Profoundly concerned with the properties of access, perceptual complexity, and pragmatic presuppositions, here formalized as a calculus of markedness, this study attempts to provide a highly principled explanation of morphological complexity and change. Here, markedness is construed as a qualitative statement, as a natural parametric device, and not as an empirically empty algorithmic tool. This work is fundamentally concerned with iconicity as a property of grammatical encoding. A major contribution to a dynamic theory of language as a communicative endeavor, this study is strongly oriented towards universals with prognostic capacity. Moreover, the terms morphology and naturalness are here given biological reference, keyed as they are to the basis for a biology of language, and it is thus altogether fitting that this first English-language version of a work that has long enjoyed critical airing in Europe be prefaced with an essay by none less than Rupert Riedl -- Back cover.