He had now published the whole of that department of his History, from which his opinions on the later progress of the British constitution can be derived; and the epoch of this publication calls for some notice of the manner in which subsequent inquirers have found that he performed his task.[65:3] He was not like such writers as Clarendon and Brady, the interested or prejudiced advocate of the crown against the people; and we must look for the causes of his erroneous views in what he did not know, or did not believe, rather than in what he wilfully misrepresented. In his "Essay on Commerce," published in 1752, we find him thus foreshadowing the principle on which he was to treat the History of Britain:--"Lord Bacon, accounting for the great advantages obtained by the English in their wars with France, ascribes them chiefly to the superior ease and plenty of the common people among the former; _yet the government of the two kingdoms was at that time pretty much alike_." This assertion has been satisfactorily proved to be erroneous. The spirit of credulity in historical inquiry makes out every thing ancient to be better and greater than its modern representative. The spirit of scepticism questions whatever is said in favour of antiquity. The sceptic cannot throw doubt on the existing wonders of modern times. If one nation is far beyond another in arts, arms, civilization, or wealth, the facts cannot be denied; but when he looks back into past ages, the pliability of the evidence admits the influence of the levelling principle of scepticism, the tendency of which is to make all mankind seem much alike; and Hume, who would not have ventured to say that in his own day the constitutions of France and England were very much alike, considered it but a piece of proper caution to discard as fallacious the evidence that there was any great difference between them in former times. Unquestionably the doubting or inquiring spirit is a valuable quality in a historian; for the narratives of human affairs are full of falsehoods, which it is the philosophical historian's function to discard. But the sifting will not be satisfactory, if the materials subjected to it have not been largely and laboriously collected; and the charge against Hume is, that he applied it to imperfect data. Where the data are insufficient, credulity and scepticism are merely the counterparts of each other, and produce erroneous results nearly alike. Those who proclaimed Bruce, the Abyssinian traveller, to be a liar, for statements which have now been authenticated, believed in the account given of a fictitious people, in an impudent forgery, called Psalmanazer's Formosa, which would not now impose for a moment on any educated person. Our enlarged knowledge of the matters to be subjected to sceptical analysis, has now, in both cases, brought us to the right conclusion.