The subject matter of linguistics comprises all manifestations of human speech, whether that of savages or civilized nations, or of archaic, classical or decadent periods. In each period the linguist must consider not only correct speech and flowery language, but all other forms of expression as well. And that is not all: since he is often unable to observe speech directly, he must consider written texts, for only through them can he reach idioms that are remote in time or space.
The scope of linguistics should be:
a) to describe and trace the history of all observable languages, which amounts to tracing the history of families of languages and reconstructing as far as possible the mother language of each family;
b) to determine the forces that are permanently and universally at work in all languages, and to deduce the general laws to which all specific historical phenomena can be reduced; and
c) to delimit and define itself.
Linguistics is very closely related to other sciences that sometimes borrow from its data, sometimes supply it with data. The lines of demarcation do not always show up clearly. For instance, linguistics must be carefully distinguished from ethnography and prehistory, where language is used merely to document. It must also be set apart from anthropology, which studies man solely from the viewpoint of his species, for language is a social fact. But must linguistics then be combined with sociology? What are the relationships between linguistics and social psychology? Everything in language is basically psychological, including its material and mechanical manifestations, such as sound changes; and since linguistics provides social psychology with such valuable data, is it not part and parcel of this discipline? Here I shall raise many similar questions; later I shall treat them at greater length.
The ties between linguistics and the physiology of sounds are less difficult to untangle. The relation is unilateral in the sense that the study of languages exacts clarifications from the science of the physiology of sounds but furnishes none in return. In any event, the two disciplines cannot be confused. The thing that constitutes language is, as I shall show later, unrelated to the phonic character of the linguistic sign.
As for philology, we have already drawn the line: it is distinct from linguistics despite points of contact between the two sciences and mutual services that they render.
Finally, of what use is linguistics? Very few people have clear ideas on this point, and this is not the place to specify them. But it is evident, for instance, that linguistic questions interest all who work with texts-historians, philologists, etc. Still more obvious is the importance of linguistics to general culture : in the lives of individuals and societies, speech is more important than anything else. That linguistics should continue to be the prerogative of a few specialists would be unthinkable-everyone is concerned with it in one way or another. But-and this is a paradoxical consequence of the interest that is fixed on linguistics-there is no other field in which so many absurd notions, prejudices, mirages, and fictions have sprung up. From the psychological viewpoint these errors are of interest, but the task of the linguist is, above all else, to condemn them and to dispel them as best he can.