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Meditation comes in many forms. It is an important part of Buddhism and Hinduism and is practiced in Christianity and Islam as prayer. Buddhism stands apart from other religious systems of meditation because it stresses individual enlightenment rather than merger with God or a god. Western philosophers, especially Descartes (1641), have also practiced meditation to obtain introspective knowledge of the mind. Historically meditation was thought to be a method of transcending the material state and becoming closer to some non-material truth. More recently various techniques of meditation have been developed by materialists to maintain their health in the face of a harmful or distressing social environment.

Meditation will be discussed here in the context of introspective knowledge.

Yoga means 'joining' and expresses the Hindu belief that ultimate enlightenment involves joining with the divine. The Hindu tradition of meditation is encapsulated in books called Vedas and Upanishads. These books are extremely ancient (1500-200 BC) and require some interpretation for the modern world. Other books such as the Brahmanas were written as commentaries on the Vedas. The Brahma Sutra is a harmonisation of the Upanishads written around 0 AD by Bandarayanas. Another text, The Mahabharata (300BC-400AD), that is an epic about the war between the Pandavas and the Kauravas, contains the Bhagavad-gita that is also a source of meditational inspriration.

There are many forms of yoga, all of which involve an element of meditation. Jnana yoga involves the recognition of all things that are not eternal. It is documented in the Brahma Sutra. Karma yoga involves selfless service and underpins much of the Hindu religion. Bhakti Yoga involves worship and love of god and others. Both Karma and Bhakti yoga are documented in the Bhagavad-gita. Raja yoga is based on the Yoga Sutras that were written by Patanjali around 200 AD. It involves a demanding way of meditative living. Hatha yoga is documented in the medieval texts: Hatha Yoga Pradipika and the Gerhanda Samhita. It involves a rigorous set of exercises as well as meditation. Hatha yoga is particularly popular amongst those westerners that enjoy exercise.

The core of meditational technique for yoga was available in the Maitrayaniya Upanishad (300-200 BC) where the 'six fold path' is described. The six-fold path includes controlling the breath (pranayama), withdrawing the senses (pratyahara), meditation (dhyana), concentration (dharana), contemplation (tarka), and absorption or joining (samadhi).

The control of the breath (pranayama) has many forms. The important feature of breath control is that it focuses the attention on a single function and improves the practitioner's skill at breathing. This also allows breathing to be skilled and automatic during forms of meditation that do not focus on breathing.

The withdrawal of the senses (pratyahara) involves being able to ignore sensory input and also input from thoughts, day dreams, imaginings etc. It is sometimes accomplished by observing these things in a detached fashion. For instance, just listening and attending to verbal thoughts tends to make them go away. It is interesting that thought and sensations were regarded as equivalent events that are external to consciousness.

Concentration (dharana) is accomplished by attending to objects; sometimes these are physical objects and sometimes visualisations. This is done carefully and there should be no effort. The objective is to steady the mind, to stop it racing.

Dhyana can consist of focussing on the concept of objects as part of a totality, the totality being empty in its ultimate form (ie: that the qualia occupy an underlying space). Still other practictioners merge dhyana with pratyahara and suggest that meditation is careful attention to the shifting forms of thought and sensation. Yet others suggest that dhyana is the stopping of all thought. Interpolating from the Buddhist texts, it is likely that dhyana is the realisation of the underlying space and time of the mind.

Contemplation (tarka) is variously described as discrimination, contemplation or reasoning. It is the consideration of the progress of the other parts of the six-fold path.

Absorption or joining (samadhi) is a union in the mind with the object of contemplation. This union is at the level of an ecstatic oneness and, at the highest level of accomplishment, is a union with the divine or Krishna consciousness (see Nirvana and Religious Experience below).

This description of the use of meditation in yoga is based on the six-fold path. Some schools of meditation use slightly different techniques involving eight or more components.

Siddhartha Gautama was born about 563BC. He became known as 'Buddha' ('the awakened one') from the age of about thirty five. Buddha handed down a way of life that might lead, eventually, to an enlightened state called Nirvana.  In the three centuries after his death Buddhism split into two factions, the Mahayana (greater raft or vehicle) and the Theravada (the way of the elders). The Mahayana use the slightly derogatory term Hinayana (lesser raft or vehicle) for Theravada Buddhism. Mahayana Buddhism gave rise to other sects such as Zen Buddhism in Japan and Vajrayana Buddhism in Tibet. Mahayana Buddhism is more like a religion, complete with god like entities whereas Theravada Buddhism is more like a philosophy.

