iqi ANTIENT METAPHYSICS. Book XL 



Further, the force exerted by mind^ in the animal body, Is fuch as 

 is Impoffible to be exerted by any material caule operating in fo fmall 

 a fpace ; for the bones of any animal that raifes a weight, are fo ma- 

 ny levers which the mufcles move by the means of the finews. For 

 example, when a man raifes and holds out any weight with his ex- 

 tended arm, the bone of his arm below the elbow is the lever ; the 

 fulcrum, or center of motion, is the joint of the elbow; and ih^ poivcr 

 operates by (inews or tendons inferied into the bone below the elbow, 

 and near to It ; which fmews are moved by a great mufcle above the 

 elbow : The lever, therefore, here, is one of that kind where the pouuer 

 has the difadvantage ; for the learned in mechanics know, that there 

 are three kinds ot levers, in two of which the/>ow^r has the advantage, 

 that is, a poiver of lefs mafs or quantity of matter will move a weight 

 of greater : But, in the lever of the third kind, \.hc pouuer acting be- 

 twixt the fulcrum and the weight, the ponver has the difadvantage, and 

 therefore mufi: be a greater quantity of matter than the weight. Now, 

 the human arm Is a lever of this kind, and \}[\z poiver of this lever has 

 the greater difadvantage, that it Is very near the fulcrum, and at a 

 great diftance from the weight ; in fo much, that Borelli * has Ihown, 

 that, in order to fupport a pound weight, which a man holds out with 

 his extended arm, there muft be, by the laws of mechanifm, a force of 

 70,000 pounds. Now, a ftrong man can hold out in his hand two 

 f^ones, which, according to this calculation, will require 2l poiver to 

 raife it, by a lever of fuch a conlfrudion, ot no lels than 140,000 

 flones. So great a poiver^ exerted by mind In fo fmall a fpace as the 

 human body, may, i think, enable us to form fome conception how 

 fuperior minds, in the great expanfe of heaven, may move thofe vaft 

 bodies with fuch incredible celerity. What the machinery may be 

 there, we cannot tell ; but the fame ingenious author has demon- 

 ftrated, that, if the animal machinery were fo contrived, as to give the 

 poijuer all the advantage that it commonly has in machines of human 

 invention, not only the animal would be monilroufly deformed, but 



incapable 



* Borelli de Motu ^nimaliunu 



