. 225. THEORY OF THE SYSTEM. 333 



gree of resemblance itself. On this account it becomes im- 

 possible to express this resemblance by the agreement in 

 one or a certain number of characters. This does not, 

 however, prevent the application of the idea of the ge- 

 nus to the natural productions altogether ; for this appli- 

 cation does not pre-suppose the idea to be limited to 

 single characters; but it allows, and even requires, to 

 preserve it in its full generality. The genera being thus 

 founded upon the resemblance of the species, as is already 

 demonstrated in Zoology and Botany, render all the ser. 

 vices which Natural History possibly may expect ; and the 

 same will be likewise confirmed by their introduction in fu- 

 ture in Mineralogy. 



The natural-historical idea of the genus is peculiar to 

 Natural History, and is solely intended for the purpose of 

 promoting that science. Hence the natural-historical ge- 

 nera must not be compared with ideas of this kind other- 

 wise determined ; not even with those of the same deno- 

 mination, Avhich have been hitherto applied in Minera- 

 logy. For, the establishment of these genera is founded in 

 part upon determinative reasons, foreign to Natural His- 

 tory ; so that the inferences drawn from them must be in- 

 consistent with the principles of that science, even though 

 it were demonstrated that in every case they correspond 

 to the natural-historical resemblance. Other sciences must 

 consider the natural-historical genus in the same point of 

 view. In a chemical system of minerals, the genus must 

 have a chemical foundation. It is not necessary that it 

 should agree with the genus in Natural History ; though 

 the species, determined according to chemical ideas in the 

 one, and according to natural-historical ideas in the other 

 science, must be identical in both (. 220.). The method 

 of connecting several points of view into a single one, does 

 not promote the sciences, and gives full scope to all sorts 

 of hypotheses. Different sciences, which refer to the same 

 subject, must follow without deviation the course deter- 

 mined by their peculiar principles, or they will cease to be 

 different sciences. Their way will finally converge in one 