Theravada Buddhist meditation is described in books called the Pali Canon which contains the 'Vinayas' that describe monastic life, the 'Suttas' which are the central teachings of Theravada Buddhism and the 'Abhidhamma' which is an analysis of the other two parts or 'pitakas'. Two meditational systems are described: the development of serenity (samathabhavana) and the development of insight (vipassanabhavana). The two systems are complementary, serenity meditation providing a steady foundation for the development of insight. As meditation proceeds the practitioner passes through a series of stages called 'jhanas'. There are four of these stages of meditation and then a final stage known as the stage of the 'immaterial jhanas'.

The first jhana is a stage of preparation where the meditator rids themselves of the hindrances (sensual desire, ill will, sloth and torpor, restlessness and worry, and doubt). This is best achieved by seclusion. During the process of getting rid of the hindrances the meditator develops the five factors: applied thought, sustained thought, rapture, happiness and one-pointedness of mind. This is done by concentrating on a practice object until it can be easily visualised. Eventually the mediator experiences a luminous replica of the object called the counterpart sign (patibhaganimitta).

Applied thought involves examining, visualising and thinking about the object. Sustained thought involves always returning to the object, not drifting away from it. Rapture involves a oneness with the object and is an ecstacy that helps absorption with and in the object. Happiness is the feeling of happiness that everyone has when something good happens (unlike rapture, which is a oneness with the object of contemplation). One-pointedness of mind is the ability to focus on a single thing without being distracted.

The second jhana involves attaining the first without effort, there is no need for applied or sustained thought, only rapture, happiness and one-pointedness of mind remain. The second jhana is achieved by contemplating the first jhana. The second jhana is a stage of effortless concentration.

The third jhana involves mindfulness and discernment. The mindfulness allows an object of meditation to be held effortlessly in the mind. The discernment consists of discerning the nature of the object without delusion and hence avoiding rapture.

In the fourth jhana mindfulness is maintained but the delusion of happiness is contemplated. Eventually mindfulness remains without pleasure or pain. In the fourth jhana the meditator achieves "purity of mindfulness due to equanimity" (upekkhasatiparisuddhi).

Once the fourth jhana has been achieved the meditator can embark on the immaterial jhanas. There are four immaterial jhanas: the base of boundless space, the base of boundless consciousness, the base of nothingness, and the base of neither-perception-nor-non-perception.

The base of boundless space is achieved by meditating on the absence of the meditation object. It is realised that the space occupied by the object is boundless and that the mind too is boundless space. The base of boundless consciousness involves a realisation that the boundless space is boundless consciousness. The base of nothingness is a realisation that the present does not exist, the meditator should "give attention to the present non-existence, voidness, secluded aspect of that same past consciousness belonging to the base consisting of boundless space" (Gunaratana 1988). The base of neither-perception-nor-non-perception is a realisation that nothing is perceived in the void.

In Theravada Buddhism the attainment of the fourth jhana and its immaterial jhanas represents a mastery of serenity meditation. This is a foundation for insight meditation.

Buddhism is very practical and eschews delusions. It is realised that serenity meditation is a state of mind, a steady foundation that might, nowadays be called a physiological state. It is through insight meditation where the practitioner becomes a philosopher that enlightenment is obtained.

Prayer can take many forms but it is usually a 'communion' where the meditators talk to another entity that envelops them. The great psychologist William James (1902) in his "Varieties of Religious Experience" gives the following quotation describing Catholic prayer:

"It is the recollection of God, the thought of God, which in all places and circumstances makes us see him present, lets us commune respectfully and lovingly with him, and fills us with desire and affection for him.... Would you escape from every ill? Never lose this recollection of God, neither in prosperity nor in adversity, nor on any occasion whichsoever it be. Invoke not, to excuse yourself from this duty, either the difficulty or the importance of your business, for you can always remember that God sees you, that you are under his eye. If a thousand times an hour you forget him, reanimate a thousand times the recollection. If you cannot practice this exercise continuously, at least make yourself as familiar with it as possible; and, like unto those who in a rigorous winter draw near the fire as often as they can, go as often as you can to that ardent fire which will warm your soul.". Quoted by LEJEUNE: Introd. a la Vie Mystique, 1899, p. 66.

