9215. 'It is his clothing for his skin' means that they also clothe relatively external things. This is clear from the meaning of 'clothing' as the sensory level in general or things on that level, as above; and from the meaning of 'skin' as that which is relatively external, which also clothes more internal things but still exists within those on the sensory level. What 'the skin' means, and who exactly correspond to the skin in the next life, see 3540, 5552-5559, 8977, 8980. The natural degree of the human mind has a rather internal level, a relatively external or middle level, and an outermost level. The more internal level of the natural is in contact with heaven; the middle or relatively external level is in contact on one side with the more internal, and through this with heaven, and on the other side with the outermost, and through this with the world, see 4009, 4570, 5118, 5126, 5497, 5649, 5707. The outermost level of the natural is that of the senses, which is meant here by 'clothing'. This level receives impressions of objects in the world and thereby serves more internal things. It is called 'his only covering' because it is the last and lowest and so is general to all, the relatively external or middle level of the natural being the one meant by 'skin'. From this it is evident that 'his clothing for his skin' means that the sensory level also clothes relatively external things. The fact that the sensory level is the last and lowest of a person's life, and so is a general covering, see 4009, 5077, 5125, 5128, 5767, 5774, 6201, 6313, 7442, 7693.

634. It is extremely difficult however to state intelligibly what the understanding of truth and the will for good are, properly speaking. The reason is that everything man thinks he ascribes to the understanding because he calls it so, and everything he desires he ascribes to the will because he calls it so. And it is even more difficult to state what they are in an intelligible way because the majority nowadays are also unaware that what belongs to the understanding is distinct and separate from what belongs to the will; for when they think something they say that they will it, and when they will something they say that they think it. Their speaking in this way is thus one reason for the difficulty. And a further reason why it is difficult to grasp the matter is that such people are engrossed solely in bodily interests, that is, their life consists in things of a more external nature.

[2] For these same reasons people are also unaware of the fact that with everybody there exists something interior, something more interior still, and indeed something inmost, and that the bodily and sensory part of a person is the most external. Desires and things of the memory are interior, affections and rational concepts more interior still, while the will for good and the understanding of truth are the inmost. Nothing could possibly be more distinct and separate than these are from one another, yet a bodily-minded man sees no difference at all, and so confuses them all with one another. This is the reason why he believes that when his physical body dies, everything else will die as well, when in reality only at that point does he start to live, and to do so indeed through his own interior things which are arranged in consecutive order. Unless man's interior things were distinct and separate in this way and arranged consecutively, men could not possibly be spirits, angelic spirits, or angels in the next life, all of whom differ in this way from one another according to things that are interior. Consequently the three heavens are very distinct and separate from one another. From all these considerations it now becomes clear to some extent what the understanding of truth and the will for good are, properly speaking, and that they are attributable only to the celestial man, or angels of the third heaven.