Outline of an Explanatory Account of Cladistic Practice

A naturalistic account of the strengths and limitations of cladistic practice is offered. The success of cladistics is claimed to be largely rooted in the parsimony-implementing congruence test. Cladists may use the congruence test to iteratively refine assessments of homology, and thereby increase the odds of reliable phylogenetic inference under parsimony. This explanation challenges alternative views which tend to ignore the effects of parsimony on the process of character individuation in systematics. In a related theme, the concept of homeostatic property cluster natural kinds is used to explain why cladistics is well suited to provide a traditional, verbal reference system for the evolutionary properties of species and clades. The advantages of more explicitly probabilistic approaches to phylogenetic inference appear to manifest themselves in situations where evolutionary homeostasis has for the most part broken down, and predictive classifications are no longer possible.