Prayer of this type is similar to the first jhana of Buddhist meditation, especially the Mahayana form of this, and to the joining with Krishna in yoga. James also gives an example of religious experience:

"I cannot express it in any other way than to say that I did 'lie down in the stream of life and let it flow over me.' I gave up all fear of any impending disease; I was perfectly willing and obedient. There was no intellectual effort, or train of thought. My dominant idea was: 'Behold the handmaid of the Lord: be it unto me even as thou wilt,' and a perfect confidence that all would be well, that all was well. The creative life was flowing into me every instant, and I felt myself allied with the Infinite, in harmony, and full of the peace that passeth understanding. There was no place in my mind for a jarring body. I had no consciousness of time or space or persons; but only of love and happiness and faith."

This is very similar to the sixth stage of the six fold path (samadhi) and the jhanas.

The similarity between samadhi, rapture in the first jhana and some forms of prayer and 'religious experience' is striking. The descriptions of the stages of meditation show that thoughts can be treated like sensations and also that conscious experience can exist without words. Conscious experience is described as a combination of qualia positioned in a mental space and time. The qualia include feelings of happiness and rapture. The Buddhists take this further and explore the mind without content, discovering a container with no boundaries, an empty form that underlies all experience. The contemplation of oneness with a universal God is a fast path to this level of realisation provided it is understood that the qualia themselves cannot be God.

A major problem in consciousness studies is that the western education system does not introduce students to meditative introspection. This results in a focus upon sensation in the Buddhist and yogic sense of the word. Students become very skilled at generating imaginary speech and attend to this sensation in preference to all other forms of mental activity. The Christian background of westerners has provided no restraint on this attention to verbal thought because verbal thought is a powerful tool of Christian meditation. This is why western authors have such difficulty defining consciousness, a difficulty that must puzzle Hindus and Buddhists. It is interesting that early western philosophers such as Descartes and Kant seemed to have far less difficulty defining and describing consciousness. Perhaps they were still living in an age of religious meditation (see Green (2002)).

Buddhists realise that 'serenity meditation' is just the first step, a platform from which to contemplate the universe. It is 'insight meditation' that leads to understanding. The advantage of using this sequence of attainments to contemplate the world is that consciousness is then part of common knowledge, not some embarrassing and mysterious inner secret. As Linde (2002) points out, it is becoming imperative to include consciousness in our physical description of the universe if the universe is to be understood.

The key features in 'serenity meditation' are relaxation, trust and, most important of all, observation. Serenity meditation is about the mind as it is, it is not some newly created state, so it can be achieved by patiently listening to thoughts and observing imaginary images and dreams. The exercises of yoga and the faith implicit in religious techniques provide the relaxation and trust in the body that are required for proper observation. Imaginary speech is the chief enemy of the modern meditator. Imaginary speech (especially discursiveness) obscures the mind to such an extent that we can become entirely unaware of our surroundings and of other modes of thought. Meditators might listen to their thoughts and occasionally ask 'who is saying this?' to remind themselves that the speech processor is only a small part of the self.

Dreams are sequences of images and feelings, often accompanied by sounds and other sensations, which occur during sleep. A few reports of dreams are given below.

"I saw two women singing on stage. They were dressed in long black dresses with black cowboy hats. Someone was talking in the audience. At the end of their song one of the women leapt off the stage, strode over to a man in the audience and slapped his face. The man started walking towards me, he had chubby pink cheeks, red on one side."

The subject reported that the night before he had been watching an award ceremony on television where two American women in red dresses were singing on stage. Someone had been talking in the room throughout the performance, which had mildly irritated him.

"I was lying in bed then woke up. A knight in armour was lying in the bed next to me where my wife should have been. He looked like the crusader in "Indiana Jones and the Holy Grail". I felt completely paralysed. I wanted to cry out. With a huge effort I managed to raise my arm and shout 'No!'. My wife shook me and woke me up. She said I had been waving my hands about shouting 'Nung, nung, nung'! I had been dreaming that I was awake with a knight in the bed, am I going crazy?"

In this report the subject dreams that he is awake. What is curious is the way the subject's body is paralysed, as it would have been if the subject were asleep. The subject is aware that he has no control over his body.

"I had had a car accident and was in hospital. I dreamt I was lying in my hospital bed, I looked up and someone in a stripy jacket was standing over the bed. I chuckled and said 'why is your mouth smiling and your eyes crying?'. The figure stopped smiling and raised a thick stick above its head. It swung the stick down striking my body with immense force. My whole body shook and it felt like I was emerging from the deep end of a swimming pool as I became awake. I wrote the dream down in a notebook because it really disturbed me. A couple of months later I was doing physiotherapy in the hospital. I had a walking stick. I staggered over to the mirror at the end of the room and saw, reflected in the glass the figure that had stood over the bed. It was wearing the stripy jacket my mother had bought me the week before."

