On distinction of species

We can only partition biological organisms into species by distinguishing (ie, defining) the class (ie, the concept) species. Now, distinguishing classes, like species, do we, however, perform by distinguishing both some similarity between the entities in the class and some difference between this class and other classes of such entities at the same time. By this, we contrast the new class against its opposite class as being both dissimilar and different.

The problem concerning the class species is what the opposite class possibly can be? Which class can we contrast species against? The answer is that we can only contrast it against the class entity, meaning that one of them excludes the other per definition, ie, that we can't acknowledge both of them at the same time, because they are not just dissimilar, but moreover different. The class species is thus consistent only if the class entity isn't, and vice versa.

This fact explains our extreme problems to define the class species. These classificatory (ie, conceptual) problems may we confuse with the (then apparently factual) problem that reality consists of a vast variety of life forms, but these two kinds of problems (ie, conceptual and real) are actually just two facets of one and the same problem, that is, that not both species and entity can be consistent at the same time. Solution of these problems does thus not hinge on whether they are abstract or real; we can't distinguish both species and entity consistently at the same time independently of which.

The distinction of species is thus doomed to fail by being inconsistent per definition. The problem of distinguishing species, which cladistics thinks it has overcomed, thus still remains. Cladistics thus still lacks the fundament it needs to turn rational to irrational, and vice versa.The concept species still lacks a consistent definition.