He suggested, first of all, that we don’t have one self, but several. Our psyches are made up of different competing systems, each with their own agenda. He suggested a tripartite structure – there is a rational, reflective system; a spirited or emotive system; and a basic system of physical appetites. One can compare this to the triune brain structure put forward in the 1960s by the neuroscientist Paul D. MacLean, who suggests humans have a reptilian instinctive system, a mammalian emotive system, and a neo-mammalian system of higher reasoning.
