THE ORIGIN OF THE HUMAN SOUL 227 



word, reflective thought is a superorganic function expressing 

 the spiritual nature of the human mind. 



Another proof of the superorganic nature of the human 

 intellect as compared with sentiency, both exterior and in- 

 terior, is one adduced by Aristotle himself: "But that the im- 

 passivity of the sense," he says, "is different from that of 

 intellect is clear if we look at the sense organs and at sense. 

 The sense loses its power to perceive, if the sensible object has 

 been too intense; thus it cannot hear sound after very loud 

 noises, and after too powerful colors or odors it can neither see 

 nor smell. But the intellect, when it has been thinking on an 

 object of intense thought, is not less, but even more, able to 

 think of inferior objects. For sense-perception is not inde- 

 pendent of the body, whereas the intellect is." ("Peri 

 Psyches," Bk. Ill, Ch. iv, 5.) 



This temporary incapacitation of the senses consequent upon 

 powerful stimulation is a common experience embalmed in such 

 popular expressions as "a deafening noise," "a blinding flash," 

 "a dazzling light," "a numbing pain," etc. Weber's law of the 

 differential threshold tells us that the intensity of sensation 

 does not increase in the same proportion as that of the 

 stimulus. On the contrary, the more intense the previous 

 stimulus has been, the greater must be the increment added to 

 the subsequent stimulus before it can produce a perceptible 

 increase in the intensity of sensation. In short, stimulation 

 of the senses temporarily decreases their sensitivity with ref- 

 erence to supervening stimuli. The reason for this momentary 

 loss of the power to react normally is evidently due to the 

 organic nature of the senses. Their activity entails a definite 

 and rigidly proportionate process of destructive metabolism in 

 their bodily substrate, the organism. In other words, the exer- 

 cise of sense-perception involves a commensurate process of 

 decomposition in the neural tissue, which must afterwards be 

 compensated by a corresponding assimilation of nutrient ma- 

 terial, before the sense can again react with its pristine vigor. 

 This process of recuperation requires time and temporarily 



