Literature, which is of later development as at present used, comprises those subjects which have a relation to human life and human nature through the power of the imagination and the fancy. Technically, literature includes _history, poetry, oratory, the drama_, and _works of fiction_, and critical productions upon any of these as themes. Such, at least, will be a sufficiently exact division for our purpose, although the student will find them overlapping each other's domain occasionally, interchanging functions, and reciprocally serving for each other's advantage. Thus it is no confusion of terms to speak of the poetry of science and of the science of poetry; and thus the great functions of the human mind, although scientifically distinct, co-operate in harmonious and reciprocal relations in their diverse and manifold productions. ENGLISH LITERATURE.--English Literature may then be considered as comprising the progressive productions of the English mind in the paths of imagination and taste, and is to be studied in the works of the poets, historians, dramatists, essayists, and romancers--a long line of brilliant names from the origin of the language to the present day. To the general reader all that is profitable in this study dates from the appearance of Chaucer, who has been justly styled the Father of English Poetry; and Chaucer even requires a glossary, as a considerable portion of his vocabulary has become obsolete and much of it has been modified; but for the student of English literature, who wishes to understand its philosophy and its historic relations, it becomes necessary to ascend to a more remote period, in order to find the origin of the language in which Chaucer wrote, and the effect produced upon him by any antecedent literary works, in the root-languages from which the English has sprung. GENERAL PRINCIPLE.--It may be stated, as a general principle, that to understand a nation's literature, we must study the history of the people and of their language; the geography of the countries from which they came, as well as that in which they live; the concurrent historic causes which have conspired to form and influence the literature. We shall find, as we advance in this study, that the life and literature of a people are reciprocally reflective. I. CELTS AND CYMRY.--Thus, in undertaking the study of English literature, we must begin with the history of the Celts and Cymry, the first inhabitants of the British Islands of whom we have any record, who had come from Asia in the first great wave of western migration; a rude, aboriginal people, whose languages, at the beginning of the Christian era, were included in one family, the _Celtic_, comprising the _British_ or _Cambrian_, and the _Gadhelic_ classes. In process of time these were subdivided thus: