Biological systematics faces a fundamental choice:
- that kinds are real, or
- that kinds are not real.
If it assumes that kinds are real, then the logical action is to search for “the tree of life”, whereas if it assumes that kinds aren’t real, then the logical action is to find an agreement on an orthogonal classification like the Linnean system.
The problem with this choice is that the first assumption, ie, that kinds are real, is inconsistent, meaning that there is no solution (ie, no “tree of life”), whereas the second assumption, ie, that kinds aren’t real, is consistent, meaning that there are many solutions.
The fundamental choice is thus in practice between whether to search for something that isn’t to be found or for an agreement on an orthogonal classification like the Linnean system, that is, between an endless search for something that isn’t to be found or for an agreement that can’t be reached.
This fundamental choice means that biological systematics can never become anything more than an agreement. This fact, in turn, means that it will rotate around different solutions, like fashion, forever. Many words, but no solution, per definition.
(It is good to understand the conditions to avoid wasting time on impossibilities.)