But in each case besides the practical need, which bids us consume the substance as dead matter, and apply it to use, there is the theoretical bent which seeks to reproduce ideally the past as a living and fully developed organism. 'This past,' says Hegel, 'is traversed by the individual, in the same way as one who begins to study a more advanced science repeats the preliminary lessons with which he had long been acquainted, in order to bring their information once more before his mind. He recalls them: but his interest and study are devoted to other things. In the same way the individual must go through all that is contained in the several stages in the growth of the universal mind: but all the while he feels that they are forms of which the mind has divested itself,--that they are steps on a road which has been long ago completed and levelled. Thus, points of learning, which in former times tasked the mature intellects of men, are now reduced to the level of exercises, lessons, and even games of boyhood: and in the progress of the schoolroom we may recognise the course of the education of the world, drawn, as it were, in shadowy outline[2].' The scope of historical investigation therefore is this. It shows how every shading in the present world of thought, which makes our spiritual environment, has been once living and actual with an independent being of its own. But it also reveals the presence of shades and elements in the present which if our eyes had looked on the present alone we should scarcely have suspected: and it thus enables us to interpolate stages in development of which the result preserves only rudimentary traces. And, when carried out in a philosophical spirit, it shows further, that in those formations, which are produced in each period of the structural development of reason, the universe of thought, or the Idea, is always whole and complete, but characterised in some special mode which for that period seems absolute and final. Each form or 'dimension' of thought, in which the totality is grasped and unified, is therefore not so simple or elementary as it may seem to casual observers regarding only the simplicity of language: it is a total, embracing more or less of simpler elements, each of which was once an inferior total, though in this larger sphere they are reduced to unity. Thus each term or period in the process is really an individualised whole, with a complex interconnexion and contrast included in it: it is _concrete._ No single word or phrase explains it: yet it is one totality,--a rounded life, from which its several spheres of life must be explained. But when that period is passing away, the form of its idea is separated, and retained, apart from the life and mass of the elements which constituted it a real totality; and then the mere shading or shell, with only part of its context of thought, is left _abstract._ When that time has come, a special form, a whole act