But both in this and the other departments of his work, we are bound to estimate Hume, as we do great workmen in all departments of mental labour, not by the state of his science at the present day, but by that in which he found it. To comprehend how far it may be practicable for any one mind to create a full and satisfactory history of the island of Great Britain, without having the advantage of the previous labours of many minds, occupied in elucidating the details of the various branches of knowledge with which he has to deal, let us cast a casual glance at the prominent topics which must be fully discussed in such a History, if it be a satisfactory work. The historian should be master of every scrap of information contained in Greek or Roman authors, about the connexion of the people of the ancient world with our island. In the works of Cæsar and Tacitus this will be a simple matter; but scattered about among the productions of the Panegyrists, and in other such obscure quarters, there are many important incidental notices, which will not be so easily found or so satisfactorily interpreted. To this the investigator must add more recondite stores of knowledge, collected from etymological investigations among the roots of languages--Celtic and Teutonic. He must study Strabo, Ptolemy, and the other geographers; and interpreting the information collected from them, and the incidents derived from the other sources above alluded to, with his etymological inquiries, he must endeavour to solve the vexed questions about the migration of races--whether the Cimbri were pure Celts? whether the Welsh are the descendants of that race? whether the Caledonii, with whom Agricola fought, were Celts? who and what were those mysterious people, called the Picts? There must be some criticism, however unsatisfactory it may be, on the worship anterior to the introduction of Christianity, and on the vestiges of that and of other early customs supposed to be supplied by the remnants of ancient masonry and engineering, with which our island abounds. The historian must next be able to show what is truly known, and what is not, regarding the inroads of the Teutonic tribes, and must be able to fathom the learning of the German antiquaries on this department of history. Here the early literature of Ireland, of which so much has lately been printed by O'Conor and others, and the relics of Scandinavian metrical histories, will widen the inquiry, while they render it more satisfactory. Having got these settlers from the Teutonic tribes, the Saxons as they are generally called, established in the island, the peculiar internal policy, national character, and literature of Britain, begin to assume a shape under the eye of the historian, and to gather round them their distinctive attributes as he proceeds. He will soon have to deal with the birth of laws and customs, which, modelled to the progress of an increasing population and civilisation, are still in daily practice.