17. It is known, that, in order that anything may be perfect, there must be a trine in just order, one under another, and a communication between, and that this trine must constitute a one; no otherwise than as a pillar is a one, at the top of which is the capital, under this the smooth shaft, and under this again the pedestal. Such a trine is man: his highest part is the head, his middle part is the body, and his lowest the feet and soles. In this, every kingdom is like a man; there must be a king in it as the head, also administrators and officers as the body, and yeomanry with servants as feet and soles: in like manner in the church, there must be a filleted primate, parish priests, and curates under them. Nor does the world itself subsist without three things following in order, namely, morning, noon, and evening; as also the yearly spring, summer, and autumn; spring for the sowing of seeds, summer for their germination, and autumn for bringing forth fruit: but night and winter do not contribute to the stability of the world. [2] Now since every perfect thing must be a trine and cohere well together, in order to be a one, therefore each world, both spiritual and natural, consists and subsists from three atmospheres or elements; the first of which immediately encompasses the sun and is called aura; the second is under this and is called ether; and the third is under them both and is called air. In the natural world these three atmospheres are natural, and in themselves passive, because they proceed from a sun which is pure fire; but the three corresponding to them in the spiritual world are spiritual, and in themselves active, because they proceed from a sun which is pure love. [3] The angels of the heavens dwell in the regions of these three atmospheres; the angels of the highest heaven in the celestial aura, which immediately encompasses the sun where the Lord is; the angels of the middle heaven in the spiritual ether under the former; and the angels of the lowest heaven in the spiritual-natural air under those two. Thus are all the heavens co-established, from the first to this last which is being organized by the Lord at the present day. From these things it may be apprehended whence it is that by "three" in the Word is signified what is complete (see Apocalypse Revealed, n. 505, 875).