By the ancients man was called a microcosm, from his representing the macrocosm, that is, the universe in its whole complex; but it is not known at the present day why man was so called by the ancients, for no more of the universe or macrocosm is manifest in him than that he derives nourishment and bodily life from its animal and vegetable kingdoms, and that he is kept in a living condition by its heat, sees by its light, and hears and breathes by its atmospheres. Yet these things do not make man a microcosm, as the universe with all things thereof is a macrocosm. The ancients called man a microcosm, or little universe, from truth which they derived from the knowledge of correspondences, in which the most ancient people were, and from their communication with angels of heaven; for angels of heaven know from the things which they see about them that all things of the universe, viewed as to uses, represent man as an image. 320. But the truth that man is a microcosm, or little universe, because the created universe, viewed as to uses is, in image, a man, cannot come into the thought and from that into the knowledge of any one on earth from the idea of the universe as it is viewed in the spiritual world; and therefore it can be corroborated only by an angel, who is in the spiritual world, or by some one to whom it has been granted to be in that world, and to see things which are there. As this has been granted to me, I am able, from what I have seen there, to disclose this arcanum. 321. It should be known that the spiritual world is in external appearance, wholly like the natural world. Lands, mountains, hills, valleys, plains, fields, lakes, rivers, springs of water are to be seen there, as in the natural world; thus all things belonging to the mineral kingdom. Paradises, gardens, groves, woods, and in them trees and shrubs of all kinds bearing fruit and seeds; also plants, flowers, herbs, and grasses are to be seen there; thus all things pertaining to the vegetable kingdom. There are also to be seen there, beasts, birds, and fishes of every kind; thus all things pertaining to the animal kingdom. Man there is an angel or spirit. This is premised that it may be known that the universe of the spiritual world is wholly like the universe of the natural world, with this difference only, that things in the spiritual world are not fixed and settled like those in the natural world, because in the spiritual world nothing is natural but every thing is spiritual.