162 Mr WEDGWOOD, ON THE KNOWLEDGE 



breathing goes on as well whether I think of it or no, yet whenever my attention is directed to 

 the question, I am internally conscious of the exertion, while the action of my heart lies wholly 

 without the sphere of my effort. But in our experiment the muscular exertion though 

 instinctive is undoubtedly the act of the infant himself, and therefore must under some aspect 

 or another come within the grasp of his intelligence. The experience however of the resisted 

 exertion cannot at once give rise to the notion of resistance to motion, because the infant has 

 as yet no knowledge of the bodily existence of his hand, and no intention of setting such an 

 organ in motion. It seems to me that the effect of the entire action in his intelligence will be 

 the direct apprehension of that which we understand by the term body, a complex object, con- 

 sisting of surface (undeveloped as yet in form and magnitude), apprehensible by touch, and 

 substance, revealed by resistance to muscular exertion, furnishing a new type of being essentially 

 different from any of the five fundamental kinds with which the infant is hitherto acquainted. 



The muscular power exerted by the infant in closing his hand on our finger, being 

 instinctively guided by the sense of touch, his attention will be directed by the joint exercise 

 of the faculties to a single object, which will appear as solid in virtue of the resistance it 

 opposes to muscular exertion, while the impression it makes on the organ of external Touch 

 will give it a definite place in the material world. 



The apprehension of bodily substance as a direct and elementary operation of the intelli- 

 gence was correctly referred by Locke to the exertion of muscular power, although he failed to 

 distinguish the latter as a perceptive faculty from the passive sense of touch. " If any one 

 ask me," he says, [n. 4. $ 6.] " what this solidity" [or bodily substance] " is, I send him to his 

 senses to inform him. Let him put a flint or a football between his hands and then endeavour 

 to join them, and he will know. If he thinks this not a sufficient explication of solidity, what 

 it is and wherein it consists ; I promise to tell him when he tells me what thinking is or 

 wherein it consists." 



When I press my hand against the table I feel the solid substance of which it consists as 

 a positive object of thought, as completely independent of any logical reference to the motion 

 of my hand prevented from taking place by the interposition of the table, as is the thought of 

 colour or of sound of any logical reference to the mechanism of the eye or the ear. In the 

 latter case the affection of the eye or the ear by the luminous or aerial undulations is physiolo- 

 gically instrumental in the act of sight or of hearing, and precisely in the same way it appears 

 to me that the resisted exertion of muscular power under the guidance of external touch is 

 physiologically instrumental in the apprehension of bodily substance. The difference is that in 

 the former case the organic condition instrumental in the display of the phenomenon is depend- 

 ent upon forces external to the percipient being, of the action of which he has no immediate 

 consciousness, while it consists in the latter case in the exertion of his own muscular power by 

 the percipient himself. Seeing then that the percipient is necessarily cognisant of the physical 

 means employed in the apprehension of body, it was an easy error to suppose that the thought 

 of the means was an essential element in the thought of the object apprehended — the thought 

 of the resisted movement of the hand in the conception of the resisting object. But if it be 

 true that the connexion between the pressure of my hand against the table and the information 

 of a solid obstacle thereby obtained is analogous to the connexion between the physical 



