416 INDUCTION. 



universe at any particular moment is impossible, but would 

 also be useless. In making chemical experiments, we do not 

 think it necessary to note the position of the planets ; because 

 experience has shown, as a very superficial experience is suffi 

 cient to show, that in such cases that circumstance is not 

 material to the result: and, accordingly, in the ages when 

 men believed in the occult influences of the heavenly bodies, 

 it might have been unphilosophical to omit ascertaining the 

 precise condition of those bodies at the moment of the experi 

 ment. As to the degree of minuteness of the mental sub 

 division ; if we were obliged to break down what we observe 

 into its very simplest elements, that is, literally into single 

 facts, it would be difficult to say where we should find them : 

 we can hardly ever affirm that our divisions of any kind have 

 reached the ultimate unit. But this too is fortunately un 

 necessary. The only object of the mental separation is to 

 suggest the requisite physical separation, so that we may 

 either accomplish it ourselves, or seek for it in nature ; and 

 we have done enough when we have carried the subdivision as 

 far as the point at which we are able to see what observations 

 or experiments we require. It is only essential, at whatever 

 point our mental decomposition of facts may for the present 

 have stopped, that we should hold ourselves ready and able to 

 carry it farther as occasion requires, and should not allow the 

 freedom of our discriminating faculty to be imprisoned by the 

 swathes and bands of ordinary classification ; as was the case 

 with all early speculative inquirers, not excepting the Greeks, 

 to whom it seldom occurred that what was called by one 

 abstract name might, in reality, be several phenomena, or that 

 there was a possibility of decomposing the facts of the universe 

 into any elements but those which ordinary language already 

 recognised. 



2. The different antecedents and consequents, being, 

 then, supposed to be, so far as the case requires, ascertained 

 and discriminated from one another ; we are to inquire which 

 is connected with which. In every instance which comes 

 under our observation, there are many antecedents and many 



