# Consciousness Studies/Introduction#Intended audience and how to read this book

Everyone has their own view of the nature of consciousness based on
their education and background. The intention of this book is to expand
this view by providing an insight into the various ideas and beliefs on
the subject as well as a review of current work in neuroscience. The
neuroscientist should find the philosophical discussion interesting
because this provides first-person insights into the nature of
consciousness and also provides some subtle arguments about why
consciousness is not a simple problem. The student of philosophy will
find a useful introduction to the subject and information about
neuroscience and physics that is difficult to acquire elsewhere.

It is often said that consciousness cannot be defined. This is not true;
philosophers have indeed defined it in its own terms. It can be
described in terms of two principal components: firstly **phenomenal
consciousness** which consists of our experience with things laid out in
space and time, sensations, emotions, thoughts, etc., and secondly
**access consciousness** which is the processes that act on the things
in experience. Phenomenal consciousness is much like the "perceptual
space" of psychological and physiological research. It is the many
simultaneous events that become the space of experience in general and
it is now a legitimate target of scientific research.

As will be seen in the following pages, the issue for the scientist and
philosopher is to determine the location and form of the things in
phenomenal consciousness and even to consider whether such a thing could
exist. Is phenomenal consciousness directly things in the world beyond
the body, is it brain activity based on things in the world and internal
processes --- a sort of virtual reality --- or is it some spiritual or
other phenomenon?

## A note on Naive Realism

The study of consciousness may seem to be esoteric or outside of the
main stream but it includes some very real problems in science and
philosophy. The most obvious problem is how we can see anything at all.
Many people with a smattering of geometry tend to believe that they have
a \'point eye\' that sees the world, and this idea is known as
perceptual \"Naive Realism\". Physical considerations show that this
idea is highly contentious; we have two eyes with different images in
each, normally the only images in the world are created by optical
instruments such as the eye, and the photons that carry light to the
observer cannot and do not all converge at a single point. Some of the
discrepancies between the physical reality and our experience are shown
in the illustrations.

![](Constudnaive1.png "Constudnaive1.png")
![](constudnaive2.GIF "constudnaive2.GIF")

The naive realist idea of perception involves a point eye looking at a
geometrical form. But the physics is different; there are two eyes with
sometimes very different images in each. Light is refracted over the
entire area of the cornea and directed over the entire area of the
retina - there is no \'point eye\'.

The cloud of photons that compose light must get in the way of the view
but naive realism neglects this, regarding the photons as somehow
transparent yet gathering as an impossible group of millions of photons
in a viewing point.

Light rays go everywhere, it is only after light has passed through an
optical instrument such as the eye that an image is formed. Hold up a
sheet of paper - there are no images on it.

![](Constudnaive4.png "Constudnaive4.png")The illustrations show the
nature of one of the most difficult problems studied by neuroscience:
how can the images on the two retinas become experience? How can we
imagine things or experience dreams and hallucinations? Studies on the
neural basis of binocular rivalry and MRI studies of imagination are
leading the way in our comprehension of these problems but there is
still **no physical theory that is congruent with sensory experience**.
The problem of *binding* also takes us further from Naive Realism; we
experience speech at the mouth of the speaker even though we might be
listening through headphones, how is sound, touch etc. bound to vision?
The objective of the scientific study of consciousness is to discover
how we convert data from the world into our experience.

A degree of Naive Realism is a sensible idea for coping with the
everyday problems of working and living. Most physical scientists and
people in general are, to some extent, Naive Realists until they study
the biology of sensation and the problems of perception and
consciousness. There is often a suspicion, or even fear, amongst Naive
Realists that any analysis of conscious experience is a suggestion that
the world does not exist or everything is imaginary. These fears are
unfounded: Neuroscience is a study of the part of the physical world
represented by brain activity and is part of medicine.

## Intended audience and how to read this book

This book is intended as a complementary text for neuroscience and
philosophy degree courses. The book is divided into four parts. If you
are not interested in some part, skip to the next. The first part is a
detailed historical review of the philosophy of phenomenal
consciousness. The second part is a discussion of philosophical
theories, it is intended to be challenging and even irritating.
Philosophy undergraduates are encouraged to criticise and react to this
part. The third part is a review of the neuroscience of consciousness
and is suitable for undergraduate studies in the field. The end of the
book is a discussion of theories of consciousness.

