One primary fact of human existence is consciousness because it is present to, or underlies, every experience of every possible kind. Its nature and various states or modes are central to the human 'psyche'. Paradoxically, however, one of the most fundamental assumptions of Western science, though not always clearly expressed and simply assumed, is the primacy of matter over consciousness. The assumption is that materialism sees consciousness as a product of the sense data and that consciousness, which apparently (though unproven) has a potentially infinite grasp, arises from finite matter and that its development is (exclusively) dependent on material causes.
This assumption arises partly from the apparent fact that matter is observed to exist and persist and change independently of the consciousness of each individual person, while consciousness is generally experienced as limited to each person and appears to be dependent on the functioning of the living, functioning brain. However, in practically all world cultures, individuals have asserted that consciousness can be and is experienced as transcending all material and bodily conditions. Many recorded 'para-psychological phenomena' throughout history, though not investigated satisfactorily by the sciences so far, would seem to bear out the validity of such accounts.
That the primacy of matter over consciousness is an assumption, meaning
that it is not a proven fact. The opposite assumption, that consciousness is the ultimate cause and basis of existence is widely held in religious philosophies or theologies in the
Eastern tradition (especially the variants of Vedanta) - also found and often classified as 'idealism' in European thought
in neo-Platonic thinkers (Plotinus) and some philosophers (Berkeley) as well as in imported theories
from East to West from Vedantic thought, from Madame Blavatsky to Paul Brunton. Mentalism
would dispute the materialist assumption that consciousness arises from or is limited
to the physical senses, yet it remains a mere assumption (n1). In mentalism, consciousness takes primacy over consciousness
and is (supposedly) infinite in its scope. plus many alleged 'spiritual masters') or in the 'solipsism' of ancient Greeks like Protagoras and also in numerous New Age 'spiritual' theories. Their common presumption is that - whatever
common sense may seem to suggest - consciousness does not depend for its existence
on matter. It is considered not to be not generated through physical sensations of
material events. Depending on the variant of such mentalism involved, this does not necessarily apply to the mind and its various 'contents',
such as all the specific perceptions, sensations, thoughts, emotions, ideas,
desires, mental pictures etc. of which we can be aware.
All experiential phenomena, whether physical, mental or spiritual, are here regarded as being 'objects' of a person's consciousness, which is experiences itself as a purely subjective and private (outwardly not directly penetrable and as being 'inner'). 'Phenomena' here means that the objects of consciousness are 'what appear or are shown as being given to my awareness'. The following diagram helps explain this:-
The attempts of the experimental sciences to investigate consciousness in
search of a physical basis has become empirically stronger as technologies (like magnetic resonance imaging with vast computational powers of analysis) and neurological observation and experimentation have been developed.
Consciousness has therefore no longer proven to be entirely impenetrable to scientific
analysis and experiment. Moreover, many psycho-active agents, from old time cannabis, opium, morphine, mescaline to a host of newly discovered 'psychedelic' chemicals frequently cause experiences that are indistinguishable from those described by all manner of mystics East and West. In 'The Blissful Brian' by London's University College researcher in neurology and meditation, Dr. Shanida Nataraja, an expert practitioner in many traditional forms of meditation, has studied a range of mind-changing substances (LSD, DMT, mescaline, cannabis, and ketamine) and is convinced that the effects that can be achieved through these are no different from what mystics describe as their highest experiences, all of which are also only temporary. One famed mystic who fell into blissful trances utterly detached form 'the world', Ramakrishna Paramahamsa, made it very clear that the body organism cannot sustain itself indefinitely while being 'lost to the real world'. However, some still claim for their own purposes that they have it constantly, which is unproved and most likely a sustained deception for many personal reasons including control of followers and accumulation of worldly goods.
In the C20, some scientists explained consciousness as a kind of side-effect of existence - an 'epi-phenomenon' - or the perceived reflection of brain activity and not a direct phenomenon (or epistemological object) in itself. The former failures of most of the scientific community to admit the likelihood of differing kinds of experience and phenomena of an apparently 'extra-sensory' kind increasingly provided dissidents with religious/mystical leanings with some reasons for rejecting the materialistic thesis in favour of its contrary, mentalism or spiritualism and so forth. This leads into rational conjecture and hopeful speculation about the likelihood of an 'individual soul' and even a unifying 'spirit' (usually a God). These ancient beliefs have so far never produced anything remotely like scientifically-controllable evidence, mot least also because until the computer revolution, scientific instrumentation was virtually primitive in comparison to its vast exponential expansion to the present time. Around the turn of the century to 2000, great ingenuity and enormous efforts on many fronts in modern psychology, physiology, neurology and a range of allied sciences, has begun to lay the empirical basis for a theory of the functions and eventually of the nature of consciousness. The mentalist or spiritual view is allied to all manner of age-old beliefs that spirits cause everything and develops into doctrines that spirit suffuses the cosmos, being itself wholly immaterial. Spirit, qua God in some form or other, even came to fill the ultimate role of creator and regulator of the cosmos (or universe). This very soon leads into a quagmire of paradoxes, contradictions and denials of experience. Without going into too much detail here, the peculiar thesis of the primacy of consciousness versus matter (as in mentalism (eg. Brunton) Indian dualism (dvaita), and non-dualism (advaita), Berkeley's idealism and various modern equivalents and variants by isolated 'theorists', leaves many central issues completely unsolved. Physical materialism of that thesis also implies that many widely-held beliefs of mankind are false, from belief in anything that is not either directly given to our sensory equipment or perceptible by the use of instruments, and the resulting scientific world endeavour and the practical knowledge flowing from it has totally altered for the common good practically every aspect of individual and social life today.
