This is the way in which Comte enounces it, in the Plan des travaux scientifiques nécessaires pour réorganiser la société (1822).
“According to the very nature of the human intellect every branch of our knowledge must necessarily pass successively in the course of its progressive development, through three different theoretical states: the theological or fictitious state, the metaphysical or abstract state, finally the scientific or positive state.”[12]
In the first lesson of the Cours de philosophie positive, after having reproduced this statement, Comte adds: “In other words the human mind, by its nature, in each one of its researches makes use successively of three methods of philosophising, essentially different and even opposed to each other: firstly, the theological method, next, the metaphysical, and lastly the positive. Hence we find three kinds of philosophies, or general systems of conceptions of the totality of phenomena, which mutually exclude each other. The first is the necessary starting-point of human intelligence, the third, its fixed and final state; the second is solely destined to serve as a transition.”[13]
The words “theological” and “metaphysical” are here taken in a particular sense, strictly defined.
Comte calls “theology” a general system of conceptions concerning the universality of phenomena, which explains the appearance of these phenomena by the will of gods. He has not in his mind theological speculation as one usually understands it, as a rational or sacred science. He does not in the least dream of a study of revealed truth. He only designated by this name an interpretation of natural phenomena by means of supernatural and arbitrary causes. Theological—that is to say—fictitious. Elsewhere Comte calls this mode of explanation “imaginary” or “mythological.” It is in this sense that he could ask if each one of us did not remember having been in regard to his most important notions, a theologian in his infancy, a metaphysician in his youth, and a physicist in his manhood?[14] Comte does not allude to the religious traditions which the child receives from his parents, but indeed to the spontaneous tendency which causes him in the first place to explain natural phenomena by wills, and not by laws. Theology is here synonymous with anthropomorphism in the conception of causes.
Similarly Comte does not take the word “metaphysics” in the most usual extension of its meaning. The science of Being as such, the science of Substance or of first Principles, is not here in question, at least directly. He only refers to a certain mode of explaining phenomena given in our experience. For example, in physics, the hypothesis of an ether to explain optical and electrical phenomena is metaphysical. So it is in physiology with the hypothesis of a vital principle, or, in psychology, with the hypothesis of a soul. “Metaphysical or abstract,” says Comte. At bottom this mode of explanation is no other than the preceding one, but more and more pale and colourless, vanishing, so to speak, as natural phenomena, better observed, are referred no longer to capricious wills, but to invariable laws.
Let us then be careful not to give here to the words “metaphysics” and “theology” their full meaning. For instance, to conclude from the law of the three States that the evolution of humanity ever carries it further from theology, to end in a final state wherein religion should have no place is singularly to misapprehend Comte’s doctrine. On the contrary the evolution of humanity is leading it to a state which will be pre-eminently religious. In it religion will regulate the whole life of man. Comte perhaps would not refuse to define man, as has often been done, as a religious animal. The history of humanity may be represented, in a sense, as an evolution which proceeds from primitive religion (fetichism) to final religion (positivism). But the object of the law of the three States is not to express the religious evolution of humanity. It is only concerned with the progress of the human intellect. It sets forth the successive philosophies which that intelligence has been obliged by turn to adopt in the interpretation of natural phenomena. It is, in a word, the general law of the evolution of thought.
Those who made a mistake about it probably only considered this law in the first lesson of the Cours, where it is separately presented. But the error is no longer possible when one refers to the fourth volume of the Cours, where the law is put in its place, in social dynamics, especially in the fifty-eighth lesson, in the sixth volume.
It is not, however, without reason that Comte set forth this law in the first pages of his Cours de philosophie positive. In sociology as he conceives it, the law of the intellectual evolution of humanity, that is to say the law of the three States is the essential law of dynamics, and therefore of the whole of social science. For, of all the social factors of which the concomitant and joint evolution constitutes the progress of humanity, the intellectual factor is the most important. It is the dominant one, in the sense that the others depend far more upon it than it does upon them. The history of art, of institutions, of morals, of law, of civilisation in general could not be understood without the history of intellectual evolution, that is to say of science and of philosophy, whereas this one, strictly speaking, would still be intelligible without the others. This evolution is therefore the principal axis around which the other series of social phenomena are arranged. Thus the law which expresses it is the most “fundamental,” the most “general,” in the precise sense in which Comte understands this word. In enunciating this law he declares legitimate by anticipation the existence of a social science. He proves ipso facto not only that it is possible, but that it already exists. Hence the eminent position which he gives to the law of the three states.