. 218. THEORY OF THE SYSTEM. 319 



tity as the fundamental individual, and which therefore 

 exactly agree in respect to this idea, although they are 

 not absolutely identical. It is indifferent which of the 

 simple forms we may ascribe to the one or to the other ; 

 and thus we may arbitrarily exchange these forms with each 

 other^ without in the least altering any thing in respect to that 

 relation. Two or more of these individuals become abso- 

 lutely identical (. 214.), if we suppose them to possess one 

 and the same form. Herein consists the process by which, 

 under the supposed circumstances, individuals, though not 

 absolutely identical, may yet be brought under the idea 

 of identity. 



If, on the contrary, a number of different individuals is 

 given, agreeing in every natural-historical property except 

 the forms of crystallisation, and if these forms are mem- 

 bers of the same series, we are entitled to consider all 

 those individuals as a single one, whose form is a combina- 

 tion of the different simple forms of the single individuals, 

 with which the rest of the properties exactly agree. The 

 individual in the compound form is identical with itself, and 

 the single individuals contained in it will consequently be 

 in an exactly similar relation to the idea of identity. 

 This proves that by the above mentioned process, that is to 

 say, by substituting one form instead of the other, they 

 may be collected under the idea of identity. 



In order to explain this by an example, let us suppose a 

 crystal of octahedral Fluor-haloide to possess the form of 

 a hexahedron. If we substitute the octahedron in its stead, 

 the relation of the individual to the idea of identity is 

 not altered, because the two forms, the hexahedron and 

 the octahedron, are members of the same series of crystal- 

 lisation. Notwithstanding this and other similar substitu- 

 tions, the individual does not cease to be octahedral Fluor- 

 haloide. But if, instead of the hexahedron, we suppose a 

 rhombohedron, or any other form not belonging to the 

 tessular system, to take the place of the hexahedron, the 

 relation of the individual to the idea of identity is indeed 

 altered, and it can no longer be maintained that the indivi- 



