329. We can tell what a useful function is from the goal of the creation of the universe. The goal of the creation of the universe is to bring about an angelic heaven; and since an angelic heaven is the goal, so is humanity or the human race, since that is where heaven comes from. It follows, then, that everything that has been created is an intermediate goal, and that the functions are useful in the sequence, on the level, and in the specific way that they relate to humanity, and through humanity to the Lord.

302. There are in each world, in the spiritual world and in the natural world, three atmospheres, and these terminate in their final forms in such substances and materials as occur in the earth. We showed in Part Three, nos. 173-176, that there are in each world, in the spiritual world and in the natural world, three atmospheres, which are distinguished from each other in accordance with degrees of height, and which in their descent to lower levels decrease in accordance with degrees of breadth. Now because the atmospheres in their descent to lower levels decrease, it follows that they continually become more compressed and inert, until at last they become so compressed and inert that they are no longer atmospheres, but substances at rest, and in the natural world fixed, such as exist in the earth and are called material substances.

From this origin of substances and materials, it follows, first, that these substances and materials are also of three degrees. Secondly, that they are held in their connection with each other by the surrounding atmospheres. And thirdly, that they have been suitably constituted to produce all useful ends in their forms.