In this dream the subject seems to be experiencing precognition. As can be seen from the examples, dreams can have a marked effect on the dreamer.

There are also several states of mind that are like dreams such as imagination, day dreaming, lucid dreaming and hallucinations. These seem to form a continuum from controllable small-scale imaginings to full-scale fantasies that totally immerse the subject.

The most common form of imagination is imaginary speech, most people call this 'thinking' but philosophers of mind often extend this term to include any activity that seems to come from the brain rather than the environment. Visual thinking by imagining objects is more difficult and is done in two ways. In the first type of visual imagination the eyes are closed and the subject tries to conjure up a visual form just in front of their eyes. In the second type the subject imagines things spread out in the places that they would occupy if they were real. The second type gives much more realistic imagery and seems to be preferred by artists who can sometimes imagine things on a canvass with their eyes open.

Vivid daydreams are popular with young people. They are often in the form of mini stories, perhaps enacting a mild fantasy or a part in a TV drama. When day dreaming with the eyes open there is little clear imagery but when day dreaming with the eyes shut the imagery can be much clearer. Daydreams are often guided by a narrative in imaginary speech (thinking) and in adults are often reduced to little more than free flowing, anxious, imaginary narrative. This inner narrative is used, especially in adults, to reinforce emotional states such as elation "yes, I can do it, when I do it it will be so good" or depression "nobody cares about me, I might as well not exist". The inner narrative often paints an emotional state rather than a visual picture and can modulate splanchnic activity.

Lucid dreaming is less common and allows the control of the dream experienced in day dreaming from within a sleeping state. It was described in detail by Frederik van Eeden in 1913:

"In these lucid dreams the reintegration of the psychic functions is so complete that the sleeper remembers day-life and his own condition, reaches a state of perfect awareness, and is able to direct his attention, and to attempt different acts of free volition. Yet the sleep, as I am able confidently to state, is undisturbed, deep and refreshing. I obtained my first glimpse of this lucidity during sleep in June, 1897, in the following way. I dreamt that I was floating through a landscape with bare trees, knowing that it was April, and I remarked that the perpective of the branches and twigs changed quite naturally. Then I made the reflection, during sleep, that my fancy would never be able to invent or to make an image as intricate as the perspective movement of little twigs seen in floating by."

These lucid dreams seem to be similar to the 'hypnagogic hallucinations' that were described by the French researcher Maury (1848). Notice how Frederik van Eeden is a naive realist, he simply dismisses the possibility that the brain could model a detailed world without realising that it does this all day long.

Hallucinations are rare in ordinary people but can be induced by the consumption of hallucinogens such as LSD, Mescaline etc. When the eyes are open these drugs tend to change the colours and forms of everyday objects. As an example a swathe of woodland leaves may appear to form the letters of the alphabet or clouds may adopt the form of ships or fists. If the eyes are closed the drugs allow daydreams with vivid imagery and emotional states that can run out of control.

These six states, perception, dreaming, imagination, daydreaming, lucid dreaming and hallucination seem to share many properties in common. The most important property is the way events in all of them occur in mental space and time. Freud (1911) in his excellent monograph "The Interpretation of Dreams" notes that dreams occur in a dreamworld that is like the real world in extent but contains fantasies:

" The characteristics of the dream-life thus far considered have been summed up by Burdach (p. 476) as follows: "As characteristic features of the dream we may state (a) that the subjective activity of our psyche appears as objective, inasmuch as our perceptive faculties apprehend the products of phantasy as though they were sensory activities... (b) that sleep abrogates our voluntary action; hence falling asleep involves a certain degree of passivity... The images of sleep are conditioned by the relaxation of our powers of will."

Imagination also occurs in mental space, even imaginary speech appearing to originate near the organs of real speech. Day dreams and lucid dreams occupy a dreamworld in mental space and hallucinations also overlay the sensory world of the mental space that contains perception. This coincidence of the location and 'feel' of the various states suggests that they may be sharing areas of the brain. MRI and PET studies have confirmed this, see Farah(1989), Bethoz (1996) and Jeannerod (1995). This overlay of brain activity in imaginary states with brain activity for normal states also applies to movements, imaginary speech and auditory hallucinations. Luft et al (1998) showed that imagining movements activated similar cerebellar areas similar to those used for actually performing the movements and Shergill et al (2000) have shown that auditory hallucinations in schizophrenic patients use similar areas of cortex to those used in normal speech. Tong (2003) points out that in dreaming and during schizophrenic visual hallucinations the primary visual cortex is not used although higher visual areas and association areas are implicated. The creation of dreams during sleep seems to be mediated by the frontal lobes as well as association areas because patients who have damage to the parieto-tempero-occipatal junction or the ventro-mesial quadrant can no longer dream (Solms 2000); without these areas the brain seems to be restricted to the modelling of sensation.

