90 Causes and Course of Organic Evolution 



ments of sense can never come into consciousness at exactly 

 the same time. Never simultaneously, but only successively, 

 can two impressions on precisely the same place in a sentient 

 surface be perceived as such." 



The above then is evidently the cognitic stage, where, as 

 in all nucleate plants and in animals, a capacity of more and 

 more rapidly perceiving, correlating, and responding to en- 

 ^^ronal stimuli unfolds. 



The gray matter of the brain, however, is at this time rapidly 

 forming and increasing in quantity, though as yet its functional 

 activity is feeble or wanting, as proved in cases of idiotic or 

 imbecile children at two or three years of age. In such, though 

 the cognitic activities may be fairly or quite active, the cogitic 

 are lacking, as is the needed gray substance. But the biotic 

 activities are now vigorously established, and act as a helpful 

 vegetative basis for the cognitic activities, as these in turn 

 are a fundamental need for the later establishment of the cogitic 

 capacity for perception and response. 



But in time a third step is made, and a higher stage is reached. 

 For, with increasing cognitic ability, sensations or perceptions 

 of external stimuli become linked together and reasoned on. 

 So "a sensation defined as to time and space, i. e., a perception 

 which becomes through the accession of the cause an object 

 of knowledge we call a representation, or an idea, or a thought. 

 Ideas are the exclusive contents of the whole higher intellectual 

 life" (Preyer id sup. 37). Such ideas in the average child 

 begin in the second or early in the tliird year, and steadily 

 strengthen thereafter up till maturity, when the brain — the 

 last and most complex organ of the body to mature — has ceased 

 to grow. This then, specially associated with the nerve cells 

 in the gray matter of the brain, as a material basis, represents 

 the flow of that most complex condensation of energy that we 

 have named the cogitic. 



If comparison be now made of the human organism in health 

 and disease, it might seem at first sight, when we study works 

 on nervous diseases or on psychopathology, that we are face 

 to face mth tangled and inexplicable biological phenomena. 