Being freely available to all students the book can serve as a source
for seminars even if you disagree with the content i.e.: "Why is (a
given section) an oversimplification/biased/out of date etc.?"

The text covers a difficult area that straddles the humanities and
science faculties. It is probably more oriented towards the scientist
who needs a scientific insight into philosophical theory rather than
vice versa. It is suitable as a **supplementary text** for the following
**undergraduate** modules, units and courses:

-   Neurophysiology/Neurobiology modules (physiology of perception,
    physiology of consciousness, neuronal basis of consciousness)
-   Neuropsychology modules
-   Neuroanatomy modules
-   Cognitive psychology/Cognitive science
-   Psychology of consciousness
-   Psychology - behaviourism vs cognitivism debate
-   Philosophy of mind and metaphysics
-   Computing - Artificial intelligence and consciousness
-   Consciousness studies courses

This is a "Wikibook" and, in this edition, has more breadth than depth.
In some areas, particularly in the huge field of the philosophy of
consciousness, topics are introduced and the obvious flaws or successes
pointed out but a fully referenced, in-depth treatment is sometimes
absent at this stage. We need your help and contributions from scholars
in the field are invited. Please contribute but please, at the very
least, scan the book first to ensure that your prospective contribution
has not been included already! In particular contributors who wish to
write "all self respecting scientists think that the brain is a digital
computer" should read the section on information theory and add their
contribution to the section on the possibility of conscious digital
computers.


# Consciousness Studies/Early Ideas

*This section is an academic review of major contributions to
consciousness studies. Readers who are interested in the current
philosophy of consciousness will find this in Part II and readers
interested in the neuroscience of consciousness should refer to Part
III.*

Vedic Sciences are present the first known ideas related to
consciousness, dating back to at least 1500 years ago according to The
British Library. The ten books of Rig Veda, which are attributed to the
end of the Bronze period, which are on of the ten oldest living texts of
the world, illuminates us on ultimate or supreme consciousness. In the
Rig Veda (R.V. IV. XL. 5) Nrishad is the dweller amongst humans; Nrishad
is explained as Chaitanya or \'Consciousness\' or Prana or \'vitality\'
because both dwell in humans.

In his commentary on the Isha Upanishad,\[5\] Sri Aurobindo explains
that the Atman, the Self manifests through a seven-fold movement of
Prakrti. These seven folds of consciousness, along with their dominant
principles are:\[6\]

annamaya puruṣa - physical prāṇamaya puruṣa - nervous / vital manomaya
puruṣa - mental / mind vijñānamaya puruṣa - knowledge and truth
ānandamaya puruṣa - Aurobindo\'s concept of Delight, otherwise known as
Bliss caitanya puruṣa - infinite divine self-awareness\[7\] sat puruṣa -
state of pure divine existence

The first five of these are arranged according to the specification of
the panchakosha from the second chapter of the Taittiriya Upanishad. The
final three elements make up satcitananda, with cit being referred to as
chaitanya.

The essential nature of Brahman as revealed in deep sleep and Yoga is
Chaitanya (pure consciousness).\[8\]

The earliest use of the word soul or Ātman in Indian texts is also found
in the Rig Veda (c. 1500 BC)(RV X.97.11).\[20\] Yāska, the ancient
Indian grammarian, commenting on this Rigvedic verse, accepts the
following meanings of Ātman: the pervading principle, the organism in
which other elements are united and the ultimate sentient
principle.\[21\]

Other hymns of Rig Veda where the word Ātman appears include I.115.1,
VII.87.2, VII.101.6, VIII.3.24, IX.2.10, IX.6.8, and X.168.4.\[22\]

The Rig Veda takes one from before creation, through creation of the
world, to creation of self, and ends with the creation of creation
itself, after which creation of the universe came. Upon close reading,
one can trace the various stages of consciousness to the material world,
from absolute truth or Sat to absolute material or Asat, two recurring
concepts that run through the entire Rig Veda.