Manfred and Andermann (1998) have analysed a large range of hallucinatory states from visual hallucinations experienced by the blind (Charles Bonnet syndrome) to drug induced hallucinations. On the basis of the sites of damage they proposed that the hallucinations were due to abnormal functioning of a complex system involving modulation of cortical activity by the Raphe nucleus, the Lateral Geniculate nuclei, the Reticular Activating System and the Reticular Nucleus of the thalamus (modulated by intralaminar nuclei such as the parafascicular). The Raphe nuclei are part of an area of brain known as the 'periaqueductal grey matter' and contain neurones that use a range of serotonergic receptors. The Raphe nuclei are particularly sensitive to serotonin agonists such as LSD, mescaline and MDMA (ecstacy). Goaillard & Vincent (2002) have also shown that hallucinogens can modulate the activity of serotonin receptors in the intralaminar nuclei of the thalamus. These pathological findings support the established hypotheses that there is an 'activating' or 'arousal' system in the non-cortical brain that controls the passage of sensory data to the cerebral cortex and hence the activity of the cerebral cortex. (The reader who is interested in more information on these hypotheses and the nature of sleep is referred to the Behavioral and Brain Sciences Special Issue on Sleep and Dreaming (2000, 23:6) http://www.bbsonline.org/Preprints/OldArchive/sleep.html ).

If the various forms of imagining things activate similar areas of brain and create similar experiences then how do they differ from each other?  The principle differences involve how well the experiences are remembered, the amount of control that can be exercised, the vividness of the experiences and the ease with which they are disrupted. Dreams are the least well remembered form of imagining. In fact they are so poorly remembered that we can doubt whether we are actually conscious during dreams. Freud (1911) deals with the way that dreams are forgotten in some depth. He noted that anyone who has taken a special interest in dreams would have noticed how rapidly they could disappear from memory. It is usual in the short period between waking and walking out of the bedroom to forget a dream or even to forget that you are hoping to remember it. Lucid dreams and daydreams can be easily remembered as can general imaginings and most hallucinations. Ordinary dreams and hallucinations are least susceptible to control and although dreams cease on waking, hallucinations can persist in all states of consciousness. Dreams, lucid dreams and hallucinations are most vivid. Strong sensations can abolish dreams and lucid dreams but do not necessarily abolish hallucinations, daydreams and imaginary speech. Sudden, unusual sensations will usually disrupt daydreams and imaginary speech.

It seems that the brain has at its disposal a variety of ways of running its modelling activity. These range from the detailed modelling of sensation we call perception to the almost random associations of dreams. These all share the same mental space and there seems to be a series of gates or switches in the non-cortical brain that minimises the overlay of one sort of imagining on another. The two types of modelling that are most prevalent are perception (about 16 hours a day, disregarding daydreaming - see 'Reality' below) and dreaming. Dreaming is like perception without any sensory input, what we are experiencing is cortical activity without the constraint of any sensory template. The way that the vast majority of dreams are forgotten suggests that entire dreams are of little use to us. Unlike the overall content of dreams, the individual images and short sequences of events within them are definitely useful, being classifications of things and computations of the spatial and physical relations between things. When we experience a dream we are experiencing the inner workings of a supercomputer that can, in waking life, model the world of the senses at a glance. The classifications and spatial and physical relations calculated during sleep should allow the cortex to model the world more rapidly and accurately when we are awake.

This idea of dreams as a maintenance activity, preparing the brain for waking life, is probably the accepted wisdom in neuroscience. Theorists have tended however to concentrate on particular aspects of this activity, for instance many authors have stressed the possibility that dreams help memory consolidation (Jenkins and Dallenbach, Pearlman, Fishbein) whilst others have proposed that dreaming removes undesirable interactions in the cortex (Crick and Mitchison 1983) and Revonsuo (2000) considers that dreams help us to deal with threatening environments.

Precognition, seeing the future, is an aspect of dreams that is often left out of modern texts. Most dreams are not precognitive but many people have experienced at least one precognitive dream and many older accounts of dreaming included descriptions of precognitive dreaming. Modern authors usually avoid the discussion of precognitive dreaming altogether because it is very hard to calculate the probability of a random dream event subsequently occurring by chance in the succeeding years of waking life. However, although the possibility of precognitive dreaming is not accessible to scientific investigation it would be unwise to dismiss this (possible) phenomenon.

