CLASSIFICATION AND THE PKEDICABLES. 169 



completed. Man, therefore, we may be permitted 

 to call a species ; Christian, or Mathematician, we 

 cannot. 



Note here, that it is by no means intended to 

 imply that there may not be different Kinds, or logical 

 species, of man. The various races and tempera- 

 ments, the two sexes, and even the various ages, may 

 be differences of kind, within our meaning of the 

 term. I say, they may be ; I do not say, they are. 

 For in the progress of physiology it may be made out, 

 that the differences which distinguish different races, 

 sexes, &c., from one another, follow as consequences, 

 under laws of nature, from some one or a few primary 

 differences which can be precisely determined, and 

 which, as the phrase is, account for all the rest. If 

 this be so, these are not distinctions in kind ; no more 

 than Christian, Jew, Mussulman, and Pagan, a differ- 

 ence which also carries many consequences along 

 with it. And in this way classes are often mistaken 

 for real kinds, which are afterwards proved not to be 

 so. But if it shall turn out, that the differences are 

 not capable of being accounted for, then man and 

 woman, Caucasian, Mongolian, and Negro, &c., are 

 really different Kinds of human beings, and entitled to 

 be ranked as species by the logician ; though not by 

 the naturalist. For (as already hinted) the word 

 species is used in a very different signification in logic 

 and in natural history. By the naturalist, organized 

 beings are never said to be of different species, if it is 

 supposed that they could possibly have descended 

 from the same stock. That, however, is a sense 

 artificially given to the word, for the technical pur- 

 poses of a particular science. To the logician,, if a 

 negro and a white man differ in the same manner, 

 (however less in degree) as a horse and a camel do, 