The Greeks had no exact equivalent for the term \'consciousness\', which
has a wide range of meanings in modern usage, but in the thinkers below
we find an analysis of phenomenal consciousness and the source of many
ideas developed by later Socratics, especially the Stoics, and by
Christian thinkers like Augustine.

## Aristotle (c. 350 BC) *On the Soul*

(De Anima) <http://psychclassics.yorku.ca/Aristotle/De-anima/>

!AristotleAristotle, perhaps more
than any other ancient Greek philosopher, set the terms of reference for
the future discussion of the problem of consciousness. His idea of the
mind is summarised in the illustration
below.![](Constudaristotle.png "Constudaristotle.png")

Aristotle was a physicalist, believing that things are embodied in the
material universe:

`<font face="times new roman">`{=html}\"\... That is precisely why the
study of the soul \[psyche\] must fall within the science of Nature, at
least so far as in its affections it manifests this double character.
Hence a physicist would define an affection of soul differently from a
dialectician; the latter would define e.g. anger as the appetite for
returning pain for pain, or something like that, while the former would
define it as a boiling of the blood or warm substance surround the
heart. The latter assigns the material conditions, the former the form
or formulable essence; for what he states is the formulable essence of
the fact, though for its actual existence there must be embodiment of it
in a material such as is described by the other.\"(Book I,
403a)`</font>`{=html}

The works of Aristotle provide our first clear account of the concept of
signals and information. He was aware that an event can change the state
of matter and this change of state can be transmitted to other locations
where it can further change a state of matter:

`<font face="times new roman">`{=html}\"If what has colour is placed in
immediate contact with the eye, it cannot be seen. Colour sets in
movement not the sense organ but what is transparent, e.g. the air, and
that, extending continuously from the object to the organ, sets the
latter in movement. Democritus misrepresents the facts when he expresses
the opinion that if the interspace were empty one could distinctly see
an ant on the vault of the sky; that is an impossibility. Seeing is due
to an affection or change of what has the perceptive faculty, and it
cannot be affected by the seen colour itself; it remains that it must be
affected by what comes between. Hence it is indispensable that there be
something in between-if there were nothing, so far from seeing with
greater distinctness, we should see nothing at all.\" (Book II,
419a\])`</font>`{=html}

He was also clear about the relationship of information to \'state\':

`<font face="times new roman">`{=html}\"By a \'sense\' is meant what has
the power of receiving into itself the sensible forms of things without
the matter. This must be conceived of as taking place in the way in
which a piece of wax takes on the impress of a signet-ring without the
iron or gold; we say that what produces the impression is a signet of
bronze or gold, but its particular metallic constitution makes no
difference: in a similar way the sense is affected by what is coloured
or flavoured or sounding, but it is indifferent what in each case the
substance is; what alone matters is what quality it has, i.e. in what
ratio its constituents are combined\"(Book II, 424a)`</font>`{=html}

Aristotle also mentioned the problem of the simultaneity of experience.
The explanation predates Galilean and modern physics so lacks our modern
language to explain how many things could be at a point and an instant:

`<font face="times new roman">`{=html}\"\... just as what is called a
\'point\' is, as being at once one and two, properly said to be
divisible, so here, that which discriminates is qua undivided one, and
active in a single moment of time, while so far forth as it is divisible
it twice over uses the same dot at one and the same time. So far forth
then as it takes the limit as two\' it discriminates two separate
objects with what in a sense is divided: while so far as it takes it as
one, it does so with what is one and occupies in its activity a single
moment of time. (Book III, 427a)`</font>`{=html}

He described the problem of recursion that would occur if the mind were
due to the flow of material things in space:

`<font face="times new roman">`{=html}\"\...mind is either without parts
or is continuous in some other way than that which characterizes a
spatial magnitude. How, indeed, if it were a spatial magnitude, could
mind possibly think? Will it think with any one indifferently of its
parts? In this case, the \'part\' must be understood either in the sense
of a spatial magnitude or in the sense of a point (if a point can be
called a part of a spatial magnitude). If we accept the latter
alternative, the points being infinite in number, obviously the mind can
never exhaustively traverse them; if the former, the mind must think the
same thing over and over again, indeed an infinite number of times
(whereas it is manifestly possible to think a thing once only).\"(Book
I, 407a)`</font>`{=html}

Aristotle explicitly mentions the regress:

