65. The useful functions of everything created tend upward, step by step, from the lowest to us, and through us to God the Creator, their source. As already stated [52], these "lowest things" are all the elements of the mineral kingdom--various forms of matter, some stony substances, some saline, some oily, some mineral, some metallic, with the constant addition of a humus composed of plant and animal matter reduced to minute particles. Here lie hidden the goal and the beginning of all the functions that arise from life. The goal of all useful functions is the effort to produce [more] functions; the beginning of all functions is an active force that comes out of that effort. These are characteristics of the mineral kingdom.

The intermediate things are all the elements of the plant kingdom--grasses and herbs of all kinds, plants and shrubs of all kinds, and trees of all kinds. Their functions are in support of everything in the animal kingdom, whether flawed or flawless. They provide food, pleasure, and life. They nourish [animal] bodies with their substance, they delight them with their taste and fragrance and beauty, and they enliven their desires. This effort is inherent in them from their life.

The primary things are all the members of the animal kingdom. The lowest of these are called worms and insects, the intermediate ones birds and animals, and the highest humans; for there are lowest, intermediate, and highest things in each kingdom. The lowest are for the service of the intermediate and the intermediate for the service of the highest. So the useful functions of all created things tend upwards in a sequence from the lowest to the human, which is primary in the divine design.

90. Because angels are spiritual beings, they cannot live in any other warmth or in any other light than spiritual warmth and light. On the other hand, people cannot live in any other warmth or in any other light than natural warmth and light. For a spiritual environment suits a spiritual being, and a natural one a natural being. If an angel were to draw the least bit of his existence from natural heat and light, he would perish, because it is unsuited to his life.

[2] Every person in the interiors of his mind is a spirit. When a person dies, he departs altogether from the world of nature, leaving all of its properties behind, and enters into a world which has not a speck of nature in it. And in that world he lives so detached from nature that he has no communication with it by any continuous connection, that is, by the kind of continuum that exists between something purer and something cruder, but by the kind of connection that exists between something prior and something subsequent, whose only communication is by correspondent relationships.

[3] It can be seen from this that spiritual heat is not a purer natural heat, and spiritual light a purer natural light, but that they are of an entirely different character; for spiritual heat and light take their character from a sun that is pure love, which is life itself, while natural heat and light take their character from a sun that is nothing but fire, which has in it absolutely no life (as we said above).