Solipsism ( (listen); from Latin solus, meaning
'alone', and ipse, meaning 'self') is the
philosophical idea that only one's own mind
is sure to exist.
As an epistemological position, solipsism
holds that knowledge of anything outside one's
own mind is unsure; the external world and
other minds cannot be known and might not
exist outside the mind.
As a metaphysical position, solipsism goes
further to the conclusion that the world and
other minds do not exist.
This extreme position is claimed to be irrefutable,
as the solipsist believes themself to be the
only true authority, all others being creations
of their own mind.
== Varieties ==
There are varying degrees of solipsism that
parallel the varying degrees of skepticism:
=== Metaphysical solipsism ===
Metaphysical solipsism is a variety of solipsism.
Based on a philosophy of subjective idealism,
metaphysical solipsists maintain that the
self is the only existing reality and that
all other realities, including the external
world and other persons, are representations
of that self, and have no independent existence.
There are several versions of metaphysical
solipsism, such as Caspar Hare's egocentric
presentism (or perspectival realism), in which
other people are conscious, but their experiences
are simply not present.
=== Epistemological solipsism ===
Epistemological solipsism is the variety of
idealism according to which only the directly
accessible mental contents of the solipsistic
philosopher can be known.
The existence of an external world is regarded
as an unresolvable question rather than actually
false.
Further, one cannot also be certain as to
what extent the external world exists independently
of one's mind.
For instance, it may be that a God-like being
controls the sensations received by one's
brain, making it appear as if there is an
external world when most of it (excluding
the God-like being and oneself) is false.
However, the point remains that epistemological
solipsists consider this an "unresolvable"
question.
=== Methodological solipsism ===
Methodological solipsism is an agnostic variant
of solipsism.
It exists in opposition to the strict epistemological
requirements for "knowledge" (e.g. the requirement
that knowledge must be certain).
It still entertains the points that any induction
is fallible.
Methodological solipsism sometimes goes even
further to say that even what we perceive
as the brain is actually part of the external
world, for it is only through our senses that
we can see or feel the mind.
Only the existence of thoughts is known for
certain.
Importantly, methodological solipsists do
not intend to conclude that the stronger forms
of solipsism are actually true.
They simply emphasize that justifications
of an external world must be founded on indisputable
facts about their own consciousness.
The methodological solipsist believes that
subjective impressions (empiricism) or innate
knowledge (rationalism) are the sole possible
or proper starting point for philosophical
construction.
Often methodological solipsism is not held
as a belief system, but rather used as a thought
experiment to assist skepticism (e.g. Descartes'
Cartesian skepticism).
== Main points ==
Denial of material existence, in itself, does
not constitute solipsism.
A feature of the metaphysical solipsistic
worldview is the denial of the existence of
other minds.
Since personal experiences are private and
ineffable, another being's experience can
be known only by analogy.
Philosophers try to build knowledge on more
than an inference or analogy.
The failure of Descartes' epistemological
enterprise brought to popularity the idea
that all certain knowledge may go no further
than "I think; therefore I exist" without
providing any real details about the nature
of the "I" that has been proven to exist.The
theory of solipsism also merits close examination
because it relates to three widely held philosophical
presuppositions, each itself fundamental and
wide-ranging in importance:
My most certain knowledge is the content of
my own mind—my thoughts, experiences, affects,
etc.
There is no conceptual or logically necessary
link between mental and physical—between,
say, the occurrence of certain conscious experience
or mental states and the 'possession' and
behavioral dispositions of a 'body' of a particular
kind.
The experience of a given person is necessarily
private to that person.To expand on point
2 a little further, the conceptual problem
here is that the previous assumes mind or
consciousness (which are attributes) can exist
independent of some entity having this capability,
i.e., that an attribute of an existent can
exist apart from the existent itself.
If one admits to the existence of an independent
entity (e.g., your brain) having that attribute,
the door is open.
(See the Brain in a vat.)
Some people hold that, while it cannot be
proven that anything independent of one's
mind exists, the point that solipsism makes
is irrelevant.
This is because, whether the world as we perceive
it exists independently or not, we cannot
escape this perception (except via death),
hence it is best to act assuming that the
world is independent of our minds.
