The history of the origin of intellectual truth is undoubtedly made clearer by historical materialism, which aims at showing the influence of actual material conditions upon the opening out, and the very development of the human intellect. Thus the history of opinions, like that of science, needs to be for the most part re-written from this point of view. But those who, on account of such considerations concerning historical origins, return in triumph to the old relativity and scepticism, are confusing two quite distinct classes of problem. Geometry owes its origin no doubt to given conditions which are worth determining; but it does not follow that geometrical truth is something merely historical and relative. The warning seems superfluous, but even here misunderstandings are frequent and remarkable. Have I not read in some socialist author that Marx's _discoveries_ themselves are of merely historical _importance_ and must necessarily be _disowned_. I do not know what meaning this can have unless it has the very trivial one of a recognition of the limitation of all human work, or unless it resolves itself into the no less idle remark that Marx's thought is the offspring of his age. This onesided history is still more dangerous in reference to moral truth. The science of morality is evidently now in a transformation stage. The ethical imperative, whose classics are Kant's _Kritik der reinen Vernunft_, and Herbart's _Allgemeine praktische Philosophie_, appears no longer adequate. In addition to it an historical and a formal science of morality are making their appearance, which regard morality as a fact, and study its universal nature apart from all preoccupations as to creeds and rules. This tendency shows itself not only in socialistic circles, but also elsewhere, and it will be sufficient for me to refer to Simmel's clever writings. Labriola is thus justified in his defence of new methods of regarding morality. 'Ethics,--he says,--for us resolves itself into an historical study of the subjective and objective conditions according to which morality develops or finds hindrances to its development.' But he adds cautiously, 'in this way alone, _i.e._, within these limits, is there value in the statement that morality corresponds to the social situation, _i.e._, _in the final analysis_ to the economic conditions,' The question of the intrinsic and absolute worth of the moral ideal, of its reducibility or irreducibility to intellectual truth, remains untouched.