In true Cartesian fashion, he demonstrates why this Light must have its locus within the soul and not in some external means or medium. All knowledge that God is being revealed in external signs, or through external means, already presupposes a prior knowledge of God. We can judge no doctrine, no Book to be Divine except by some inward and immediate knowledge of what really is Divine. Without this Light the Scriptures are only Words and Letters. But "if we experience that the Book called the Bible in regard to the Divine doctrine therein comprised hath such a harmony with That [in us] by which God is known, that He must needs have been the Author of it, there cannot rationally be any more powerful demonstration."[35] The same principle is true with regard to every conceivable form of revelation which could be made to our outward senses, whether by words, or by miracles, or by any other visible "operations." No finite thing can bring us a knowledge of God unless we already have within us a sufficient knowledge of Him to make us able to appreciate and judge the Divine character of the particular revelation; that is to say, we must already have God in order either to seek Him or to find Him; or, as Balling puts it, "Unless the knowledge of God precedes, no man can discern Him." God is, therefore, the prius of all knowledge: "The knowledge of God must first be, before there can be knowledge of any particular things,"[36] and God must be assumed as present in the soul before any basis of truth or of religion can be found. "The Light is the first Principle of Religion; for, seeing there can be no true Religion without the knowledge of God, and no knowledge of God without this Light, Religion must necessarily have this Light for its first Principle."[37] "Without thyself, O Man," he concludes, "thou hast no {131} means to look for, by which thou mayest know God. Thou must abide within thyself; to the Light that is in thee thou must turn thee; there thou wilt find it and nowhere else. God is nearest unto thee and to every man. He that goes forth of himself to any creature, thereby to know God, departs from God. God is nearer unto every man than himself, because He penetrates the most inward and intimate parts of man and is the Life of the inmost spirit. Mind, therefore, the Light that is in thee."[38]