REASON AND LANGUAGE. 141 



" Even the case of the deaf-mutes proves nothing to the 

 contrary ; for these unfortunate individuals, although not 

 able themselves to speak, nevertheless inherit in their 

 human brains the psychological structure which has 

 been built up by means of speech ; their sign-making 

 faculty is as well developed as in other men, though, 

 from a physiological accident, they are deprived of the 

 ordinary means of displaying it. Therefore we have 

 no evidence to what level of excellence the sign-making 

 faculty of man would have attained, if the race had been 

 destitute of the faculty of speech." 



But deaf-mutes never inherited the extraordinary 

 manual dexterity they show in manifesting their ideas. 

 Such special nervous connections, or hypertrophied con- 

 dition of nerves and ganglia as may be supposed to 

 have been induced by long descent through speaking 

 ancestors, they might have inherited. Such an inheri- 

 tance, however, could never have aided their gesticu- 

 lations. We must rather suppose that the nervous 

 conditions of abundant gesticulation must have been 

 going through a process of atrophy for ages, during all 

 the many generations of their loquacious fathers. More- 

 over, as we shall see almost directly, deaf-mutes do not 

 express their ideas in the order and sequence followed 

 in the spoken language of their fellows, but have a 

 special construction of their own. Yet this construction 

 could never have been inherited from their speaking 

 forefathers. A fortiori, then, their modes of gesticulation 

 could not be the outcome of their speaking forefathers. 

 As no amount of gesture-capacity could possibly by 

 itself have initiated the beginning of speech, so no 



