Koestler begins with a critical look at the overbearing and blinkered nature of behavioural psychology which attempts to quantify what is ultimately a subjective and therefore qualitative orientated study. He argues mental activity from decision to communication is more than simply Stimulus – Response which behavioural psychology of that period (1960s) largely focused on.
Koestler goes on to suggest the dichotomy of the individual whom is both an independent unique being and yet also part of a larger system (family, society, nation etc) drawing reference to the Janus complex.
Koestler describes the mind as having several shades of consciousness (rather than simply conscious or unconscious) describing the more mechanistic functions such as heart beat and homeostasis as the most mechanised, slowly working up to sensory motor reflexes, skills & habits and finally full awareness and decision making. Koestler highlights the more mechanised functions can be thrown into full consciousness at times of emergency, such as driving a car or riding a bike requires no real concentration until a danger is detected and full consciousness picks up the reigns to avoid disaster.
Koestler then looks broadly at evolution suggesting Darwinian natural selection and random mutation is also complemented by a form of ‘internal’ selection touching on the idea of some form of intelligent design. Simply put he suggests when a mutation or change happens (for example offspring are now born into a hard cased egg) a number of internal evolutionary changes happen to accommodate and take advantage of such change (the now egg imprisoned offspring also develop an appendage to break out of the egg) suggesting a coordinated control system.
Koestler then looks at the evolution of the human brain first drawing references to other species. Looking at invertebrates he interestingly points out a theorised ‘flaw’ in their design. Invertebrates have their ganglia (brain) underneath their digestive track rather than above as vertebrates do. He theorises this stumped the growth of the ganglia as too large it would press against the oesophagus and force the invertebrate to choose a bigger brain over the ability to eat. The spider, the smartest of invertebrates sacrificed the ability to eat solid foods (as it now simply ‘sucks’ juices from its prey) for a bigger ganglia.
Looking at humans Koestler describes the human brain seeing explosive evolutionary growth over a short period of the last 500,000 years and interestingly points out where as with other evolutionary changes in species in which newly acquired changes are used the human brain has grown to such a large size so quickly yet we as human are still learning how to use it. He draws reference to an amazing computer being very much under used and slowly the user starts to appreciate its full potential. It raises questions as to why the brain grew so quickly if it has never been fully used.
Koestler describes the brain in three sections: Oldest is reptilian - Archicortex. Homeostasis Then lower mammal - Mesocortex - can be related to the id. Feeling. Finally late mammalian - Neocortex - creates awareness. Thinking.
Koestler highlights that the explosive growth and poor linking of the Neocortex with older parts of the brain is the root cause of many mental illnesses and disorders. He also suggests more mundane mental states such as anxiety, depression, conflicting emotions and logical thought are all due to poor communication and harmonisation between these ‘three brains’.
He concludes with suggesting intra-specie killing and war is innate in humans because unlike ‘professional predators’ whom have developed natural inhibitions towards killing their own humans have not. He draws attention to the efficiency of killing in natural predators and therefore a need for evolution to impose natural inhibitions while humans never needed such inhibitions as they, until very recently, lacked and efficient way of killing their own specie. The explosion of the neo-cortex gave us the ability to craft weapons and now, without such inhibitions are free to kill indiscriminately.
Koestler concludes the book with an odd and in my opinion far fetched idea of subduing such ‘flaws’ in human brain evolution through popping pills.