Four Element Theory

The universe, or totality of that which is, can be divided in two: (a) observer or inner world; (b) observed, or material world, or world of the senses, or outer world. Note that outer world includes the body. Inner world can in turn be divided in two: (a) changeable inner world, or mind, or spirit; (b) unchangeable inner world, or animal self, or soul.

Desire from soul interpreted by spirit. Spirit controls muscles, which cause change to sensory world, resulting in change to incoming sense impressions. These are interpreted by spirit (with possible update to memory stores), resulting in pleasure or pain, which in turn results in new desire, thus completing feedback loop.

Earth is the outer world of the senses. Fire, air and water compose the inner world. Air is the spirit, or mutable inner world. Fire and water are the dual (male and female) aspects of the soul, the immutable inner world. Fire is outgoing desire, water is incoming pleasure and pain.

Distinguishing spirit, or realm of illusion, from soul, or realm of reality, is not always easy. Desire can be either true desire, springing from the soul, or illusory desire, cooked up by the spirit. True desire, represented by fire, is the motive power of the universe. Similarly, pleasure can be either true pleasure or illusory pleasure. True pleasure, represented by water, is the purpose of the universe. That is, the goal of the universe is to quench the fire of desire in the waters of bliss.

It is possible for highly developed spirit to overwhelm soul. Because spirit is so malleable, it can, in theory, interpret incoming sense impressions however it chooses. Everything can be interpreted as giving rise to pleasure, or everything can be interpreted as giving rise to pain. In practice, few have such a highly developed and perfectly controlled spirit as to accomplish this feat. Few can smile like the martyrs as they are being tortured to death. Indeed, more common is for people who should be happy, because their soul is happy (physical pleasure without much physical pain) to be afflicted by some sort of spiritual illness which causes their overall mood to be one of unhappiness.

Though air intervenes both between fire and earth and between earth and water, the latter intervention is more important, which is why the astrological signs are arranged in the order fire, earth, air, water. Also, water signs in astrology refer to feedback which brings about future desires, rather than to pleasure and pain. Water signs are thus transitional signs in astrology.