ON NOSOLOGY. 445 



the summit of human knowledge in every part of science, and 

 requires not only the clearest but the most comprehensive views, 

 such as, with respect to diseases, we can arrive at only by often- 

 repeated exercises and much study. The attempt may at first 

 appear uncouth and difficult, but by repetition it will become 

 more familiar and easy, and you must be content to make such 

 a progress. When, a little more than thirty years ago, I first 

 got a sight of the botanical system of Linnaeus, it appeared to 

 me to be a piece of the most uncouth jargon and minute pe- 

 dantry ; but, by length of time, it is now as familiar to me as 

 my mother tongue : and with whatever difficulty it was first 

 received in most parts of Europe, it has now surmounted these, 

 and its utility has reconciled every person to the study of it. 



I might begin by giving a general idea of what we call method, 

 and illustrate it by examples taken from Natural History ; but 

 I cannot suppose this necessary. Natural history, in which 

 method is so generally applied, is now so universally studied, 

 and there is such a propensity to it among all ranks of men, 

 and all kinds of students over the whole of Europe, that to 

 give an account of it here to gentlemen advanced in their 

 several studies, would be equaUy absurd and unnecessary. I 

 can hardly think it necessary even to take much pains in illus- 

 trating the necessity of this study in general, and in pointing 

 out to you that it is applicable to a certain length in every part 

 of science, when we aim at an accurate distinction of one thing 

 from another : it has been long ago established in logic, that 

 nothing is distinguished, till it is distinguished by its genus 

 and species. I hardly think it necessary to inform you, that 

 it is impossible to convey any accurate knowledge of things 

 from one country to another, or from one age to another, with- 

 out more or less of this method ; and it is certain that we have 

 lost much of the knowledge which the ancients had acquired in 

 the animal, vegetable, and fossil kingdoms, because they wanted 

 the means of conveying it by those proper characters which 

 method only teaches; but this is an accident which, we can plainly 

 perceive, will not happen to learning again, as long as this me- 

 thodical distribution is anywhere cultivated among men. In 

 the last ^place, I hardly think it necessary to speak of the neces- 

 sity of method in order to the investigation of the productions 



