Selection from Apocalypse Explained ~ Emanuel Swedenborg
And the Lord shall make thee the head, and not the tail; and thou shalt be above only, and thou shalt not be beneath; if that thou hearken unto the commandments of the Lord thy God, which I command thee this day, to observe and to do them (Deut. 28:13)."To make as the head" means to make spiritual and intelligent, and thus to elevate out of the light of the world into the light of heaven; and "to make as the tail" means to make sensual and foolish, so as not to look to heaven but only to the world; therefore it is said "and thou shalt be above only, and thou shalt not be beneath," "to be above" meaning to be elevated by the Lord so as to look to heaven, and "to be beneath" meaning not to be elevated by the Lord, but by self, and man by self looks only to the world. For man's interiors, which belong to his thought and affection, are elevated to heaven by the Lord when man is in the good of life and thence in the truths of doctrine; but when he is in the evil of life and thence in falsities, his lower things look downward, thus only to his body and to such things as are in the world, and thus to hell. Thus man puts off his truly human nature and puts on a beastly nature, for beasts look downward and to such things only as are met with in the world and upon the earth. Elevation into the light of heaven by the Lord is an actual elevation of man's interiors to the Lord; and a depression or casting down to such things as are below and outside the eyes is an actual depression and casting down of the interiors, and when this takes place, all the thought of the spirit is immersed in the ultimate sensual.
Sensual knowledges are such knowledges as enter from the world through the five bodily senses, and thence viewed in themselves are more material, corporeal, and worldly than those that are interior. All who are in the love of self and have confirmed themselves against Divine and spiritual things are sensual men, and when they are left to themselves and think in their spirit, they think about Divine and spiritual things from sensual knowledges, and consequently they reject Divine and spiritual things as not to be believed, because they do not see them with their eyes or touch them with their hands; and they apply their knowledges - which they have made sensual and material - to the destruction of these. For example, men who are learned in this kind of knowledge, who are skilled in physics, anatomy, botany, and other branches of human learning, when they see the wonderful things in the animal and vegetable kingdoms say in their hearts that all these things are from nature, and not from the Divine, and this because they believe in nothing that they do not see with their eyes and touch with their hands; for they are unable to elevate their minds upward so as to see these things from the light of heaven, for that light is thick darkness to them; but they detain their minds in earthly things, much the same as the animals of the earth do, with which indeed they compare themselves.
In a word, with such all knowledges [scientiae] are made sensual; for such as the man himself is, such are all things of his understanding and will; if the man is spiritual all things become spiritual; if he is merely natural all things become natural and not spiritual; if the man is sensual all things become sensual, and this however learned and erudite he may seem to the world to be.But as every man has the faculty to understand truths and perceive goods, such men are able from that faculty to talk about these things like those who are spiritual-rational, although in respect to their spirit they are sensual; for when such men speak before others, they do not speak from the spirit but from the bodily memory.
All this has been said to make known what sensual knowledges are. These are what especially persuade, or are especially persuasive, because they are the ultimates of the understanding; for into these, as into its ultimates, the understanding closes, and these captivate the common people because they are appearances drawn from such things as they see in the world with their eyes; and so long as the thought clings to these it is impossible to dispose the mind to think interiorly or above them until they are put away; for the interior things of the mind all close into ultimates and rest upon them, as a house upon its foundation; consequently these are especially persuasive, but only with those whose minds cannot be elevated above sensual things; and the mind is elevated above them with those who are in the light of heaven from the Lord, for the light of heaven dissipates them. For this reason spiritual men rarely think from things sensual, for they think from things rational and intellectual; but sensual men, who have confirmed themselves in falsities against Divine and spiritual things, when they are left to themselves think only from sensual things.
(from Apocalypse Explained 559:6,2-3)