52 SENSATION AND REACTION 



from them. This ability is instinctive, and is 

 born with us. But we have to acquire our stock 

 of memories for ourselves. Lower down the scale 

 of animal life amongst insects, for instance 

 sensations do not need to be adjusted by in- 

 ferences from experience : the necessary connec- 

 tions are made by instinct, and the young come 

 into the world fully equipped to meet its dif- 

 ficulties. 



Of what nature are the memories by which we 

 adjust our sensory impressions, and how do we 

 perceive them ? They are repetitions of former 

 sensory impressions, called up by the brain, and 

 are perceived by us by some faculty which may 

 be likened to sensation that is independent of 

 the special sensory apparatus of nerves and 

 nerve-cells. We look inwards as well as outwards, 

 or rather, we observe, as it were, a double 

 cinematograph show, in which two sets of pictures 

 are unrolled, the one resulting from sensory 

 impressions, and derived from the outside, the 

 other resulting from the repetitive faculty of the 

 brain, and evolved by it in association with, and 

 to correspond with, the sensory impressions. 

 When, as in children and backward races, the 

 memorial impressions of the brain are very vivid, 

 they can hardly be distinguished from sensory 

 impressions, and hallucinations result. We know 

 on what little excitement children will see 

 phantoms at night. Our grasp of what happens 

 outside us depends upon our ability to distinguish 

 the one set from the other. They are distinguished 

 in science by the names of " objective " and 

 " subjective," the former coming from sensation, 

 the latter from memory. 



It may be observed here that the memory may 



