in science passes out of its originally passive state, and is employed for reaching other previsions, it passes from theory into practice—­becomes science in action—­becomes art.  And when we thus see how purely conventional is the ordinary distinction, how impossible it is to make any real separation—­when we see not only that science and art were originally one; that the arts have perpetually assisted each other; that there has been a constant reciprocation of aid between the sciences and arts; but that the sciences act as arts to each other, and that the established part of each science becomes an art to the growing part—­when we recognise the closeness of these associations, we shall the more clearly perceive that as the connection of the arts with each other has been ever becoming more intimate; as the help given by sciences to arts and by arts to sciences, has been age by age increasing; so the interdependence of the sciences themselves has been ever growing greater, their mutual relations more involved, their consensus more active.

* * * * *

In here ending our sketch of the Genesis of Science, we are conscious of having done the subject but scant justice.  Two difficulties have stood in our way:  one, the having to touch on so many points in such small space; the other, the necessity of treating in serial arrangement a process which is not serial—­a difficulty which must ever attend all attempts to delineate processes of development, whatever their special nature.  Add to which, that to present in anything like completeness and proportion, even the outlines of so vast and complex a history, demands years of study.  Nevertheless, we believe that the evidence which has been assigned suffices to substantiate the leading propositions with which we set out.  Inquiry into the first stages of science confirms the conclusion which we drew from the analysis of science as now existing, that it is not distinct from common knowledge, but an outgrowth from it—­an extension of the perception by means of the reason.

That which we further found by analysis to form the more specific characteristic of scientific previsions, as contrasted with the previsions of uncultured intelligence—­their quantitativeness—­we also see to have been the characteristic alike in the initial steps in science, and of all the steps succeeding them.  The facts and admissions cited in disproof of the assertion that the sciences follow one another, both logically and historically, in the order of their decreasing generality, have been enforced by the sundry instances we have met with, in which the more general or abstract sciences have been advanced only at the instigation of the more special or concrete—­instances serving to show that a more general science as much owes its progress to the presentation of new problems by a more special science, as the more special science owes its progress to the solutions which the more general science is thus led to attempt—­instances therefore illustrating the position that scientific advance is as much from the special to the general as from the general to the special.