Argues that ontogenetic and phylogenetic theories are related and that such a coupling can be established only in reference to a metatheory. The metatheory is construed in terms of a combination of logical coherence and requirements necessary for generalization as well as comprehensive, philosophical representations of living beings (e.g.,…

Argues for unifying the conceptual frameworks of theories of evolution so that problems and their solutions in one theory may be transposed and explored in the others. The argument is used to reconsider the mutationist and Darwinian theories of evolution in the light of Piaget's nonstandard theory of evolution. (Author/RH)

Discusses the conditions for validating customary phylogenetic procedures. Concludes that the requisites of homogeneity and completeness for proved short lineages seem satisfied by the Hennigian but not the Haeckelian procedure. The epistemological antinomy of the two procedures is emphasized for the first time. (Author/RH)