It would, of course, be absurd to imply that the mere bulk of the manuscripts preserved before the age of printing is a test of the value of an ancient author’s work; but, on the other hand, bearing in mind always the labour employed in the production of a single copy of a large work, it would be equally absurd to deny that the bulk of manuscripts has a certain bearing upon the value of the matter which they preserve. No doubt many a scribe would be deterred from starting out to copy manuscript by the great bulk of the work, and where he had no great preference, would be influenced by this alone to choose a smaller book. Again, doubtless many a scribe wearied of his task in the case of the more ponderous works, and gave it up after copying a few books. This common-sense explanation no doubt accounts for the fact that quite generally the earlier books rather than the later ones of works that have come down to us in a fragmentary condition are the ones preserved. Had Herodotus and Thucydides written forty books instead of eight or nine, it is very unlikely that even their genius would have sufficed to preserve the entire number. The case of Livy, whose work, despite the beauty of its style, has come down to us so sadly mutilated, sufficiently sustains this supposition. It is nothing against the merit of Diodorus, then, to reflect that half his work is lost; the wonder is rather that so much of it has been preserved. We have dwelt thus at length upon the work of Diodorus because it is a work that may be taken as in many ways representative of world histories in general. Certainly it was by far the greatest world history produced in antiquity, of the exact merits of which we have any present means of judging. Indeed, there is only one other world history that has come down to us, and this, the work of Justin, is in itself only an abridgment of the writing of another author, Trogus Pompeius. Considering when it was written, this work of Trogus, if we may judge from the abridgment, was an admirable production, and the abridgment itself is of great value in throwing light on some periods that otherwise are not well covered by extant documents. As a whole, however, it is a compendium of history rather than a comprehensive work like that of Diodorus. Of the works of the other world historians of antiquity it is impossible to speak with any measure of certainty. Polybius accredited Aphorus with being the only man who had written a world history before his day. It is known that Aphorus lived in the fifth century B.C., and that he was a fellow-pupil of another historian, Theopompus, in the famous school of Isocrates at Athens; but his work is only known to us through inadequate fragments and the indirect quotations of other authors. The same is true of the works of Theopompus just referred to, and of Timæus, another Greek whose writing had something of world historic comprehensiveness. But, even had these