NATURAL THEOLOGY. 213 



ment before, does not support the column. In 

 cases also of extreme weakness, the patient cannot 

 stand upright. Secondly, that these actions are 

 only in a small degree voluntary. A man is sel- 

 dom conscious of his voluntary powers in keeping 

 himself upon his legs. A child learning to walk 

 is the greatest posture-master in the world : but 

 art, if it may be so called, sinks into habit ; and 

 he is soon able to poise himself in a great variety 

 of attitudes, without being sensible either of cau- 

 tion or effort. But still there must be an aptitude 

 of parts, upon which habit can thus attach ; a pre- 

 vious capacity of motions which the animal is thus 

 taught to exercise : and the facility with which 

 this exercise is acquired forms one object of our 

 admiration. What parts are principally employed, 

 or in what manner each contibutes to its office, 

 is, as hath already been confessed, difficult to ex- 

 plain. Perhaps the obscure motion of the bones 

 of the feet may have their share in this effect. 

 They are put in action by every slip or vacillation 

 of the body, and seem to assist in restoring its 

 balance. Certain it is, that this circumstance in 

 the structure of the foot, viz., its being composed 

 of many small bones, applied to and articulating 

 with one another by diversely shaped surfaces, 

 instead of being made of one piece, like the last 

 of a shoe, is very remarkable. 



