A fatal and very common error is that of judging the actions of the past by the moral standard of our own age. This is especially the error of novices in history and of those who without any wide and general culture devote themselves exclusively to a single period. While the primary and essential elements of right and wrong remain unchanged, nothing is more certain than that the standard or ideal of duty is continually altering. A very humane man in another age may have done things which would now be regarded as atrociously barbarous. A very virtuous man may have done things which would now indicate extreme profligacy. We seldom indeed make sufficient allowance for the degree in which the judgments and dispositions of even the best man are coloured by the moral tone of the time or society in which they live. And what is true of individuals is equally true of nations. In order to judge equitably the legislation of any people, we must always consider corresponding contemporary legislations and ideas. When this is neglected our judgments of the past become wholly false. How often, for example, has such a subject as the history of the penal laws against Irish Catholics been treated without the smallest reference to the contemporary laws against Protestants that existed in every Catholic nation and the contemporary laws against Catholics that existed in almost every Protestant country in Europe. How often have the English commercial restrictions on the American colonies been treated as if they were instances of extreme and exceptional tyranny, while a more extended knowledge would show that they were simply the expression of ideas of commercial policy and about the relation of dependencies to the mother-country which then almost universally prevailed.