Other dream like states exist such as hypnosis, trance and intense play. According to subject's reports, hypnosis feels similar to daydreaming but unlike daydreaming, the subject integrates the hypnotist's suggestions as if they are the subject's own ideas (see bibliography 8). Trance states are also like daydreaming and the two terms are sometimes used interchangeably. Trance is a more intense experience than normal daydreaming, especially when it is coupled with self-hypnosis such as when a subject believes that a state of painlessness or lack of consciousness is occurring during the trance. The relationship between these states may become clearer with some examples:

Suppose you were a daydreamer relaxing at your office desk. You might imagine promotion. To have 'made it' will be so relaxing, no need to strive any more, people will just look up to you. You might visualise your new, smooth, silver, Mercedes car and large house, the acres of land and the swimming pool. How proud and relaxed your partner will be when there is such a large salary and the weekend barbecues on the patio will impress your family.

Suppose you were being hypnotised. You go along with it. You like the gentle, reassuring, warm tone. Yes, you are strong and fit. You smile gently to yourself and lightly rock your head, its true, you're relaxed. You take a deep breath and yawn slightly. It's good to sit and breathe sometimes. You look up and yawn and enjoy the air.... You breathe deeply and notice that this feels good and relaxing and read it again.

The two states are surprisingly alike. The daydream state differs slightly from a hypnotic induction script such as the above because it does not usually involve instructions for relaxing, breathing, moving etc. Hypnosis seems astonishing because we all believe that we have a conscious free will that derives from thinking verbally about things. As was shown in earlier chapters our verbal abilities are largely non-conscious and verbal decisions are always known after the non-conscious brain has made them. The non-conscious brain is capable of combining suggestions from a hypnotist with internal thoughts and presenting these as our own ideas.

The last state of mind that will be discussed here is 'play'. Consider two children in a cupboard or under a bed, they have an old radio set and both are lying down looking at it. The first turns to the other and says "fire phasers captain" and the other twiddles a knob on the radio and makes a sound of weapons fire. "We're going to get those Klingons!" he shouts. This sort of play is like a shared daydream. The conventional wisdom is that it provides a rehearsal of social and physical interactions that help to prepare children for adult life (see for instance Piaget 1962, Vygotsky 1978). At puberty children begin to play a single game and are discouraged from acting out their fantasies. 

A classification or model is 'true' if it exists in a particular 'universe of discourse'. The universe of discourse must always be defined before we attempt to evaluate whether or not particular relationships exist within it. A universe of discourse might be the words in this chapter so the statement "the chapter contains the text 'pigs might fly'" can then be verified by checking the entire chapter. (It is true - see the previous sentence). If the universe of discourse is 'fairy tales' then the statement 'unicorns have white teeth' may be true. On the other hand, if the universe of discourse is 'the inferred physical world excluding the brain, books of fairy tales etc.' then unicorns may not be found and their teeth may not be classified.

Post-structuralism is not true in almost any universe of discourse because it holds that properties are defined by difference from certain other properties. This is not true because each identifiable property is actually different from all other properties. Statements such as 'the meaning of white is the opposite of black' are not true whereas statements such as 'part of the meaning of white is not black', 'part of the meaning of white is not smoothness', 'part of the meaning of white is not hotness' are true. This is why Post-modernist statements seem like a set of lies, they are actually a set of half-truths (although technically lies). Difference is precisely the wrong property to use for analysing truth, truth is about things being the same or matching. 'Not the same' is all non-matching things so things that are different from a particular property are the entire universe of other properties and things, not a particular property. As was demonstrated in Chapter 1, a thing is known by being the same as itself, it is continuous with itself in space and time, this makes it unique, different from all other things, not only different from one particular thing. Half-truths are extremely useful in literary criticism and creative writing but are misleading when used in politics and form temporary hypotheses when used in science.

The combination of all possible universes of discourse is 'the universe'. The scientific view of the universe considers that many 'universes of discourse' within the universe are patterns in information processing machines or in brains. This view is almost the same as the philosophical view outlined above except that it proposes that all things are arrangements of physical things in a physical universe with unknown degrees of freedom for arranging things. Science holds that dreams are as real as houses but they are arrangements of things in the brain whereas houses are arrangements of things in the street. However, this is not what most people mean when they use the word 'real'.

