Natural Classification
Natural classification is based on the natural characters of the taxa. Some consider natural classification a phylogenetic one reflecting the evolutionary relationships among the groups that comprise it. Some oppose this concept on the ground that phylogeny is not known but merely hypothesised. It is not an attribute but only a guess at an attribute and it is based on previous classification. The animals are placed into as many groups and subgroups as are the similarities and dissimilarities. They define "natural classification" as one in which the groups are recognised by having a maximum number of attributes in common, wit11 their limits set by discontinuities in the diversity, and capable of yielding the maximum number of correct deductions about correlations of other features.