This philosophy was contained in his _Cours de Philosophie positive_ (1830-1842), which he regarded as the theoretic basis of a reforming political philosophy. One of the most interesting aspects of this work, however, is its claim to be a positive _philosophy_. Had not Comte accepted the Saint-Simonist doctrine of a belief in science as the great future power in society? How then comes it that he gives us a “_philosophie_ positive” in the first place and not, as we might expect, a “_science_ positive”? Comte’s answer to this is that science, no less than society itself, is disordered and stands in need of organisation. The sciences have proceeded to work in a piecemeal fashion and are unable to present us with _une vue d’ensemble_. It is the rôle of philosophy to work upon the data presented by the various sciences and, without going beyond these data, to arrange them and give us an organic unity of thought, a synthesis, which shall produce order in the mind of man and subsequently in human society. The precise part to be played by philosophy is determined by the existing state of scientific knowledge in the various departments and so depends upon the general stage of intelligence which humanity has reached. The intellectual development of humanity was formulated generally by Comte in what is known as “The Law of the Three Stages,” probably that part of his doctrine which is best known and which is most obvious. “The Law of the Three Stages” merely sets down the fact that in the race and in the individual we find three successive stages, under which conceptions are formed differently. The first is the theological or fictitious stage, in which the explanation of things is referred to the operations of divine agency. The second is the metaphysical or abstract stage when, for divinities, abstract principles are substituted. In the third, the scientific or positive stage, the human mind has passed beyond a belief in divine agencies or metaphysical abstractions to a rational study of the effective laws of phenomena. The human spirit here encounters the real, but it abstains from pretensions to absolute knowledge; it does not theorise about the beginning or the end of the universe or, indeed, its absolute nature; it takes only into consideration facts within human knowledge. Comte laid great emphasis upon the necessity of recognising the relativity of all things. All is relative; this is the one absolute principle. Our knowledge, he insisted (especially in his _Discours sur l’Esprit positif_, 1844, which forms a valuable introduction to his thought as expressed in his larger works), is entirely relative to our organisation and our situation. Relativity, however, does not imply uncertainty. Our knowledge is indeed relative and never absolute, but it grows to a greater accord with reality. It is this passion for “accord with reality” which is characteristic of the scientific or positivist spirit.