For example, if one committed a crime, one
is likely to be punished, causing potential
distress to oneself even if the world was
not independent of one's mind; therefore,
it is in one's best interests and is most
convenient to assume the world exists independently
of one's mind.There is also the issue of plausibility
to consider.
If one is the only mind in existence, then
one is maintaining that one's mind alone created
all of which one is apparently aware.
This includes the symphonies of Beethoven,
the works of Shakespeare, all of mathematics
and science (which one can access via one's
phantom libraries), etc.
Critics of solipsism find this somewhat implausible.
However, since, for example, people are able
to construct entire worlds inside their minds
while having dreams when asleep, and people
have had dreams which included things such
as music of Beethoven or the works of Shakespeare
or math or science in them, solipsists do
have counter-arguments to justify their views
being plausible.
== History ==
=== Gorgias ===
Solipsism was first recorded by the Greek
presocratic sophist, Gorgias (c. 483–375
BC) who is quoted by the Roman sceptic Sextus
Empiricus as having stated:
Nothing exists.
Even if something exists, nothing can be known
about it.
Even if something could be known about it,
knowledge about it can't be communicated to
others.Much of the point of the Sophists was
to show that "objective" knowledge was a literal
impossibility.
(See also comments credited to Protagoras
of Abdera).
=== Descartes ===
The foundations of solipsism are in turn the
foundations of the view that the individual's
understanding of any and all psychological
concepts (thinking, willing, perceiving, etc.)
is accomplished by making an analogy with
his or her own mental states; i.e., by abstraction
from inner experience.
And this view, or some variant of it, has
been influential in philosophy since Descartes
elevated the search for incontrovertible certainty
to the status of the primary goal of epistemology,
whilst also elevating epistemology to "first
philosophy".
=== Berkeley ===
George Berkeley's arguments against materialism
in favour of idealism provide the solipsist
with a number of arguments not found in Descartes.
While Descartes defends ontological dualism,
thus accepting the existence of a material
world (res extensa) as well as immaterial
minds (res cogitans) and God, Berkeley denies
the existence of matter but not minds, of
which God is one.
== Relation to other ideas ==
=== 
Idealism and materialism ===
One of the most fundamental debates in philosophy
concerns the "true" nature of the world—whether
it is some ethereal plane of ideas or a reality
of atomic particles and energy.
Materialism posits a real 'world out there,'
as well as in and through us, that can be
sensed—seen, heard, tasted, touched and
felt, sometimes with prosthetic technologies
corresponding to human sensing organs.
(Materialists do not claim that human senses
or even their prosthetics can, even when collected,
sense the totality of the 'universe'; simply
that what they collectively cannot sense cannot
in any way be known to us.)
Materialists do not find this a useful way
of thinking about the ontology and ontogeny
of ideas, but we might say that from a materialist
perspective pushed to a logical extreme communicable
to an idealist (an "Away Team" perspective),
ideas are ultimately reducible to a physically
communicated, organically, socially and environmentally
embedded 'brain state'.
While reflexive existence is not considered
by materialists to be experienced on the atomic
level, the individual's physical and mental
experiences are ultimately reducible to the
unique tripartite combination of environmentally
determined, genetically determined, and randomly
determined interactions of firing neurons
and atomic collisions.
As a correlative, the only thing that dreams
and hallucinations prove are that some neurons
can reorganize and 'clean house' 'on break'
(often reforming according to emergent, prominent,
or uncanny cultural themes), misfire, and
malfunction.
But for materialists, ideas have no primary
reality as essences separate from our physical
existence.
From a materialist "Home Team" perspective,
ideas are also social (rather than purely
biological), and formed and transmitted and
modified through the interactions between
social organisms and their social and physical
environments.
This materialist perspective informs scientific
methodology, insofar as that methodology assumes
that humans have no access to omniscience
and that therefore human knowledge is an ongoing,
collective enterprise that is best produced
via scientific and logical conventions adjusted
specifically for material human capacities
and limitations.Modern Idealists, on the other
hand, believe that the mind and its thoughts
are the only true things that exist.
