Many scientists, psychologists, philosophers and other folks in quest of understanding the Mind came to put in words the intuitive notion that we all have about our mind, that there are partitions in our head doing different things. Dreams, reflexes, emotions, projections, conversation, problem solving, live memories, all seem to stem from different places yet the lines are blur.
The brain is an organ, like liver and stomach. What we call the Mind is not a physical entity but the output of the brain. Some of its activities can be matched to actual activities of the brain but often many parts are involved and overlap in contribution. The actual physical activity of the brain is not of any use to us here and we will not try to match medical papers so we will purposely ignore the actual physiological identified portions of the brain the organ and focus on the organization of the mind. Below are a few distinct divisions that tend to recur through literature.
Although this chart is already an oversimplification of a perceived reality and even a generalization of the intended descriptions from the cited authors, it will be very useful for our purpose here. Most of these simplified divisions also overlap each other as well.
For instance, Kahneman places decision making in his system 2 associated with logical reasoning when others would locate decision making part of the emotional partition.
Below are a few functions attributed to each particular division by their respective authors. We actually favor the Core-Right-Left partitioning of Bill Williams and the Reptilian-Limbic-Neocortex division of the Triune Brain and basically will amalgamate them into Brain 1, 2 and 3. We may use the terms interchangeably in our articles when they apply best, so please refer to this chart when needed.