November 13, 1914] 



SCIENCE 



687 



environment, of conductors whicli transmit 

 the stimulation to the central organs and of 

 effectors vsrliicli control and direct the re- 

 sponses to the stimuli. The primary function 

 of the nervous mechanism is to provide paths 

 of conduction between the receptors and effec- 

 tors. The first breath of air at birth starts 

 the machinery of respiration. Irritability and 

 automatism are properties of all living things. 

 Even unicellular organisms, amebse, for in- 

 stance, in which there is no nervous tissue, 

 automatically respond to external stimuli, such 

 as food, and changes in behavior or rudimen- 

 tary and limited education can be developed 

 in them. As cell differentiation is evolved 

 the structure of the nervous system becomes 

 more complicated and its functions are more 

 diversified and effective. 



A sense receptor, such as the eye or ear, the 

 sensory nerve, such as the optic or the audi- 

 tory, the nervous center to which the impres- 

 sion is conveyed and the motor nerve, through 

 which the response is transmitted, constitute 

 the " reflex arc." Reflex action is the simplest 

 function of the nervous system. Strong light 

 induces contraction of the pupil, the sight or 

 odor of food causes the saliva to flow, pinch- 

 ing the flesh is followed by muscular move- 

 ment. These are examples of innate reflexes. 

 The normal child comes into the world pos- 

 sessed of these reflexes. A large part of edu- 

 cation consists in the coordination and de- 

 velopment of these innate reflexes. Walking, 

 talking, reading, writing, are examples of co- 

 ordinated, trained reflexes. 



The first lesson we learn in investigating 

 the mechanism of education is that the sense 

 receptors must be in good condition to start 

 with and must be kept in the highest state of 

 efficiency as we proceed. The receptors 

 through which our behavior is modified and 

 developed by environment are the five senses, 

 seeing, hearing, touch, smell and taste, each 

 of which, on close analysis, is found to be 

 complex. All primary knowledge reaches the 

 brain through these sources. In no other way 

 can environment modify our behavior or can 

 we be educated. The dictum of Locke, " Nihil 

 in intellectu est quod non prius in sensu," is 



not refuted by the addendum of Leibnitz, 

 "Nisi intellectus ipse." When the senses are 

 defective in function, illusions, hallucina- 

 tions and delusions control us and dominate 

 our conduct. The senses may be primarily 

 defective and to some extent these defects 

 may be removed by medical skiU. When nor- 

 mal in mechanism these functions may be im- 

 paired by poisons introduced from without the 

 body, such as alcohol, or by those generated 

 within the body, such as those due to fatigue 

 or to disease. Although the truth expressed 

 in the Latin proverb, " Mens sana in sano 

 corpore," has come down to us from classical 

 times, educators have been slow to realize its 

 force. Indeed, when mystical scholasticism 

 formulated educational ideals affliction of the 

 body was believed to be essential to the high- 

 est development of the mind. Fortunately, 

 even educators, one by one, with some reluc- 

 tance, are awakening from their dreams and 

 becoming interested in scientific investigation. 

 Greater benefits in educational methods have 

 been obtained by observation of the effects of 

 altered environment on the behavior of ani- 

 mals than have been evolved from the inner 

 consciousness of the greatest genius. Ap- 

 preciating the fundamental importance of 

 normality in securing an education, this uni- 

 versity is developing a splendid system for the 

 supervision of the health of its students. 

 However, the health of each individual is 

 largely in his ovsm keeping, and I wish to say 

 that idleness, alcoholism and sexual vice re- 

 main the most potent factors in student 

 wreckage. With senses untrained from idle- 

 ness and benumbed by dissipation, the indi- 

 vidual is a failure in coUege and in the 

 greater school of the world. 



Certain complex reflexes are known as in- 

 stincts. These play an important part in edu- 

 cation. All instincts are not manifest at the 

 time of birth, but develop with age and are 

 influenced by the evolution of the individual, 

 as a whole. The instinct of play manifests 

 itself in every normal child and the same is 

 true of the instincts of acquisitiveness, con- 

 struction, possession, self-assertion, anger, 

 self-abasement, rivalry, pugnacity, etc. These 



