INTRODUCTION. 



Amidst the fplrit of refearch and the general extenfion of knowledge, 

 which have diftinguiflied the prefent age, feme departments of fciencc 

 have not been cultivated as much as they deferve. The natural hiftory 

 of the mind and the philofophy of the paffions are, furely, objefts of tlie 

 utmoft moment to human happinefs ; and yet they have not been ftudied 

 in equal degree with the animal oeconomy of man, and other creatures, 

 or even with the nature and properties of the vegetable and mineral king- 

 doms ; although the materials and leading fafts, which might ferve to 

 found the conclufions of moral inveftigation are more numerous, more 

 faithfully detailed, and more methodically digefted, than the experiments 

 on which natural philofophers have built their theories. What is hiftory 

 but a colleftion of experiments in human conduft, or, in other words, 

 the natural details of moral agency ? and, in addition to the data, which 

 hifliory furniflies, without travelling abroad, without rifque, or expence, 

 every man has within himfelf an objeft of interefting inveftigation, and 

 the means of extending his knowledge of the moral part of human na- 

 ture, whereas an extended acquaintance with the animal, the vegetable, 

 or mineral kingdoms, requires diftant voyages, fatiguing journies, per- 

 fonal danger. 



The importance of a knowledge of the human mind, and of the fprings 

 and motives of moral agency may be elliraated, by the degree of fuccefs, 

 and fuperiority among men, which it ufually infures to the poffeflbr. 



Why 



