548 LOGIC OF THE MORAL SCIENCE . 



that a certain mode of action has been found by ourselves and 

 others to be well adapted to the cases of most common occur- 

 rence; so that if it be unsuitable to the case in hand, the 

 reason of its being so will be likely to arise from some un- 

 usual circumstance. 



4. The error is therefore apparent, of those who 

 would deduce the line of conduct proper to particular cases, 

 from supposed universal practical maxims ; overlooking the 

 necessity of constantly referring back to the principles of the 

 speculative science, in order to be sure of attaining even the 

 specific end which the rules have in view. How much greater 

 still, then, must the error be, of setting up such unbend- 

 ing principles, not merely as universal rules for attaining a 

 given end, but as rules of conduct generally ; without regard 

 to the possibility, not only that some modifying cause may 

 prevent the attainment of the given end by the means which 

 the rule prescribes, but that success itself may conflict with 

 some other end, which may possibly chance to be more 

 desirable. 



This is the habitual error of many of the political specu- 

 lators whom I have characterized as the geometrical school ; 

 especially in France, where ratiocination from rules of prac- 

 tice forms the staple commodity of journalism and political 

 oratory; a misapprehension of the functions of Deduction 

 which has brought much discredit, in the estimation of other 

 countries, upon the spirit of generalization so honourably 

 characteristic of the French mind. The common-places of 

 politics, in France, are large and sweeping practical maxims, 

 from which, as ultimate premises, men reason downwards to 

 particular applications, and this they call being logical and 

 consistent. For instance, they are perpetually arguing that 

 such and such a measure ought to be adopted, because it is a 

 consequence of the principle on which the form of government 

 is founded ; of the principle of legitimacy, or the principle of 

 the sovereignty of the people. To which it may be answered, 

 that if these be really practical principles, they must rest on 

 speculative grounds; the sovereignty of the people (for ex- 