So what is real? Thoughts and dreams are as real as motor cars but they are brain activity rather than physical objects outside the brain. Most people would describe the brain activity that is the experience called motor cars as more 'real' than the brain activity that is the experience called dreams. At first inspection the difference between the reality of motor cars and the unreality of dreams seems obvious but on closer examination this sort of reality is curiously difficult to define. It might be defined as the physical world but, as was shown in earlier chapters our minds contain a perceptual field that is based on the physical world rather than the physical world itself. Perhaps our own 'reality' could be defined as our perceptual field. But why should the emotive term 'reality' be reserved for the physical world or the perceptual field that correlates with this? The simple answer to this is that people who attend to 'reality' usually thrive whereas those who attend exclusively to 'unreality' become patients in asylums or may even die. It seems that the colloquial use of the terms 'real' and 'reality' apply to those parts of experience that are involved with the physical world, especially breathing, eating, drinking, working and the various tasks that allow us to thrive materially.

Any attempt at defining those things in our experience that are involved with " breathing, eating, drinking etc.." is fraught with difficulties. Meat does not just appear on a plate. There are hunting and farming skills that produce it, ethical codes that allow it, transport and marketing infrastructures that distribute it, the acquisition of money to purchase it and much more. It is also evident that engagement with the inferred physical world does not guarantee involvement with reality; if we spent all day building sandcastles we would be engaged with the physical world but not with reality. Doing nothing with your life but building sandcastles is enacting a crazy daydream. 'Reality' seems to be the games in our experience that match the requirements for continued life and these games are based on reveries or dreams that match the requirements for survival.

The use of the term 'dream' may seem extravagant for the experience of ordinary life but the only difference between modelling sensory input and dreaming seems to be whether of not sensation is used as the basis for the models. In both cases almost exactly the same areas of the brain are used and in both cases images and sounds occupy the same mental space and time. In other words, the brain creates models, when sensation is prominent the models are called perception, when sensation is not prominent the models are called dreams. This is slightly simplistic however because when the brain is modelling sensation it must do more than simply represent sensory objects because 'reality' includes skills, interactions and predictions. This means that our everyday experience is like a dream being updated by sensation rather than sensation being updated by thoughts. This is borne out by experiments on 'change blindness', illusions and most of the neuroscience of perception (see Chapter 2). Most people in sedentary occupations are probably doing very little modelling of sensation and their experience is largely a set of imaginings related to their job and other, unrelated daydreams, largely in the form of imaginary speech with weak imagery.

Our brain is a 'dream machine', a virtual reality generator. Its dreams are in harmony with 'reality' when they match the physical and social processes that allow us to thrive. This description of 'reality' suggests that there may be other valid 'realities' because there are many ways to thrive. If this is true then there should be societies and people around the world who lead different lives from our own. This is indeed the case. Islamic and Buddhist societies appear to be substantially different from Western societies and within these societies the aspirations and dreams of a soldier may differ markedly from those of a salesman or a cleric.

The colloquial term 'reality' describes a set of processes and, in previous chapters, it was shown that it is the non-conscious part of our brains that deals with these processes. This means that the colloquial use of the term 'reality' denies the value of the conscious part of our brain. But the conscious part of the brain is the most important part of us. Perhaps the colloquial use of the term 'reality' is the result of the demanding nature of modern life where people are considered failures unless they are committed to the processes of life. Unlike colloquial 'reality', the form that is consciousness is a personal thing that cannot be traded with other people. This creates a conflict between process and form that is one of the causes of recurrent daydreams that are out of harmony with day to day life. People either dream of a better, or at least different, life from the one in which they are trapped or may simply become fearful, anxious or depressed.

This conflict between process and form in our lives is well known. The Buddhists declare that most of the activities in life are delusions and most of the world's religions have a similar message. Unfortunately, although religions deal with this problem the solutions they offer are often far from clear and frequently obviously wrong. But this should not prevent us from searching for our own solutions to this problem, at the very least we might discover a way of living that values our form as well as our behaviour.

1. The Yoga Journal: History of Yoga.

http://www.yogajournal.com/history/vedas1.html

2. The Jhanas In Theravada Buddhist Meditation by Henepola Gunaratana. The Wheel Publication No. 351/353 ISBN 955-24-0035-X. 1988 Buddhist Publication Society.

http://www.accesstoinsight.org/lib/bps/index.html

3. The Lucidity Institute Inc. A discussion of dreams and especially lucid dreaming.

http://www.lucidity.com/

4. The Interpretation of Dreams (3rd edition) by Sigmund Freud. Translated by A. A. Brill (1911).

http://www.psywww.com/books/interp/toc.htm

http://www.bbsonline.org/Preprints/OldArchive/sleep.html

6. John Sutton's Dream Links

http://www.phil.mq.edu.au/staff/jsutton/Dreams.html

7. The Washington University School of Medicine Neuroscience Tutorial

http://thalamus.wustl.edu/course/sleep.html

8. The Neurophysiology of Hypnosis: Hypnosis as a State of Selective Attention and Disattention. Marcelle Bartolo Abela

http://www.uclm.es/inabis2000/posters/files/037/resultad.htm

9. Capturing Daydreams - a users guide to thought sampling. J Smallwood.

http://www.sci-con.org/editorials/reprints/20030901.pdf

Berthoz A. (1996). The role of inhibition in the hierarchical gating of executed and imagined movements. Brain Res Cogn Brain Res 3:101-113.

