup, she would only do so to half of her face – the half that, for her, existed.
Although in Mrs S.’s world there was no left, Mrs S. could appreciate intellectually that is must be there - somewhere. Her world, however, having no left meant that she couldn’t turn to the left to find it. She could, however, turn right. And if one turns right long enough, one eventually will find the unimaginable “left”. So Mrs S. requested and received a rotating wheelchair. If Mrs S. suspected that something should exist, but did not exist in her world, she would rotate to the right until she found it. So, if she finished her meal and felt that it had appeared to be too small (as she had in fact only eaten the right half of it), she would rotate to the right until she found some more. She would again eat all the food that, to her, existed on her plate (which was half of the half-meal). Finishing this, if she was still hungry, she would again rotate to the right, and find still more food – of which half exists in her world.
Sometimes brain damage, degeneration, or congenital problems, lead to problems in combining individual elements of the world into a sensible model. Dr Sacks also describes Dr P., one of his patients . Dr P. had nothing wrong with his sight. He could see a pin if it were placed on the floor and he was quite able to accurately describe the individual physical characteristics of an object presented to him. But the brain machinery putting this together to construct his world was faulty.
Sacks handed Dr P. an object to see if he could recognise it. Dr P. correctly identify its length (about six inches), that it had a convoluted red form at one end which was attached to something which was green and linear. Dr P. could not, however, put each of his acute observations of different features of the mysterious object together to form a coherent representation of this familiar object. At least, Dr P. could not do this with his vision. When given the instruction to use another sensory system, to smell it, Dr P. immediately knew it was a rose.
Legion Theory proposes the brain to produce two major sets of processes which underlie all human experience. One set of process constructs our self, and the other set constructs our world. The interaction of these two great sets of processes produces what we subjectively interpret to be our experience of the real world. But they do more than this. To understand all that they do we have to understand more about these two sets of processes.
- Buddha, circa 500 B.C.E
- Kant, 1787/1952
- Wertheimer, 1912
- Sacks, 1986
- Sacks, 1986, pp. 73-74
- Sacks, 1986, pp. 13-14
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Buddha, (Circa 500 B.C.E./1976). Dhammapada. Translated by Thomas Byron in The Dhammapada: The Sayings of the Buddha. New York: Vintage.
Kant, I. (1952). The Critique of Pure Reason. (J. M. D. Meiklejohn, Trans.). Chicago: Ecyclopædia Britannica, Inc. (Original work published 1787).
Sacks, O. (1986). The man who mistook his wife for a hat. London: Picador, Pan Macmillan Ltd.
Wertheimer, M. (1912). Experimentelle Stuidien über das Sehen von bewegung. Zeitschrift füer Psychologie, 61, 161-265.