12 



that appear correct ; and such an examina- 

 tion, to which I now invite you, must be 

 allowed to he a proper exercise of intellect. 



Since thinking is inevitable, our chief 

 enquiry should be how we ought to 

 think or theorize ; and on this point New- 

 ton himself has condescended to instruct 

 us. Our theories, hypotheses, or opinions, 

 for to me all these words seem to refer to 

 one and the same act of the mind should 

 be verifiable or probable, and should ra- 

 tionally account for all the known phae- 

 nomena of the subject they pretend to ex- 

 plain; under which circumstances it is 

 allowable to maintain them as good, un- 

 til others more satisfactory be discovered. 

 No man who thus theorizes need feel 

 shame in this employment of his intellec 

 tual powers ; no man can feel arrogance, 

 for it is acknowledged that his theory is 

 but a probable and rational conjecture. 



