312 ELEMENTS OF SCIENCE 



A suspected cause may be tested by allowing it to 

 operate in circumstances of less complication, to see 

 whether the effect will still be produced. 



Such are the main practical rules which should be 

 made use of when applying the inductive method in 

 practice. 



The chief part of logic, however, is the deductive 

 system (the elements of which have been described in 

 this chapter), which therefore, as before said, especially 

 constitutes both the science of the laws of thought, and 

 the art of reasoning. 



