It would seem, then, that not only philosophical, but absolutely every higher species of knowledge is an internal science of experience. For the formal science of mathematics is not a positive science for the cognition of a real object, so much as an organon and aid for other sciences, which, however, as such, is both excellent in itself, and admits of many useful applications. We may, therefore, on this hypothesis consider each of these four faculties of man, which I have called the principal poles or leading branches of human consciousness, as a peculiar sense for a particular domain of truth. For all experience and all science thereof rests on some cognitive sense as the organ of its immediate perceptions. Now, the reason, which, in its form of conscience, announces itself as an internal sense of right and wrong, is, as the faculty for the development and communication of thought, usually named the common sense. It constitutes the bond of connection between men and their thoughts, which is dependent on and conditioned by language and its organ, and may be called the sense for all that is distinctively human. In this respect it forms the foundation and first grade of all other senses for, and immediate organs of, a higher knowledge. Fancy, again, being itself but a reflection of life and of the living powers of the natural world, is the inward sense for nature, which, as will hereafter be more fully shown, first lends and assures to natural science its due import and true living significance. And, inasmuch as the perfect intellection of a single object results from the totality alone--the significance and spirit of the whole--therefore the understanding is the sense for that mind [_geist_] which manifests itself in the sensible world, whether this be a human or natural, or the supreme Divine intelligence.
Now, if we may venture to consider the fourfold revelation of God in conscience, in nature, in Holy Writ, and the world's history, as so many living springs or fertilizing streams of a higher truth, we must suppose the existence of a good soil to receive the water of life and the good seed of divine knowledge. For without an organ of susceptibility for good to receive the divine gift from above, no amount of revelation would benefit man. Now, the soul, so susceptible of good on all sides, both from within and from without, is even this organ for the reception of revelation. And this function of the soul, together with its creation of language as the outer form of human knowledge, constitutes its contribution to science, and especially to internal science. And even with the understanding, as the sense which discerns the meaning and purport of revelation, the soul is co-operative--since nothing divine can be understood merely in the idea, and of and by itself alone, but in every case a feeling for it must have preceded, or, at least, contributed toward its complete understanding. The soul, consequently, which is thus susceptible of the divine, is ever informing itself about, or co-operating in the acquisition of a knowledge of the Godlike. And this, the soul's love and pursuit of divine truth, when, unfolding itself in thought, it comes forth in an investiture of words, is even philosophy--not, indeed, the dead sophistic of the schools, but one which, as it is a philosophy of life, can be nothing less than living. And the soul, thus ardently yearning for the divine, and both receiving and faithfully maintaining the revealed Word, is the common center toward which all the four springs of life and streams of truth converge. In free meditation it reconciles and combines them.