Thus it is that the _written_ records of distant ages, with the knowledge of which the intellectual, moral, and political well-being of mankind is inseparably connected, are secured from extinction by a mode of conservation that is less liable to extensive hazards than any other that can be imagined. If Man be cut off from the knowledge of the past, he becomes indifferent to the future, and thenceforward sinks into the rudeness and ferocity of the sensual life. The redundant amplitude, therefore, of the means by which this knowledge is preserved, only bears a due proportion to the importance of the consequences that depend upon its perpetuation. CHAPTER X. SEVERAL METHODS AVAILABLE FOR ASCERTAINING THE CREDIBILITY OF ANCIENT HISTORICAL WORKS. The facts referred to in the preceding chapters belong in common to ancient books of all classes, and they tend to prove that the works of the Greek and Roman writers--poets, dramatists, philosophers, critics, and historians--which issued from the press in the fifteenth and sixteenth centuries, may, by means of various and independent evidence, be infallibly traced up to the age in which they are commonly supposed to have been written. The reader’s attention is now to be directed to one class of those ancient works, namely, those which are professedly historical; and our object will be to ascertain on what grounds, and with what limitations, such works deserve our confidence as truthful narratives of facts. The very same mode of inquiry which common sense suggests, on the most ordinary occasions, when we are called upon to estimate the value of testimony, is applicable to all cases of the like nature. Nor can the importance of the consequences that may be involved in the issue of the investigation, in a peculiar instance, render it invalid, or warrant our rejection of it as unsatisfactory. In some lesser particulars the modes of estimating oral and written testimony must differ; but in substance the heads of inquiry will be the same. In the case with which we have now to do--namely, the credibility of the testimony of ancient historians, it is natural to consider the following points:-- 1. The moral and intellectual character of the writer,--if this can be known; 2. The means of information he possessed; 3. The time and circumstances of the first publication of the work; 4. The exceptions it may be necessary to make to his testimony on particular points; arising either from the peculiar nature of the facts affirmed, or from the apparent influence of prejudice--personal, or national; and-- 5. The agreement of the narrative in question with evidence derived from other, and independent sources. In judging then of the authenticity of an historical work we have, in the first place, to form an estimate of the writer’s moral and intellectual character and qualifications; supposing that the means of forming an opinion on these points are within our reach.