This paper focuses on the applicability of paradigm to derivational morphology and the pressure of paradigm enforced on derivational phonology and morphology. Through a close examination of well-attested data, we will demonstrate that apparent surface idiosyncrasies in phonology are the results of paradigm leveling, and that paradigmatic forces of analogy are productively operating in English word formation. On the basis of these observations, it can be argued that the notion of paradigm has at least some justification within derivational morphology as well, even if not to the same extent that it has with inflectional morphology and that the paradigm forces are independently needed in any adequate phonological and morphological theory. This can also be extended to provide evidence against the split morphology hypothesis that inflectional and derivational morphology belong to different grammatical modules.