SECT. XI. 3. SENSORIAL ACTIONS 61 



from fenfation, which is the actual exiftence or 

 exertion of pain or pleafure. 



Other dalles of difeafes are owing to the excef- 

 five promptitude, or fluggiflinefs of the conftitu- 

 tion to voluntary exertions, as well as to the quan- 

 tity of defire or of averfion. This fufceptibility of 

 the fyftem to voluntary motions is termed volun- 

 tarity, to diftinguifh it from volition, which is the 

 exertion of defire or averfion ; thefe difeafes will be 

 treated of at length in the progrefs of the work. 



Affbd&tltih* 



III. t. It is not eafy to aflign a caufe, why thofe 

 animal movements, that have once occurred in fuc- 

 ceflion, or in combination, mould afterwards have 

 a tendency to fucceed or accompany each other. 

 It is a property of animation, and diftinguifhes this 

 order of being from the other productions of na- 

 ture. 



When a child firft wrote the word man, it was 

 diftingui/hed in his mind into three letters, and 

 thofe letters into many parts of letters ; but by re- 

 peated ufe the word man becomes to his hand in 

 writing it, as to his organs of fpeech in pronounc- 

 ing it, but one movement without any delibera- 

 tion, or fenfation, or irritation, interpofed between 

 the parts of it. And as many feparate motions of 

 our mufcles thus become united, and form, as it 

 were, one motion ; fo each feparate motion before 

 fuch union may be conceived to confift of many parts 

 or fpaces moved through ; and perhaps even the 

 individual fibres of our mufcles have thus gradually 

 been brought to act in concert, which habits began 

 to be acquired as early as the very formation of the 

 moving organs, long before the nativity of the 

 animal \ as explained in the Se&ion XVI. 2. on in- 

 ftincl. 



F 2 a. There 



