Boris Sidis

“ What appears early in the course of development is less firmly organized than what appears later on. The whole tendency of evolution is from stability to instability. The order of growth and instability is in the ascending scale from groups, through systems, communities, to clusters, and constellations. The simpler sensori-motor reactions are, both ontogenetically and phylogenetically, the first to appear in the course of evolution and they are also more stable than the more complex sensori-motor reactions. ”

“ We can possibly best realize the relation of instability to complexity of structure, if we regard life, including both physiological and psychic processes, as an ascending organization of sensori-motor reactions to the influences of the external environment. ”

“ Movements and body- coordination then begin to appear, such as turning the body to right or left, then sitting up, then creeping, standing, then walking, then talking, all involving more and more coordination of muscles and kinaesthetic sensations, aided by the association of sensations and sensori-motor reactions from different sense-organs. ”

“ The complex coordination of orientation and space adjustment, such as the maintenance of equilibrium, walking, running, jumping, flying, swimming, etc., represent more complex activity. A still higher aggregate is to be found in the association of groups and systems of sensori-motor reactions within the sphere of a sense-organ with the complex coordination of motor adjustment of the whole body. The highest aggregates are to be found in the association of all the motor reactions organized within the different spheres of sense-organs with the complex motor coordination of body-adjustments. ”

“ The submerged moments, though lying outside the direct group of the main focus, still exercise a great influence on the course of the moment's growth and development. The conscious controls the material supplied by the subconscious, while the subconscious by the quantity and quality of the mass of its material, in its turn modifies and determines the course of conscious activity. ”

“ These associations become more and more complex with the rise and growth of differentiation of sense-organs in the higher forms of Mollusca and the lower Arthropodes, giving rise to groups, systems, communities, reaching the cluster-stage, in the higher Arthropodes and the lower Mammalia, finally culminating in the complex functions characteristic of the constellation-stage, such as found in the sensori-motor reactions of man in his adaptation to physical and social surroundings. ”

“ The highest constellation has at its command lower types of psychic aggregates, and had it not been for these lower moments, the higher type would have lacked matter and activity for carrying on its own work. ”