448 INTRODUCTORY LECTURES. 



eases ; I expect that nobody will refuse that we can go a certain 

 length in this ; and certainly no objection can be urged against 

 going a certain length though we can go no farther ; but how 

 far we can go, nobody will say till he has tried. 



Within these hundred years some of the most experienced 

 men in natural history, and particularly in botany, for instance 

 Mr. Ray, imagined when a methodical arrangement was first pro- 

 posed to them, that it was impossible; and Mr. Ray's first attempts 

 were extremely feeble ; but every body will now readily ac- 

 knowledge, that they have truly gone a great deal farther, than 

 was, not long ago, thought possible ; and I know that within 

 these fifty years some of the most considerable botanists still 

 thought that the classification and distribution of plants was a 

 pure fancy. But these difficulties with respect to natural his- 

 tory are now entirely removed, and so they ought to be with 

 respect to Nosology. The principal objection is derived from 

 the imperfection of the trials that have actually been made ; and 

 I must own that our nosologists have begun at the wrong end. 

 Their first attempt was to form the classes and orders with 

 which they began their system, whereby they have made very 

 odd work ; and they do, to be sure, associate diseases that are 

 in themselves very dissimilar, and separate many that are near- 

 ly related. We may take for an example of this the most syste- 

 matic author in Europe, the celebrated Linnaeus. It appears 

 to every body else extremely ridiculous when he arranges sy- 

 philis among fevers, merely from the circumstance of their being 

 both contagious ; and when he separates diseases so nearly related 

 as the gout and rheumatism, especially the last, from other in- 

 flammatory diseases ; and indeed many similar absurdities oc- 

 cur in his system. But it will be plain that this is not the fault 

 of method in general ; it is a fault arising from this, that nosol- 

 ogists have been more studious of the general system than of 

 particulars ; and this is a mistake which we must be liable to, 

 till every species has been fully taken notice of. 



I am so far from thinking that we ought to enter anxiously into 

 the general systematic arrangement, that in my prolegomena I 

 have insinuated a contrary notion. Because I think there is use 

 in making the attempt, I have with others attempted to form 

 classes and orders ; but for the accuracy of these I would by 