`<font face="times new roman">`{=html}\"..we must fall into an infinite
regress or we must assume a sense which is aware of itself.\" (Book
III,425b)`</font>`{=html}

However, this regress was not as problematic for Aristotle as it is for
philosophers who are steeped in nineteenth century ideas. Aristotle was
a physicalist who was not burdened with materialism and so was able to
escape from the idea that the only possibility for the mind is a flow of
material from place to place over a succession of disconnected instants.
He was able to propose that subjects and objects are part of the same
thing, he notes that thought is both temporally and spatially extended:

`<font face="times new roman">`{=html}\"But that which mind thinks and
the time in which it thinks are in this case divisible only incidentally
and not as such. For in them too there is something indivisible (though,
it may be, not isolable) which gives unity to the time and the whole of
length; and this is found equally in every continuum whether temporal or
spatial.\" (Book III,430b)`</font>`{=html}

This idea of time allowed him to identify thinking with the object of
thought, there being no need to cycle thoughts from instant to instant
because mental time is extended:

`<font face="times new roman">`{=html}\"In every case the mind which is
actively thinking is the objects which it thinks.\"`</font>`{=html}

He considered imagination to be a disturbance of the sense organs:

`<font face="times new roman">`{=html}\"And because imaginations remain
in the organs of sense and resemble sensations, animals in their actions
are largely guided by them, some (i.e. the brutes) because of the
non-existence in them of mind, others (i.e. men) because of the
temporary eclipse in them of mind by feeling or disease or sleep.(Book
III, 429a)\"`</font>`{=html}

And considered that all thought occurs as images:

`<font face="times new roman">`{=html}\"To the thinking soul images
serve as if they were contents of perception (and when it asserts or
denies them to be good or bad it avoids or pursues them). That is why
the soul never thinks without an image.\"(Book III, ).`</font>`{=html}

Aristotle also described the debate between the cognitive and
behaviourist approaches with their overtones of the conflict between
modern physicalism and pre twentieth century materialism:

`<font face="times new roman">`{=html}\"Some thinkers, accepting both
premisses, viz. that the soul is both originative of movement and
cognitive, have compounded it of both and declared the soul to be a
self-moving number.\"(Book I, 404b)`</font>`{=html}

The idea of a \'self-moving number\' is not as absurd as it seems, like
much of Ancient Greek philosophy.

Aristotle was also clear about there being two forms involved in
perception. He proposed that the form and properties of the things that
are directly in the mind are incontrovertible but that our inferences
about the form and properties of the things in the world that give rise
to the things in the mind can be false:

`<font face="times new roman">`{=html}\"Perception (1) of the special
objects of sense is never in error or admits the least possible amount
of falsehood. (2) That of the concomitance of the objects concomitant
with the sensible qualities comes next: in this case certainly we may be
deceived; for while the perception that there is white before us cannot
be false, the perception that what is white is this or that may be
false. (3) Third comes the perception of the universal attributes which
accompany the concomitant objects to which the special sensibles attach
(I mean e.g. of movement and magnitude); it is in respect of these that
the greatest amount of sense-illusion is possible.\"(Book III,
428b)`</font>`{=html}

Imagination, according to this model, lays out things in the senses.

## Galen

The \'physicians\' (most especially Galen) incorporated ideas from the
Hippocractics and from Plato into a view in which 3 (or more) inner
senses---most basically memory, estimation, and imagination---were
associated with 3 ventricles in the brain.

*This is a **stub** that needs further expansion*.

## Homer (c. 800-900 BC) The *Iliad* and *Odyssey*

Odyssey

!HomerPanpsychism and
panexperientialism can be traced to, at least, Homer\'s Iliad. Just
reading the book allows us to experience what a different focus of
consciousness feels like. It is a way of being, being a Homeric Greek,
thus distinct from being a modern man. Both states of consciousness
result in different ways of experiencing the world.

As we read the Iliad, we are drawn into the book through the images it
creates in us and the feelings it evokes in us through the meter and the
language. The reader becomes the book. \"The reader became the book, and
the summer night was like the conscious being of the book\" (Wallace
Stevens). That experience of becoming the book, of losing yourself in
the book, is the experience of a different aspect of consciousness,
being a Homeric Greek.

