846. For it is the number of a man. That this signifies its nature, as if it were from the understanding of truths, which understanding the men of the church ought to possess, is evident from the signification of number, as denoting the nature of faith (concerning which see above, n. 841); and from the signification of man, as denoting the understanding of truth which the men of the church have in matters of faith (concerning which also see above, n. 280, 546, 547). In this case, as if it were from such understanding. For faith separated from the life is a belief in what is false, consequently destitute of truth and the understanding of it. The case, therefore, is the same here with the signification of man, as with that of wisdom above (n. 844); by which is meant, as if it were wisdom, although it is insanity.
 Moreover those who are in faith separated from charity prohibit the use of the understanding, insisting upon obedience to a faith not understood, and that a faith understood is a man's own faith, and therefore natural and not spiritual. But what is the nature of intellectual faith shall be told.
The Word in its spiritual sense treats, in many passages, of the understanding of the Divine truth in the Word; and, where the desolation of the church is treated of, it also treats of the destruction of the understanding of the Divine verities thereof from the Word. And from the spiritual sense of passages upon that subject taken collectively, and carefully investigated, it is evident, that in the measure that the understanding of truth perishes in the church, in the same measure the church perishes. The understanding of the Word is also signified in many passages by Egypt, Ashur, Israel, and also by Ephraim - by Egypt, the natural understanding thereof; by Ashur, rational understanding; by Israel, spiritual understanding; and by Ephraim, the actual understanding of the Word in the church. But these three degrees of understanding - the natural, rational, and spiritual, ought to be one, in order that a man may from enlightenment see and perceive the genuine truths of the Word. For the natural understanding, which is the lowest, cannot be enlightened by its own light (lumen), but it must be enlightened by the light of the rational man, which is in the midst, and the latter from spiritual light. For the spiritual understanding is in the light of heaven, and sees by virtue of it; and the Rational is a medium between the Spiritual and the Natural, and receives spiritual light, which it transmits to the Natural and enlightens it. It is therefore evident that the natural understanding without light through the Rational from what is spiritual, is not understanding, for it is without light from heaven; and the truths of the church, which are also the truths of heaven, can be seen only in the light of heaven. The reason is, that Divine truth going forth from the Lord as a Sun, is the light of heaven; and the Lord by His own light, which is spiritual light, alone enlightens man.
 From these things it is evident, that the Lord desires a man not only to know the truths of the church to which he belongs, but also to understand them, not, however, from natural light separated from spiritual light; for natural light separated from spiritual light, in heavenly or spiritual things, is not light but darkness. For a man, from natural light separated from spiritual light, views the things of the church from himself, and not from the Lord. Therefore he can see them only from appearances and fallacies, and to see the former from the point of view of the latter, is to see falsities instead of truths, and evils instead of goods. The fire which sends forth and also enkindles that light is the love of self, and the pride of one's own intelligence therefrom. In the measure that a man, thinking from that fire and its light, excels in ingenuity, and has the power to confirm everything he pleases thence, in the same measure, he can also confirm falsities and evils, to such a degree as even to make them appear to be truths and goods. Indeed, he can show falsities and evils in a brilliant natural light, which is, nevertheless, a delusive light, increased by the contriver. But to comprehend the things of the church from this light is not to understand, but rather to misunderstand them. For a man from that light alone sees truths as falsities, and falsities as truths. This is especially the case when some accepted dogma is assumed as the truth itself, without previous investigation as to whether it be true or not, and if it is investigated it is only by statements confirmed by reasonings from the natural man, or by confirmation from passages from the Word that are not understood. When a man views all the dogmas of his religion in this way, he may assume as a principle whatever he pleases, and shed upon it the light of confirmation to such a degree as to make it to appear to be truth from heaven, although it is falsehood from hell.
 From what has been said, it may be concluded that by understanding the truths of the church is meant the understanding of them when illuminated by the light of heaven, thus by the Lord. The man who is in such enlightenment, can see the truths of the church rationally while in the world, and spiritually after death. But from natural light (lumen) separated from spiritual light - which is the light of heaven from the Lord - to enter into the things of the church, which interiorly are spiritual and celestial, is to proceed according to an inverted order. For what is natural cannot enter into what is spiritual, but what is spiritual can enter into what is natural. For natural influx, which is also called physical influx, into the thoughts and intentions of a man's spirit is not possible. Spiritual influx, however, is possible, that is, of the thoughts and intentions of the spirit into the body, and also into its actions and sensations.