PHILOSOPHY OF NATURE LEIBNITZ'S IDEAS. 59 



mg of mass multiplied by momentum, and active force as 

 the product mv* of mass multiplied by the square of the 

 velocity. Let us in the first place remark how highly un- 

 philosophical it is to regard the most simple and irredu- 

 cible things in the" world as products, to confine within the 

 strict limits of a one-term statement the living pulsations 

 of the infinite and the absolute in things. In the next 

 place, the attempt to define force by any calculation of 

 figures seems like aping a man who should insist that the 

 arrow-marks used in geometrical diagrams to denote the 

 direction of forces were exact likenesses of the forces 

 themselves. The cipher is the sign of quantity, the line 

 that of motion. Force is something else than quantity, a 

 very different thing from motion. But let us grant these 

 definitions are proper : the question still remains, What are 

 the causes that produce acceleration, velocity, resistance, 

 in the mass ? Now, it is impossible to avoid connecting 

 these causes with some principle higher than geometries, 

 with a spontaneity more or less resembling that effort 

 which in ourselves goes before action. We are thus al- 

 ways brought back, whether we would or not, to active 

 monads, whose infinite varieties, infinite relations, and in- 

 finite interminglings, bring forth all. The accomplished 

 writers we speak of will in vain strive to reduce to measured 

 fractions of space and of time that which is in its essence 

 the opposite of space and time force ; and the attempt is 

 futile to prove that we have not a consciousness of the 

 dynamic resistance of the elements of the world as clear 

 as that which we have of our own individual effort to 

 counterpoise it. 



It is easy to point out the cause of such specious abuse 

 of geometrical and mechanical considerations in natural 

 philosophy. It grows out of ignorance of those biological 

 facts by which the profound spontaneity, and the reality 

 of forces consubstantial with bodies, are revealed in a 



