Thus, the statical analysis establishes the laws of coexistence, the dynamic analysis the laws of succession or of movement. The principle of the conditions of existence is nothing else than _the direct and general conception of the necessary harmony of these two analyses, that is to say, of the agreement of these two orders of laws_.[65] If this harmony, in fact, was not realised, no living being, no natural system of phenomena could subsist. From the point of view of the object this principle accounts for the permanence of beings: from the point of view of the subject it expresses the possibility of science. Why does Comte say that the importance and fertility of this principle are far superior to those of the doctrine of final causes? It is because this latter doctrine claims to “explain.” In referring the natural order to the wisdom of a Providence, it dispenses in some measure with scientific research, or at least it does not require it. The principle of the conditions of existence, on the contrary, is closely allied to the positive conception of natural phenomena. It only implies the existence of laws. It only establishes the continuity of the relations between these laws, a continuity verified by experience, since beings subsist and reproduce themselves. In a word, it allows us to connect the laws of succession with the laws of coexistence everywhere. Now, to connect is the essential function of science. By means of this principle not only the successive moments of any natural evolution whatever are understood as having solidarity with each other but the whole of this evolution becomes intelligible by its relation to the statical conditions to which it corresponds. And, in virtue of the relativity of science, or, if we prefer it, of the universal reciprocal action of all phenomena, the principle of the conditions of existence leads the human mind to a scientific investigation ever more exact and never completed.