In any awareness of anything, consciousness cannot be an object.3 This is to say that consciousness 'intends its object', which is stated formally by Brentano as "Consciousness is always consciousness of an object' (where object mean 'object of perception' nor simply a material or sense object - hence this includes ideas, feelings, anything of which we become aware (as an 'intentional object').
The assumption of the primacy of matter over consciousness (i.e. ontological materialism) means that explanations of human behaviour must be traced back to natural-physical events or causes, such as instincts or drives like 'libido' and bodily needs that the organism needs for self-preservation, genetic predispositions and much more. The contrary assumption (i.e. the ontological primacy of 'consciousness') holds that such a procedure is incapable of understanding human behaviour in terms of meaning, purpose, goal, will and value. This purposive or goal-oriented view (i.e. 'teleological explanation') is in contradiction to the non-teleological view of natural science, which rejects the transcendental belief - that purpose or meaning is inherent in the universe independent of the human organism.
Since the fact of being conscious seems to be closely related to the normal
functioning of the human brain, science regards consciousness as originating
only from the brain and as being totally dependent on it. However, mentalism - as in Platonic idealism, Vedanta and similar 'spiritual-mentalist' standpoints - most often holds that we conceive values, conscience, unrealized ideals and so forth by receiving these conceptions from a source outside the human mind and brain. The source is assumed to be from an 'inner' realm of universal consciousness (often identified as divine awareness or God-consciousness. There is no decisive or plausible proof that the brain is merely an instrument and channel of (some aspects of) an ever-present consciousness
emanating from 'out of this world'. For them, consciousness exists independently of the brain, which they compare to a radio or TV receiver which consciousness is comparable to the 'external' waves with various frequencies
to which it can be tuned in. Such an argument from analogy is logically invalid and is not to be considered seriously unless one wishes to enter the endless realms of empty - but possibly pleasing - conjectural dreaming.
In the modern scientific view, individual human consciousness only develops through taking in sensory impressions, and this begins already in the womb as the organism receives impressions. These stimulate the developing brain into awareness, aided by genetically inherited instincts. Eventually human consciousness comes to combine countless impressions and make increasingly coherent sense out of them, identifying common forms in them and abstracting them as primitive 'ideas'. These multiply and go through countless mental transformations as the mind and memory develops and abstracts interconnections through language and develops its internal topographies. Without language, the mind would have only a low level of awareness, such as in those lower animals which have no means of mutual expression and mutual understanding upon which complex systems of knowledge can be raised. Through language alone can the specific human faculty which combines clarity of thought, idea consistency and communicable expression arise.
Since values cannot be observed per se (i.e. through the senses), intellect and moral judgement are supposed by mentalists to be somehow 'immaterial' and supra-physical phenomena, having objective and immutable being, independent of and beyond the physical organism. They somehow impinge their form on our awareness in advance of sense perception, and often it is further held that have a permanent and immutable form. A traditional idea of truth as an unchanging and unchangeable quality, which is argued shows that values are immutable forms (as in Platonic idealism). These mentalist contentions have been refuted by influential modern philosophers, notably since John Locke and subsequently by most modern thinkers in the scientific tradition. . whereby the independence of permanent unchanging values, ideas, pure essence and much else, is due to a bewitchment of the mind by language (whereby, for example, various abstract nouns create the illusion of their substantive existence). That conceptions of 'the' immutable truth is primitive, is shown not least by the fact that there is no consensus anywhere of what is the truth. Science aims at the truth about phenomena, but not a 'the truth' as such for it can only be the truth about something, just as 'time' is an idea which has no referent as a thing or existent, being but is a measure of intervals between events. Science today will not endorse any claim of complete and uninfluenced 'objectivity' of knowledge, an 'eternal theory' or 'immutable wisdom' somehow existing independently of all brains, which are organisms that grow, change, and disintegrate. The origins of moral sense, conscience, values and all such cultural phenomena are easily explained without the assumption of spiritual realms or cosmic consciousness.
Reason requires that everything ultimately must either be generated from consciousness (sometimes called 'spirit') or from physical existence, no 'in-between view' is possible. Which of these most fundamental of assumptions is correct
and most fruitful cannot be decided by pure reason, and not even as such by scientific method alone. Assumptions are to be judged by their fruitfulness in advancing our knowledge, understanding of what exists and how well these enable the human project to progress, materially, technologically, culturally and in eliminating the ills of the world. How one judges will depend on one's total experience and one's level of insight and intellectual grasp of the sphere human knowledge and culture.
It is held in science that the human mind and its faculties are of a very subtle electro-magnetic and micro-biological nature, which can be measured by advanced scanning methods. Consciousness has at long last been made scientifically more and more accessible through analyzing the neurons and their connections experimentally. This is still, of course, a project underway, yet the precision of these researches - using recently developed vast computational resources - are already far superior to the most involved argumentation of centuries of major thinkers who have tried to study the mind and/or consciousness without the benefits of science.
1) The infinite Self of Vedic doctrine is not experienced as such in normal waking awareness, nor is the equally infinite Universal Consciousness within the range of any normal person's experience. It is a hypothesis which cannot be tested empirically. One may believe in it and claim to have experienced it, but this is entirely subjective.
2. Apropos and interestingly, Marvin L. Minsky, the inventor of Artificial Intelligence has stated that the mystery of consciousness is "trivial. I've solved it, and I don't understand why people don't listen." He also predicts (see Scientific American Nov. '93) that computers will someday evolve far beyond humans, who are nothing but "dressed-up chimpanzees". He holds that humans may be able to 'download' their personalities into computers and thereby become smarter and more reliable. There is much that indicates that such a process has already taken its first fumbling steps.
3) The thesis of intentionality, established by Franz Brentano and taken up by Continental philosophers from Hussert, Heidegger, Sartre and various neo-existentialists and in hermeneutics.