Human beings are born with a drive to experience modes of awareness other than the normal waking one; from very young ages, children experiment with techniques to change consciousness.
Such experiences are normal. Every person spends large amounts of time in other states, whether he or she retains awareness of them or not.
Altered states of consciousness form a continuous spectrum from ordinary waking consciousness. For example, there is no qualitative difference between watching a movie (light concentration) and being in a trance (deep concentration).
Although specific external triggers, such as drugs, may elicit these states, they do not cause them. Alternate states of consciousness arise from interactions among purely intrapsychic forces. External triggers provide opportunities for people to allow themselves certain experiences that may also be had without the triggers. Thus, a drug-induced state may be essentially the same as one induced by chanting or meditating.
It is valuable to learn to enter other states deliberately and consciously because such experiences are doorways to fuller use of the nervous system, to the realization of untapped human potential, and to better functioning in the ordinary mode of consciousness.
Nearly all commentators have recognized a fundamental dualism in the mind and have relegated different types of mental events to one of two opposite and complementary psychic spaces. There are many names for these two compartments, but there is also high consistency from system to system about their characteristics. That aspect of mind most active in ordinary waking consciousness, which uses intellect as the chief means of making sense of reality and manipulates verbal symbols, is often seen as masculine, right-handed (in the symbolic sense), and day-oriented. Complementing it and contrasting with it is the feminine, left-handed, night-time consciousness: the realm of dreams, intuitions, and nonverbal communication. I propose to use the terms solar and lunar to denote the two compartments of human mental activity.
If the psychological basis of altered states is some sort of interchange of energies between the solar mind and the lunar mind, what, then, is the situation in ordinary waking awareness? It seems reasonable to compare ordinary consciousness to ordinary daytime. The sun shines in the sky, and the moon is invisible. Many people in our society never see much of the moon. They live in cities, where buildings and artificial light hinder observation of the night sky, and they are indoors or asleep while the moon passes through its cycle. Reasoning by analogy, we may conclude that many people in our society are also relatively unconscious of the lunar forces within themselves. Possibly, the tendency to describe the lunar mind as unconscious indicates how commonly we deny it access to the ordinarily conscious solar mind.
Presumably, two distinct kinds of changes would alter the ordinary condition of the mind. Anything that diminished or focused the intensity of the solar mind might enable it to notice, and interact more with, the lunar mind. Anything that stimulated the lunar mind might permit it to achieve balance and interact with the solar mind. Various methods of achieving high states of consciousness illustrate these complementary approaches.