68 DEVELOPMENT AND PURPOSE CHAP. 



the organism is not clear to me. 1 But at all events the 

 negative description Inarticulate will apply to both, and 

 what is said later of the general effects of this method of 

 correlation may be taken as a rule to cover both cases. Of 

 assimilation proper the simplest case is furnished by such 

 inhibitions of original impulse as have been described. 

 But there are others probably of the same generic type 

 though they are more advanced, and at least in their highest 

 development prepare the transition to a further method. 

 For example, a content A, the sound of a bell, which is 

 originally indifferent, proves to be the beginning of a short 

 continuous train of events culminating in the excitement 

 of dinner (B), and A in consequence becomes by slow or 

 rapid steps charged with the interest of B. By this method 

 the random efforts of an animal may lead to useful habits. 

 It may react to A at first in many vague and useless ways. 

 But one reaction gives B. This reaction, after one or many 

 repetitions, is preferred. All the others get the feeling- 

 tone of failure, one alone gets that of success, and so in 

 time A comes at once to prompt the right reaction. This 

 is the method of Trial and Error, which has been shown to 

 have great importance in the c learning ' of animals. 



But among ourselves B need not in all cases be a feeling. 

 Any element entering habitually into the same field of con- 

 sciousness with A may come to colour A with its own 

 nature. Any data that frequently impinge on one another 

 in our consciousness may become so bound up that to our 

 sense-apprehension one stands for all the rest. Such is the 

 character of perception as distinguished from mere sensa- 

 tion, of Recognition, and of all the operations in which we 

 detect what we call an unconscious inference. This name 

 is inappropriate only if it suggests that there is in con- 

 sciousness any transition from premise to conclusion. In 

 reality I see that wall as a solid object built of brick, though 

 in point of fact I could not by vision alone adequately test 

 its solidity, to say nothing of its composition. But many 



l lt may be noted that among Protozoa the evidence for selective 

 response is clear, and that for true assimilation very doubtful. Among 

 Coelenterata, however, true cases of the reversal of a response to stimulus 

 are reported. (See Washburn, The Animal Mind, p. 214.) 



