82 PHYSICAL BASIS OF CIVILIZATION 



Never before, but only after, this original experi- 

 ence and familiarity has been acquired can the other 

 senses save us from the slow and sure process of 

 identification by touch. Often a glance or a sound, 

 more rarely a taste or a smell, will instantaneously 

 inform us of a thousand things, qualities, relations, 

 possibilities, originally made familiar by touch. 

 Thus these other senses, and more especially sight 

 and hearing so far as knowledge is concerned, are 

 merely useful in extending and multiplying the uses 

 of the sense of touch. Sometimes the sensations 

 received through sight or hearing inform us of the 

 nature and qualities of objects great distances away. 

 At other times they leave us seriously in doubt as to 

 these. In such cases the aim is to approach near 

 enough to touch, and after touching the information 

 obtained by the sensations of contact are regarded 

 as absolutely trustworthy. Thus all human knowl- 

 edge primarily depends on the sense of touch. The 

 other senses would have left man forever deplorably 

 ignorant of the nature of the world around him 

 were it not for the acuteness of this sense, specialized 

 in human hands, fingers, and thumbs, and operated 

 by them in conjunction with the arms. 



How was the unique superiority and acute sensi- 

 tiveness of the human sense of touch originated 

 and preserved ? Whether running, walking, jumping, 

 climbing, or standing, the human body is supported 

 in an upright attitude by resting, by means of the 

 legs, on the soles of the feet. This prevents the 