Crick, F. & Mitchison, G. (1983). The function of dream sleep. Nature. 1983 Jul 14-20;304(5922):111-4.

Farah, M.J. (1989). The neural basis of mental imagery. Trends Neurosci 12:395-399.

Goaillard, J. & Vincent, P. (2002). Serotonin suppresses the slow afterhyperpolarization in rat intralaminar and midline thalamic neurones by activating 5-HT₇ receptors. Journal of Physiology (2002), 541.2, pp. 453-465
http://jp.physoc.org/cgi/content/full/541/2/453

Green, A. (2002). The Description and Definition of Consciousness. Science and Consciousness Review, September No 2.

http://www.sci-con.org/news/articles/20020901.html

James, W. (1902) The Varieties of Religious Experience.

http://www.psywww.com/psyrelig/james/james5.htm#115

Jeannerod M (1995): Mental imagery in the motor context. Neuropsy- chologia 33:1419-1432.

Linde, A. (2002) Inflation, Cosmology and the Anthropic Principle.

http://arxiv.org/abs/hep-th/0211048

Luft,A.R., Skalej, M., Stefanou, A., Klose, U., & Voigt, K. (1998). Comparing Motion- and Imagery-Related Activation in the Human Cerebellum: A Functional MRI Study. Human Brain Mapping 6:105-113(1998)

http://airto.loni.ucla.edu/BMCweb/CourseWork/M285/PDF/Luft98.pdf

Manford, M. & Andermann, F. (1998). Complex Visual Hallucinations: clinical and neurobiological insights. Brain (1998), 121, 1819-1814.

http://brain.oupjournals.org/cgi/reprint/121/10/1819.pdf

Newberg, A. Iversen, J.(2003) The neural basis of the complex mental task of meditation: neurotransmitter and neurochemical considerations. Medical Hypotheses, 61:2, pp 282-289.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WN2-48W2S2C-2&_coverDate=08%2F31%2F2003&_alid=133033477&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=6950&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=062cadaa9d0e4753c5f28e9fd76c4c7e#toc4

Newberg A, Alavi A, Baime M, Pourdehnad M, Santanna J, d'Aquili E. (2001) The measurement of regional cerebral blood flow during the complex cognitive task of meditation: a preliminary SPECT study. Psychiatry Res. 2001 Apr 10;106(2):113-22.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11306250&dopt=Abstract

Piaget, J. (1962). Play, Dreams and Imitation in Children, W. W. Norton & Co., New York.

Revonsuo, A. (2000). The Reinterpretation of Dreams: An evolutionary hypothesis of the function of dreaming. , Behavioral and Brain Sciences 23 (6):

http://www.bbsonline.org/Preprints/OldArchive/bbs.revonsuo.html

Shergill SS, Brammer MJ, Williams SC, Murray RM, McGuire PK. (2000). Mapping auditory hallucinations in schizophrenia using functional magnetic resonance imaging. Arch Gen Psychiatry. 2000 Nov;57(11):1033-8.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11074868

Solms, M. (2000) DREAMING AND REM SLEEP ARE CONTROLLED BY DIFFERENT BRAIN MECHANISMS, Behavioral and Brain Sciences 23 (6): 793

www.bbsonline.org/Preprints/OldArchive/bbs.solms.html

Tong, F. (2003). Primary Visual Cortex and Visual Awareness. Nature Reviews Neuroscience 4, 219 (2003)

http://www.princeton.edu/~ftong/Tong_NRN2003.pdf

van Eeden, F (1913). A Study of Dreams.From Proceedings of the Society for Psychical Research, Vol. 26, 1913 copied and proofread by Blake Wilfong. http://www.lucidity.com/vanEeden.html

Vygotsky, L. (1978). "The Role of Play in Development". Mind in Society: The Development
of Higher Mental Processes. Cambridge: Harvard University Press.

Copyright 2004 by Alex Green PhD.