Although human beings have changed a great deal in social conditions over the last two thousand years, they are recognisably the same species, and it is therefore plausible to assume that their linguistic behaviour, like their physiology, is in general terms governed by the same principles. This is not to argue, however, that historical linguistics simply entails the transfer to past linguistic states of methodologies appropriate to investigations of present-day language. Historians as a professional body are always fascinated by the detail of the events which they discuss; and there are good reasons for this practice, for data from the past do not come to us directly. Texts are never simply illustrative of past states of the language, for every text has a special context which conditions its contents. Thus in an historical study such as this book it is important from the outset to face up to some of the problems with which texts confront us-problems which vary diachronically. It is necessary, in other words, to examine the nature of the evidence for the history of English from various stages in that history; and this chapter demonstrates some typical evidential problems from the three stages of the language conventionally distinguished: Old, Middle and Modern English. (The theoretical problems involved in using the present to explain the past are dealt with much more profoundly than is possible here in Labov 1994, passim.)
Before doing so, however, it must be noted that such a linking of textual analysis to more general linguistic concerns is not a feature of scholarly practice which has been invariably accepted by all linguistic historians. Since the end of the Second World War, two traditions of enquiry into the history of English can be distinguished: the 'philological' and the 'linguistic'. These traditions have from time to time been seen as mutually antagonistic, although there are signs that a scholarly rapprochement between them is beginning to emerge.