Homer frequently ascribes even our emotions to the world around us. The
ancients do not just fear but fear grips them, for example: \"So spake
Athene, and pale fear gat hold of them all. The arms flew from their
hands in their terror and fell all upon the ground, as the goddess
uttered her voice\" (Odyssey book XXIV).

The German classicist Bruno Snell, in *The Discovery of the Mind*
provides us with \"a convincing account of the enormous change in \...
human personality which took place during the centuries covered by Homer
(to) Socrates.\"(The London Times Literary Supplement). Snell\'s book
establishes two distinct aspects of consciousness. He says, \"The
experience of Homer differs from our own\" (p.v); \"For Homer, psyche is
the force which keeps the human being alive\...\"(p. 8). When the psyche
leaves, the owner loses consciousness. The Homeric *psyche* is where
pan-psychism originates. It begins in a conception of consciousness as a
force that is separate from the body. Snell compares Homer to the
tragedy of Orestes, which focuses on the individual. \"Homer
concentrates on the action (process) and the situation in preference to
the agent\...\"(p. 211) Orestes is in a different state of
consciousness, \"a new state of consciousness\"(p. 211).

## Plato (427-347 BC)

The Republic <http://www.constitution.org/pla/repub_00.htm> Especially
book VI <http://www.constitution.org/pla/repub_06.htm> and book VII (the
Cave) <http://www.constitution.org/pla/repub_07.htm>

!PlatoPlato\'s most interesting contributions to
consciousness studies are in book VI of *The Republic*. His idea of the
mind is illustrated below.

![](Constudplato.png "Constudplato.png")

He believes that light activates pre-existing capabilities in the eyes:

`<font face="times new roman">`{=html}\"Sight being, as I conceive, in
the eyes, and he who has eyes wanting to see; color being also present
in them, still unless there be a third nature specially adapted to the
purpose, the owner of the eyes will see nothing and the colors will be
invisible.\"`</font>`{=html}

However, it is in the metaphor of **the divided line** that Plato
introduces a fascinating account of the relationships and properties of
things. He points out that analysis deals in terms of the relationships
of pure forms:

`<font face="times new roman">`{=html}\"And do you not know also that
although they make use of the visible forms and reason about them, they
are thinking not of these, but of the ideals which they resemble; not of
the figures which they draw, but of the absolute square and the absolute
diameter, and so on \-- the forms which they draw or make, and which
have shadows and reflections in water of their own, are converted by
them into images, but they are really seeking to behold the things
themselves, which can only be seen with the eye of the
mind?\"`</font>`{=html}

Notice how he introduces the notion of a mind\'s eye observing mental
content arranged as geometrical forms. He proposes that through this
mode of ideas we gain understanding:

`<font face="times new roman">`{=html}\"And the habit which is concerned
with geometry and the cognate sciences I suppose that you would term
understanding, and not reason, as being intermediate between opinion and
reason.\"`</font>`{=html}

However, the understanding can also contemplate knowledge:

`<font face="times new roman">`{=html}\"..I understand you to say that
knowledge and being, which the science of dialectic contemplates, are
clearer than the notions of the arts, as they are termed, which proceed
from hypotheses only: these are also contemplated by the understanding,
and not by the senses: yet, because they start from hypotheses and do
not ascend to a principle, those who contemplate them appear to you not
to exercise the higher reason upon them, although when a first principle
is added to them they are cognizable by the higher reason.
\"`</font>`{=html}

Plato\'s work is not usually discussed in this way but is extended to
universals such as the idea of the colour red as a universal that can be
applied to many specific instances of things.

