Descartes's subjectivism is a transitory phase leading from the authoritative objectivism of the middle ages to the critical objectivism of modern times. The authoritative philosophy of the Schoolmen yielded to the arbitrary philosophy of metaphysical subjectivity, commencing as a matter of principle with doubt, instead of commencing with positive data, and establishing anarchy through lack of any objective method of arriving at truth. The reaction against the arbitrary authority of scholasticism was indispensable to further progress. But we must not rest satisfied with its negative result. We cannot commence a business without capital and without making a start. So we cannot begin philosophy with nothing. Knowledge is not possible without positive facts to serve as a basis to stand upon. The negative features of Descartes's philosophy naturally found their ultimate completion in agnosticism. The assumption of the existence of a subject led to the doctrine, that this subject is unknowable. Moreover, the assumption of something that underlies the acts of thought leads to the assumption of something that underlies objective existence, and thus it begets the theory of things in themselves. This theory involves us in innumerable contradictions and thus it ends ultimately in the proposition that things in themselves are unknowable. There are few who know the historical meaning of agnosticism; but those who can survey philosophical thought in its evolution, its growth, and decay, know that agnosticism means failure in philosophy. The word is a foreign-sounding name for "knownothingism," denoting a half-concealed confession of bankruptcy. The philosophy of the future, in order to escape from the fatal consequences of agnosticism, has to discard the subject-superstition inherited from Descartes. Descartes was a great thinker, a star of first magnitude in the realm of thought, but it is time that, without returning to the authoritative philosophy of the Schoolmen, we should free ourselves from the errors of his one-sided subjectivism. Let us not forget, that all subjective states contain an objective element. Objectivity is no chimera, and we are very well enabled to establish the truth or untruth of objective facts. The philosophy of the future, accordingly, will be a philosophy of facts, it will be _positivism_; and in so far as a unitary systematisation of facts is the aim and ideal of all science, it will be MONISM.