In controversies relating to progress it is asked whether the work of man be fertile or sterile, whether it be lost or preserved, whether history have an end, and if so of what sort, whether this end be attainable in time or only in the infinite, whether history be progress or regress, or an interchange between progress and regress, greatness and decadence, whether good or evil prevail in it, and the like. When these questions have been considered with a little attention we shall see that they resolve themselves substantially into three points: the conception of development, that of end, and that of value. That is to say, they are concerned with the whole of reality, and with history only when it is precisely the whole of reality. For this reason they do not belong to supposed particular sciences, to the philosophy of history, or to sociology, but to philosophy and to history in so far as it is philosophy. When the ordinary current terminology has been translated into philosophical terms it calls forth immediately the thesis, antithesis, and synthesis by means of which those problems have been thought and solved during the course of philosophy, to which the reader desirous of instruction must be referred. We can only mention here that the conception of reality as development is nothing but the synthesis of the two one-sided opposites, consisting of permanency without change and of change without permanency, of an identity without diversity and of a diversity without identity, for development is a perpetual surpassing, which is at the same time a perpetual conservation. From this point of view one of the conceptions that has had the greatest vogue in historical books, that of _historical circles,_ is revealed as an equivocal attempt to issue forth from a double one-sidedness and a falling back into it, owing to an equivocation. Because either the series of circles is conceived as composed of identicals and we have only permanency, or it is conceived as of things diverse and we have only change. But if, on the contrary, we conceive it as circularity that is perpetually identical and at the same time perpetually diverse, in this sense it coincides with the conception of development itself.