However, it is also argued that people function in a multitude of states of consciousness, both as individuals and one with another, and that different cultures have very different views concerning the recognition, utilization and attitudes towards altered states. This provides notions of non-ordinary reality which can be explored.
Psychologically, an altered state of consciousness is associated with a perceived qualitative shift in his pattern of mental functioning. That is, not just a quantitative shift (more or less alert, more or less visual imagery, sharper or duller, etc), but also that some quality or qualities of his mental processes are different. In such a case mental functions operate that do not operate ordinarily and perceptual qualities appear that have no normal counterparts. Thus "reality" is transformed. Examples of altered states of consciousness include: hypnagogic state (borderline between waking and sleeping); dream consciousness; meditative state; hypnotic trance; psychedelic drug-induced state. Altered states of consciousness may be induced by various physiological, psychological, or pharmacological manoeuvres or agents.
The philosophy of separate reality, or "stopping the world" was developed by don Juan/Carlos Castaneda through the use of hallucinogenic drugs. By transcending ordinary reality one acquires wisdom of the right way to live. Ordinary reality, or the world view, is simply one interpretation of what really is. In order to stop the world "one has to learn the new description in a total sense, for the purpose of pitting against it the old one, and in that way break the dogmatic certainty, which we all share, that the validity of our perceptions, or our reality of the world, is not to be questioned".
"Raw reality" is a term from the philosophical/religious approach of the Institute for Cultural Affairs, in which one aspect of being in the presence of transcendence is having "inclusive collegiality with symbols of profound living", through which one develops the ability to see through symbols to their depth significance. This is when existence reveals itself in some wholly unprecedented way which one seeks to remember; when a situation or an individual is experienced as the wholly "other", beyond the universe of meaning in which one is accustomed to live, whose presence demands that that universe change. Pablo Picasso's painting "Guernica" may be said to represent this experience among villagers upon whom a saturation bombing experiment was conducted.
In Hinduism, apparent reality as viewed by the human being (maya) is the result of five outer sheaths masking or veiling the truth. These sheaths have to be progressively transcended in order to attain ultimate realization. It is not that what is perceived does not exist but that erroneous perception sees it for what it is not. Awareness of relative reality is conveyed, through the path of yoga, by understanding the conditional states of consciousness: three dominated by the objective influence of the ego, a fourth objective state of pure knowledge and a supra-conscious state of being in union with one's god.
In virtual reality -- a world of electronic realities created by interaction between human beings and computers -- the modern individual can experience being someone or something else, or combinations of other people and things. The experience of reality transference is as powerful as that induced by psychedelic drugs, so that previously immutable reality becomes fluid with multiple references of reality valid at any given moment. This experience permanently changes perception of the "real" world.
Ontology is the study of the principles of being or reality, as a branch of philosophy, metaphysics or theology.