Yet not altogether; for in the natural order, too, we have the phenomenon of instinct to consider--both spiritual and animal. Giving heredity all the credit we can for storing up accumulated experience in the nervous system of each species, there remains a host of fundamental animal instincts which that law is quite inadequate to explain; those, for example, which govern the multiplication of the species and secure the conditions under which alone heredity can work. Such cannot be at once the effect and the essential condition of heredity; and yet they are, of all instincts, the most complex and mysterious. Indeed, it seems more scientific to ascribe other instincts to the same known and indubitable, if mysterious, cause, than to seek explanation in causes less known and more hypothetical. In the case of many instincts, it would seem that the craving for the object precedes the distinct cognition of it; that the object is only ascertained when, after various tentative gropings, it is stumbled upon, almost, it might seem, by chance. And this seems true, also, of some of our fundamental spiritual instincts; for example, that craving of the mind for an unified experience, which is at the root of all mental activity, and whose object is ever approached yet never attained; or, again, there is the social and political instinct, which has not yet formed a distinct and satisfying conception of what it would be at. Or nearer still to our theme, is the natural religious instinct which seeks interpretations and explanatory hypotheses in the various man-made religions of the race, and which finds itself satisfied and transcended by the Christian revelation. In these and like instances, we find will-movements not caused by the subjects' own cognitions and perceptions, but contrariwise, giving birth to cognitions, setting the mind to work to interpret the said movements, and to seek out their satisfying objects.