It is only tentative, and subject necessarily to frequent errors, for the elimination of which the severely skeptical spirit of the laws to which it is now held furnishes the best appliance. Modern science possesses an internal _vis medicatrix_ which prevents its suffering seriously from excesses or irregularities. When it ventures to touch the shield of the Unknowable, it is only with the butt of its lance, and the inevitable overthrow is accepted with the least modicum of humiliation. In that science which assumes to marshal all the others, philosophic and judicial history, ours ought to be the foremost age, if only because it has the aid of all the others. It does more, however, than they can be said to have contemplated. It widens the scope of history, and more precisely formalizes its functions. It makes of the old chroniclers so many moral statisticians, fully utilizing at the same time their services as collectors of material facts. The deductions thus arrived at it aims to test by the methods of the exact sciences. It invites, in a certain degree, moral philosophy to don the trammels of mathematics and decorate its shadowy shoulders with the substantial yoke of the calculus. Such is the programme of a school too young as yet to have matured its shape, but full of vigor and confidence, and a very promising outgrowth from the elder and more stately academy of abstract historical inquiry and generalization. The latter has redeveloped and freshened up for us the pictures of the ancient story-tellers, and has furthermore had them, so to speak, engraved and scattered among the people, until we have come to live in the midst of their times and enjoy an intimate knowledge of the actual condition of human polity and intelligence at any given period. Through the long gallery or the thick portfolio thus presented to our eye we may trace the common thread of motive under the varying conditions of time and circumstance. This thread able hands are aiding us to discover. To what segment of time shall we assign the name of Nineteenth Century? In A.D. 1800 there was dispute as to which was properly its first year, the question being settled in favor of 1801. Having thus struck out the first of the eighteen hundreds, we may take the liberty of similarly ostracizing the last twenty-four or twenty-five, which are yet to come, and start the nineteenth century as far back in the eighteenth. If we look farther behind us, the centuries will be found often to overlap in this way. Coming events cast their shadows before, and the morning twilight of the new age is refracted deeply into the sky of the old one. Of no case can this be more truly said than of that in point. Not only America, but Christendom, may safely date the century's commencement about 1775 or 1776. The narrowest isthmus between the mains of past and present will cover those years.