The emergence of Transformational Generative Grammar (TGG) in the 1950s is an event in the history of linguistics that has been recounted many times, in many different ways, by many different people, and since this book is primarily concerned with the development of TGG, some sort of apologia is required in order to justify retelling the same story yet again. Accordingly, it is hoped that this introduction will provide the requisite justification, and, in summary explanation, it can be stated at the outset that the main motivation for the particular narration offered here is dissatisfaction – specifically, dissatisfaction stemming from the conviction that none of the existing versions of the TGG narrative provide sufficient information concerning the influence of contemporaneous advances in the formal sciences upon the development of linguistic theory in the twentieth century. If indeed it is the case that this aspect of TGG history has been neglected in the past, then this neglect is certainly surprising, since the earliest proponents of TGG have never disguised the fact that the theory derived considerable inspiration from the formal sciences. For instance, in 1995 (to consider just one example) Chomsky stated explicitly that ‘[g]enerative grammar can be regarded as a kind of confluence of long-forgotten concerns of the study of language and mind, and new understanding provided by the formal sciences’ (Chomsky 1995: 4), and the scientific nature of TGG itself has often been noted over the years.