FLEXIBILITY AND ELASTICITY. 261 



and as it is generally used at this day, we must 

 conclude that it is not only retained within the 

 narrow limits to which the fibres are confined, 

 but that it is never exerted without the inter- 

 vention of an external power impressed upon it. 

 Elasticity consequently consists of two proper- 

 ties ; of weakness and of power, of passion 

 and of action, of suffering to be, and of becom- 

 ing to be, of flexibility through the agency of an 

 external force, and secondly, of re-action from 

 internal and inherent construction ; as when 

 Shakspeare says, " when splitting winds make 

 flexible the knees of knotted oaks ;" the split- 

 ting winds constitute the external cause, by 

 which the flexible knees of knotted oaks were 

 made to bend. Such, however, is the internal 

 construction of the fibres of which the oak is 

 composed, that they are able to return back to 

 their original state, as soon as the splitting 

 winds have ceased to rage. It is this dead 

 capacity of being acted upon, and of being 

 changed without the power of resisting action, 

 of being moved without the power of moving 

 itself, of being modelled without the power of 

 modellingitself, which constitutes the mobility 

 of LOCKE, the vis inertia of NEWTON, the flexi- 

 bility and elasticity of our modern philosophers.* 



* This capacity to be acted upon is proved in a manner the 

 most decisive, by the commutation total and complete which 



