LAW OF CAUSATION. 413 



problem of Induction ; and is one of those questions, 

 the principles of the solution of which will, it is to be 

 hoped, result from the inquiry we have undertaken. 



$ 6. Does a cause always stand with its effect in 

 the relation of antecedent and consequent ? Do we 

 not often say of two simultaneous facts that they are 

 cause and effect as when we say that fire is the 

 cause of warmth, the sun and moisture the cause of 

 vegetation, and the like ? It is certain that a cause 

 does not necessarily perish because its effect has been 

 produced ; the two, therefore, do very generally 

 coexist ; and there are some appearances, and some 

 common expressions, seeming to imply not only that 

 causes may, but that they must, be contemporaneous 

 with their effects. Cessante causa, cessat et effectus, 

 has been a dogma of the schools : the necessity for 

 the continued existence of the cause in order to the 

 continuance of the effect, seems to have been once a 

 general doctrine among philosophers. Mr. Whewell 

 observes that Kepler's numerous attempts to account 

 for the motion of the heavenly bodies on mechanical 

 principles, were rendered abortive by his always sup- 

 posing that the force which set those bodies in motion 

 must continue to operate in order to keep up the 

 motion which it at first produced. Yet there were at 

 all times many familiar instances in open contradiction 

 to this supposed axiom. A coup de soleil gives a man 

 a brain fever : will the fever go off as soon as he is 

 moved out of the sunshine ? A sword is run through 

 his body : must the sword remain in his body in order 

 that he may continue dead? A ploughshare once 

 made, remains a ploughshare, without any continuance 

 of heating and hammering, and even after the man 

 who heated and hammered it has been gathered to his 