This is the reverse of what is sometimes called
classical idealism or, somewhat confusingly,
Platonic idealism due to the influence of
Plato's Theory of Forms (εἶδος eidos
or ἰδέα idea) which were not products
of our thinking.
The material world is ephemeral, but a perfect
triangle or "beauty" is eternal.
Religious thinking tends to be some form of
idealism, as God usually becomes the highest
ideal (such as Neoplatonism).
On this scale, solipsism can be classed as
idealism.
Thoughts and concepts are all that exist,
and furthermore, only the solipsist's own
thoughts and consciousness exist.
The so-called "reality" is nothing more than
an idea that the solipsist has (perhaps unconsciously)
created.
=== Cartesian dualism ===
There is another option: the belief that both
ideals and "reality" exist.
Dualists commonly argue that the distinction
between the mind (or 'ideas') and matter can
be proven by employing Leibniz' principle
of the identity of indiscernibles which states
that if two things share exactly the same
qualities, then they must be identical, as
in indistinguishable from each other and therefore
one and the same thing.
Dualists then attempt to identify attributes
of mind that are lacked by matter (such as
privacy or intentionality) or vice versa (such
as having a certain temperature or electrical
charge).
One notable application of the identity of
indiscernibles was by René Descartes in his
Meditations on First Philosophy.
Descartes concluded that he could not doubt
the existence of himself (the famous cogito
ergo sum argument), but that he could doubt
the (separate) existence of his body.
From this, he inferred that the person Descartes
must not be identical to the Descartes body
since one possessed a characteristic that
the other did not: namely, it could be known
to exist.
Solipsism agrees with Descartes in this aspect,
and goes further: only things that can be
known to exist for sure should be considered
to exist.
The Descartes body could only exist as an
idea in the mind of the person Descartes.
Descartes and dualism aim to prove the actual
existence of reality as opposed to a phantom
existence (as well as the existence of God
in Descartes' case), using the realm of ideas
merely as a starting point, but solipsism
usually finds those further arguments unconvincing.
The solipsist instead proposes that his/her
own unconscious is the author of all seemingly
"external" events from "reality".
=== Philosophy of Schopenhauer ===
The World as Will and Representation is the
central work of Arthur Schopenhauer.
Schopenhauer saw the human will as our one
window to the world behind the representation,
the Kantian thing-in-itself.
He believed, therefore, that we could gain
knowledge about the thing-in-itself, something
Kant said was impossible, since the rest of
the relationship between representation and
thing-in-itself could be understood by analogy
as the relationship between human will and
human body.
=== Idealism ===
The idealist philosopher George Berkeley argued
that physical objects do not exist independently
of the mind that perceives them.
An item truly exists only as long as it is
observed; otherwise, it is not only meaningless
but simply nonexistent.
The observer and the observed are one.
Berkeley does attempt to show things can and
do exist apart from the human mind and our
perception, but only because there is an all-encompassing
Mind in which all "ideas" are perceived – in
other words, God, who observes all.
Solipsism agrees that nothing exists outside
of perception, but would argue that Berkeley
falls prey to the egocentric predicament – he
can only make his own observations, and thus
cannot be truly sure that this God or other
people exist to observe "reality".
The solipsist would say it is better to disregard
the unreliable observations of alleged other
people and rely upon the immediate certainty
of one's own perceptions.
=== Rationalism ===
Rationalism is the philosophical position
that truth is best discovered by the use of
reasoning and logic rather than by the use
of the senses (see Plato's theory of Forms).
Solipsism is also skeptical of sense-data.
=== 
Philosophical zombie ===
The theory of solipsism crosses over with
the theory of the philosophical zombie in
that all other seemingly conscious beings
actually lack true consciousness, instead
they only display traits of consciousness
to the observer, who is the only conscious
being there is.
=== Falsifiability and testability ===
Solipsism is not a falsifiable hypothesis
as described by Karl Popper or Imre Lakatos:
there does not seem to be an imaginable disproof.One
critical test is nevertheless to consider
the induction from experience that the externally
observable world does not seem, at first approach,
to be directly manipulable purely by mental
energies alone.
