But very often sense education is most difficult for the adult, just as it is difficult for him to educate his hand when he wishes to become a pianist. It is necessary to begin the education of the senses in the formative period, if we wish to perfect this sense development with the education which is to follow. The education of the senses should be begun methodically in infancy, and should continue during the entire period of instruction which is to prepare the individual for life in society.
Æsthetic and moral education are closely related to this sensory education. Multiply the sensations, and develop the capacity of appreciating fine differences in stimuli, and we refine the sensibility and multiply man's pleasures.
Beauty lies in harmony, not in contrast; and harmony is refinement; therefore, there must be a fineness of the senses if we are to appreciate harmony. The æsthetic harmony of nature is lost upon him who has coarse senses. The world to him is narrow and barren. In life about us, there exist inexhaustible fonts of æsthetic enjoyment, before which men pass as insensible as the brutes seeking their enjoyment in those sensations which are crude and showy, since they are the only ones accessible to them.
Now, from the enjoyment of gross pleasures, vicious habits very often spring. Strong stimuli, indeed, do not render acute, but blunt the senses, so that they require stimuli more and more accentuated and more and more gross.
Onanism, so often found among normal children of the lower classes, alcoholism, fondness for watching sensual acts of adults—these things represent the enjoyment of those unfortunate ones whose intellectual pleasures are few, and whose senses are blunted and dulled. Such pleasures kill the man within the individual, and call to life the beast.
S—Sense, C—Nerve centre, M—Motor.
Indeed from the physiological point of view, the importance of the education of the senses is evident from an observation of the scheme of the diagrammatic arc which represents the functions of the nervous system. The external stimulus acts upon the organ of sense, and the impression is transmitted along the centripetal way to the nerve centre—the corresponding motor impulse is elaborated, and is transmitted along the centrifugal path to the organ of motion, provoking a movement. Although the arc represents diagrammatically the mechanism of reflex spinal actions, it may still be considered as a fundamental key explaining the phenomena of the more complex nervous mechanisms. Man, with the peripheral sensory system, gathers various stimuli from his environment. He puts himself thus in direct communication with his surroundings. The psychic life develops, therefore, in relation to the system of nerve centres; and human activity which is eminently social activity, manifests itself through acts of the individual—manual work, writing, spoken language, etc.—by means of the psychomotor organs.
Education should guide and perfect the development of the three periods, the two peripheral and the central; or, better still, since the process fundamentally reduces itself to the nerve centres, education should give to psychosensory exercises the same importance which it gives to psychomotor exercises.
Otherwise, we isolate man from his environment. Indeed, when with intellectual culture we believe ourselves to have completed education, we have but made thinkers, whose tendency will be to live without the world. We have not made practical men. If, on the other hand, wishing through education to prepare for practical life; we limit ourselves to exercising the psychomotor phase, we lose sight of the chief end of education, which is to put man in direct communication with the external world.