PREFACE. 



writers as free as poflible of reftraint ; that hu- 

 man liberty requires a reciprocity of opinion in 

 all things; that Nature feldom exhibits per- 

 fect models ; and that where the fund of dis- 

 cretion is over large, the quantum of honefly is 

 not always proportionate. 



I cannot help thinking it a queftion, much 

 more confequential to the good morals and well- 

 being of mankind, whether a writer has at- 

 tempted to controvert or obfcure a general 

 truth, than whether he has made free with this 

 fyflem, or that opinion, however, or by what- 

 foever authority, it may have been fan&ioned 

 and eftablifhed. 



After all, my mind is flill fenfible of an 

 anxiety, left my offering mould be unworthy 

 the public acceptance : here I will comfort 

 myfelf with the good old faw, which warrants, 

 that fomething is to be learned, even from the 

 raoft indifferent book ; and farther, that it is 

 fcarce poflible for a man tolerably acquainted 

 with his fubjecl;, to write feven or eight hundred 

 pages, without furnifhing hints adequate to the 

 value of fourteen millings, to a Reader inte- 

 refted therein. 



Sentences. 



