This idea, that we can divide and conquer the daunting problem of imagining how a person could be composed of (nothing but) mindless molecules, can be looked at bottom-up, or top-down, starting with the whole person and asking what smallish collection of very smart homunculi could conspire to do all the jobs that have to be done to keep a person going. Plato pioneered the topdown approach. His analysis of the soul into three agent-like parts, analogized to the Guardians, the Auxiliaries, and the Workers, or the rational, the spirited, and the appetitive, was not a very good start, for reasons well analyzed over the last two millennia. Freud’s id, ego, and superego of the last century was something of an improvement, but the enterprise of breaking down a whole mind into sub-minds really began to take shape with the invention of the computer and the birth of the field of artificial intelligence (AI), which at the outset had the explicit goal of analyzing the cognitive competences of a whole (adult, conscious, language-using) person into a vast network of sub-personal specialists, such as the goal-generator, the memory-searcher, the plan-evaluator, the perception-analyzer, the sentenceparser, and so on.
Philosopher Daniel Dennett's Book Intuition Pumps