INTRODUCTION. 



" IN entering upon any scientific pursuit," says Sir John 

 Herschel, " one of the student's first endeavours ought to be 

 to prepare his mind for the reception of truth, by dismissing, 

 or at least loosening, his hold on all such crude and hastily 

 adopted notions respecting the objects and relations he is 

 about to examine, as may tend to embarrass or mislead him 5 

 and to strengthen himself by something of an effort and a 

 resolve, for the unprejudiced admission of any conclusion which 

 shall appear to be supported by careful observation and logical 

 argument, even should it prove of a nature adverse to notions 

 he may have previously formed for himself, or taken up, 

 without examination, on the credit of others. Such an effort 

 is, in fact, a commencement of that intellectual discipline 

 which forms one of the most important ends of all science. 

 It is the first movement of approach towards that state of 

 mental purity which alone can fit us for a full and steady 

 perception of moral beauty as well as physical adaptation. 

 It is the 'euphrasy and rue' with which we must ( purge our 

 sight,' before we can receive and contemplate as they are the 

 lineaments of truth and Nature." 



