483 M)'. BiciiENO on St/f,tcms and Methods 



and producing by certain laws of generation others like itself: 

 whereas all that logicians have meant, is a number of objects 

 bearing a certain resemblance to one another, and on that ac- 

 count denominated by a single appellation, which may be em- 

 ployed to express any one of them. This term is the creature 

 of art, to help us up the first step of generalization. By its as- 

 sistance we propose to reason upon all the individuals conform- 

 ing to the law we have laid down, as safely as we can do of any 

 one of them. There is this inconvenience attending; the use 

 of it by naturalists, that it assumes as a fact, that which in the 

 present state of science is in many cases a fit subject of in- 

 quiry; namely, that species, according to our definition, do exist 

 throughout nature. It is too convenient a term to be dispensed 

 with, even as an assumption ; only care should be taken that 

 we do not accept the abstract term for the fact. 



It might, for instance, be proposed as a legitimate question, 

 whether the species of some familiar genera, such as Rosa, 

 Riibiis, Saxifraga, do not run into one another by imperceptible 

 shades, unappreciable by human sense, in the same manner as 

 certain genera melt and intermingle their characters, so as to 

 render it impossible to circumscribe them. Indeed, the extent 

 to which species-making has been carried in modern times, al- 

 most leads to this conclusion. Visible and palpable distinctions 

 are in many cases no longer relied on ; and there are many acute 

 naturalists, who, without bringing the subject to the test of experi- 

 ment, are content to rely on those empirical characters, which can 

 only be perceived by long and familiar experience, and cannot 

 be described by words. 'I'he truth is, that all sensible objects 

 have characters which leave impressions upon the mind, without 

 our being capable of embodying them in language. ^Ve are all 

 aware of this when we speak of tastes, and tints, and the counte- 

 nances of our friends. Every-body perceives them, yet nobody 



can 



