This book examines the relationship between classification and evolutionary theory, with reference to the competing schools of taxonomic thinking. Emphasis is placed on one of these schools, the transformed cladists, who have attempted to reject all evolutionary thinking in classification and to cast doubt on evolution in general. The author examines the limits to this line of thought from a philosophical and methodological perspective rather than from a biological viewpoint. He concludes that transformed cladistics does not achieve what it claims and that it either implicity assumes a Platonic World View, or is unintelligible without taking into account evolutionary processes - the very processes it claims to reject. Through this analysis the author attempts to formulate criteria, of an objective and consistent nature, that can be used to judge competing methodologies and theories without resorting to any particular theoretical standpoint for justification. Philosophers of science, zoologists interested in taxonomy and evolutionary biologists will find this a compelling study of an area of biological thought that has recently been attracting a great deal of attention.