II.
More or less complex, modifiable and imperfect, all phenomena are subject to laws. It is the supreme principle, the “fundamental dogma” of science and of positive philosophy. Comte thus enunciates it: “All phenomena whatever, inorganic or organic, physical or moral, individual or social, are all subjected in a continuous manner to rigorously invariable laws.”[51]
Undoubtedly this principle is not yet extended, by the majority of minds, to all phenomena. This is shown clearly enough by their mode of reasoning in ethics and in politics. But it is, however, implied in their general conception of nature. It thus assumes a universal character, which has caused it to be regarded by many philosophers as an innate, or at least a primitive notion, in the human mind. According to Comte, this is erroneous. Like John Stuart Mill, whom he expressly quotes on this point,[52] he sees in this principle the result of a long, gradual induction, at the same time individual and collective. Except in the case of the most familiar phenomena, whose regularity is most striking, the human mind does not begin by believing in an invariable order. Even the mind’s conceptions, (theological and metaphysical), conceal the existence of laws, long after observation would have made it see them, were it freed from bias. It is true that the “first germs” of this principle exist as soon as human reason begins to be exercised, since the dominion of theological philosophy never could be absolute. But these germs are only developed very slowly, like the positive method and conceptions themselves.
The induction upon which this principle is founded only began to acquire solidity when it was definitely verified for a whole order of important phenomena, that is to say when mathematical astronomy had been founded. Phenomena of the highest importance, from the theoretical as well as from the practical point of view, could then be predicted with perfect certainty. The invariability of their laws had been placed beyond doubt. From that moment, the principle must have been extended by analogy, to the more complex orders of phenomena, even before their own laws could be known. But according to Comte this “vague logical anticipation” remained valueless and fruitless. It is of no use to conceive, in the abstract that a certain order of phenomena must be subject to laws. This empty conception cannot outweigh the theological and metaphysical beliefs, which have the force of habit in their favour. In order that the principle of laws should be really established in an order of phenomena, some laws must in fact have been discovered and demonstrated in it.
Consequently, while in the a priori doctrines the possibility of all science rests upon the principle of laws, in Comte’s doctrine, on the contrary, it is the progress of positive science which by degrees founds the principle, and which finally brings it to the universal form in which we find it to-day. Until the creation of sociology, this principle did not yet possess an effective universality, since the moral and social phenomena were not conceived as subject to invariable laws. But when the last conquest of the positive spirit is once accomplished, “this great principle at once acquires a decisive fulness, and may be formulated as applying universally to all phenomena.” Undoubtedly, in each order, we have only established for a few what henceforth we affirm for all phenomena without previous verification. But we think that laws, unknown to us, nevertheless exist. In this we yield to an “irresistible analogy,” which has never been proved to be false.
Thus, “the most fundamental dogma of the whole of positive philosophy, that is to say, the subjection of all real phenomena to invariable laws, only results with certainty from an immense induction, without really being deducible from any notion whatever.”[53] This immense induction is a progressive sum of inductions which have taken place successively in each category of phenomena. It would not be absurd, strictly speaking, that a certain category should not be submitted, like the others to invariable laws. But, since sociology has been founded, we know that all are in fact so subjected.
The laws are known to us, sometimes by experience, sometimes by reasoning. This diversity of origin in no way influences either the certainty or the philosophical dignity of the laws. Each of the six fundamental sciences gives examples of these two distinct modes of advance which mutually complete each other. “There is not less genius in the discovery of Kepler than in that of Newton. The initial laws of mechanics and even of geometry rest solely upon observation. The logical perfection consists in confirming by one of these ways what must have been found by the other. But one of the two suffices when all the conditions required by the method are fulfilled.”[54] How should the laws obtained by induction be regarded as less certain than the laws obtained by deduction, since the principle of laws itself rests upon an induction?