THE CHEMICAL METHOD. 547 



must have been learned by deduction from the prin- 

 ciples of human nature; experience being called in 

 only as a supplementary resource, to determine the 

 causes which produced an unexplained residue. But 

 if the principles of human nature may be had recourse 

 to for the establishment of some political truths, they 

 may for all. If it be admissible to say, England must 

 have prospered by reason of her prohibitory system, 

 because after allowing for all the other tendencies 

 which have been operating, there is a portion of 

 prosperity still to be accounted for; it must be admis- 

 sible to go to the same source for the effect of the 

 prohibitory system, and examine what account the 

 laws of human motives and actions will enable us to 

 give of its tendencies. Nor, in fact, will the experimental 

 argument amount to anything, except in verification 

 of a conclusion drawn from those general laws. For 

 we may subtract the effect of one, two, three, or four 

 causes, but we shall never succeed in subtracting the 

 effect of all causes except one; while it would be a 

 curious instance of the dangers of too much caution, 

 if, to avoid depending on a priori reasoning concerning 

 the effect of a single cause, we should oblige our- 

 selves to depend upon as many separate a priori rea- 

 sonings as there are causes operating concurrently 

 with that particular cause in some given instance. 



| We have now sufficiently characterized the absurd 

 misconception of the mode of investigation proper to 

 political phenomena, which I have termed the Che- 

 mical Method.^ So lengthened a discussion would not 

 have been necessary, if the claim to decide authori- 

 tatively on political doctrines were confined to persons 

 who had competently studied any one of the higher 

 departments of physical science. But since the gene- 

 rality of those who reason on political subjects, satis- 



2 N 2 