In \"Plato\'s Cave\" (Book VII) Plato describes how experience could be
some transfer from or copy of real things rather than the things
themselves:

!Plato\'s
Cave`<font face="times new roman">`{=html}\"And
now, I said, let me show in a figure how far our nature is enlightened
or unenlightened: --- Behold! human beings living in a underground den,
which has a mouth open towards the light and reaching all along the den;
here they have been from their childhood, and have their legs and necks
chained so that they cannot move, and can only see before them, being
prevented by the chains from turning round their heads. Above and behind
them a fire is blazing at a distance, and between the fire and the
prisoners there is a raised way; and you will see, if you look, a low
wall built along the way, like the screen which marionette players have
in front of them, over which they show the puppets.`</font>`{=html}

`<font face="times new roman">`{=html}I see.`</font>`{=html}

`<font face="times new roman">`{=html}And do you see, I said, men
passing along the wall carrying all sorts of vessels, and statues and
figures of animals made of wood and stone and various materials, which
appear over the wall? Some of them are talking, others
silent.`</font>`{=html}

`<font face="times new roman">`{=html}You have shown me a strange image,
and they are strange prisoners.`</font>`{=html}

`<font face="times new roman">`{=html}Like ourselves, I replied; and
they see only their own shadows, or the shadows of one another, which
the fire throws on the opposite wall of the cave?`</font>`{=html}

`<font face="times new roman">`{=html}True, he said; how could they see
anything but the shadows if they were never allowed to move their
heads?`</font>`{=html}

`<font face="times new roman">`{=html}And of the objects which are being
carried in like manner they would only see the shadows?`</font>`{=html}

`<font face="times new roman">`{=html}Yes, he said.`</font>`{=html}

`<font face="times new roman">`{=html}And if they were able to converse
with one another, would they not suppose that they were naming what was
actually before them?`</font>`{=html}

`<font face="times new roman">`{=html}Very true.`</font>`{=html}

`<font face="times new roman">`{=html}And suppose further that the
prison had an echo which came from the other side, would they not be
sure to fancy when one of the passers-by spoke that the voice which they
heard came from the passing shadow?`</font>`{=html}

`<font face="times new roman">`{=html}No question, he
replied.`</font>`{=html}

`<font face="times new roman">`{=html}To them, I said, the truth would
be literally nothing but the shadows of the images.`</font>`{=html}

`<font face="times new roman">`{=html}That is certain.`</font>`{=html}

`<font face="times new roman">`{=html}And now look again, and see what
will naturally follow it, the prisoners are released and disabused of
their error. At first, when any of them is liberated and compelled
suddenly to stand up and turn his neck round and walk and look towards
the light, he will suffer sharp pains; the glare will distress him, and
he will be unable to see the realities of which in his former state he
had seen the shadows; and then conceive some one saying to him, that
what he saw before was an illusion, but that now, when he is approaching
nearer to being and his eye is turned towards more real existence, he
has a clearer vision, --- what will be his reply? And you may further
imagine that his instructor is pointing to the objects as they pass and
requiring him to name them, --- will he not be perplexed? Will he not
fancy that the shadows which he formerly saw are truer than the objects
which are now shown to him?\"`</font>`{=html}

This early intuition of information theory predates Aristotle\'s concept
of the transfer of states from one place to another.

## Parmenides (c. 480 BC) *On Nature*

## Siddhartha Gautama (c. 500 BC) Buddhist Texts

!BuddhaSiddhartha 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 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 meditator 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).

**The Immaterial Jhanas**

The first four jhanas will be familiar from earlier, Hindu meditational
techniques. 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.

**Further reading**

The Buddhist Publication Society. Especially: The Jhanas In Theravada
Buddhist Meditation by Henepola Gunaratana. The Wheel Publication No.
351/353 . 1988 Buddhist Publication
Society. <http://www.accesstoinsight.org/lib/bps/index.html>


# Consciousness Studies/Medieval Concepts

It is sometimes said that before the 17th century, there was no
distinction between conscience and consciousness (both being referenced
by the same Latin word \'conscius---from \'conscientia\'). One feature
of the soul being its ability to know itself, and the soul being
witnessed also by God, there was a sense in which conscience was a
knowledge of the inner life shared with God. In fact, Boris Hennig [^1]
proposes that Descartes did not invent an entirely new sense of
conscience, but if anything adapted this Augustinian sense of the term.
The Augustinians themselves can be said to have adapted this use of
conscius from the Latin Stoics like Seneca. On the other hand the
Ancient Greek philosophers were clear that there was a problem of mind
and the work of Descartes can be seen as more directly connected with
Aristotle rather than with medieval philosophy.

## References

[^1]: \"Cartesian Conscientia\", *British Journal for the History of
    Philosophy* 15(3) 2007: 455 -- 484.