Selection from Apocalypse Explained ~ Emanuel Swedenborg
... the natural of man is threefold - rational, natural, and sensual; the rational is the highest in it, the sensual is the lowest, and the natural is the middle. The genuine rational is from influx from the spiritual world, the sensual is from influx from the natural world, and the mediate natural is either of the rational or of the sensual.That the natural is threefold can be seen in men who while they are in the world are either rational or sensual or intermediate. Which of these they are is clear especially from their perception of civil, moral and spiritual laws.Those are rational who think, judge, and conclude well from reason, and the thoughts of such are raised above material things; but those who are sensual think from material things and in them, and what they speak from thought is only from the memory. As there are these two degrees, there is also an intermediate degree which is called the natural. What men are can be known also from their understanding of the Word. The rational draw from the sense of the letter such things as pertain to doctrine, while the sensual abide in the letter only and draw from it nothing more interior. The same distinctions exist in the spiritual world, since in the lowest heaven there are the same degrees of natural men; the lowest there are the sensual, and the highest the rational ...
(Apocalypse Explained 1147)