Inward things, or those pertaining to the angels of the inward heaven, are ineffable and cannot reach the understanding of humans. In fact, if they were to be exhibited, nothing but a kind of extreme darkness would appear. There is nothing they can be better compared to than the nerve tissues in the animate body, which flow marvelously out of the brains and marrows, branch off, very often intertwining, and insert themselves into the ganglia and lead to the internal organs, so that one can scarcely know the nature of the nervous system. Then they can be compared to the nervous tissues elsewhere that produce wonderful forms, as we can clearly see from a simple look at the pictures of nerve tissues. From these thus branching, bundling, flowing into each other, flowing out again and again, specific actions nevertheless come forth.