Musing upon the structural foundations of his biosemiotic worldview, biosemiotics founder Thomas A. Sebeok once remarked, more seriously than not, "I consider myself a Thomist – a René Thomist, that is' (1991: 157). Given that Sebeok – a self-described biologist manqué, a professional linguist, and a committed interdisciplinarian in many ways, but in no sense a mathematician – would claim such intellectual affinity with a man whose life's work revolved around differential equations and topological geometry may seem to call out for explanation for some readers, as may the inclusion of mathematician René Thom in this book. Those with acquainted with Thom's writings, or with the history of biosemiotics, however, will understand at once Thom's place in this anthology of biosemiotic writings, and why Sebeok regarded "the semiotic intimations of the French polymath René Thom as nuggets of pure gold [and as] pointers towards the elevation of the doctrine of signs to the status of a theory or a science" (1979: viii).