One can indirectly manipulate the world through
the medium of the physical body, but it seems
impossible to do so through pure thought (e.g.
via psychokinesis).
It might be argued that if the external world
were merely a construct of a single consciousness,
i.e. the self, it could then follow that the
external world should be somehow directly
manipulable by that consciousness, and if
it is not, then solipsism is false.
An argument against this states the notion
that such manipulation may be possible but
barred from the conscious self via the subconscious
self, a 'locked' portion of the mind that
is still nevertheless the same mind.
Lucid dreaming might be considered an example
of when these locked portions of the subconscious
become accessible.
An argument against this might be brought
up in asking why the subconscious mind would
be locked.
Also, the access to the autonomous ('locked')
portions of the mind during the lucid dreaming
is obviously much different (for instance:
is relatively more transient) than the access
to autonomous regions of the perceived nature.
The method of the typical scientist is materialist:
they first assume that the external world
exists and can be known.
But the scientific method, in the sense of
a predict-observe-modify loop, does not require
the assumption of an external world.
A solipsist may perform a psychological test
on themselves, to discern the nature of the
reality in their mind - however David Deutsch
uses this fact to counter-argue: "outer parts"
of solipsist, behave independently so they
are independent for "narrowly" defined (conscious)
self.
A solipsist's investigations may not be proper
science, however, since it would not include
the co-operative and communitarian aspects
of scientific inquiry that normally serve
to diminish bias.
=== Minimalism ===
Solipsism is a form of logical minimalism.
Many people are intuitively unconvinced of
the nonexistence of the external world from
the basic arguments of solipsism, but a solid
proof of its existence is not available at
present.
The central assertion of solipsism rests on
the nonexistence of such a proof, and strong
solipsism (as opposed to weak solipsism) asserts
that no such proof can be made.
In this sense, solipsism is logically related
to agnosticism in religion: the distinction
between believing you do not know, and believing
you could not have known.
However, minimality (or parsimony) is not
the only logical virtue.
A common misapprehension of Occam's Razor
has it that the simpler theory is always the
best.
In fact, the principle is that the simpler
of two theories of equal explanatory power
is to be preferred.
In other words: additional "entities" can
pay their way with enhanced explanatory power.
So the realist can claim that, while his world
view is more complex, it is more satisfying
as an explanation.
=== Solipsism in infants ===
Some developmental psychologists believe that
infants are solipsistic, and that eventually
children infer that others have experiences
much like theirs and reject solipsism.
=== Hinduism ===
The earliest reference to Solipsism in Hindu
philosophy is found in the Brihadaranyaka
Upanishad, dated to early 1st millennium BCE.
The Upanishad holds the mind to be the only
god and all actions in the universe are thought
to be a result of the mind assuming infinite
forms.
After the development of distinct schools
of Indian philosophy, Advaita Vedanta and
Samkhya schools are thought to have originated
concepts similar to solipsism.
==== Advaita Vedanta ====
Advaita is one of the six most known Hindu
philosophical systems and literally means
"non-duality".
Its first great consolidator was Adi Shankaracharya,
who continued the work of some of the Upanishadic
teachers, and that of his teacher's teacher
Gaudapada.
By using various arguments, such as the analysis
of the three states of experience—wakefulness,
dream, and deep sleep, he established the
singular reality of Brahman, in which Brahman,
the universe and the Atman or the Self, were
one and the same.
One who sees everything as nothing but the
Self, and the Self in everything one sees,
such a seer withdraws from nothing.
For the enlightened, all that exists is nothing
but the Self, so how could any suffering or
delusion continue for those who know this
oneness?
The concept of the Self in the philosophy
of Advaita could be interpreted as solipsism.
However, the transhuman, theological implications
of the Self in Advaita protect it from true
solipsism as found in the west.
Similarly, the Vedantic text Yogavasistha,
escapes charge of solipsism because the real
"I" is thought to be nothing but the absolute
whole looked at through a particular unique
point of interest.Advaita is also thought
to strongly diverge from solipsism in that,
the former is a system of exploration of one's
mind in order to finally understand the nature
of the self and attain complete knowledge.
The unity of existence is said to be directly
experienced and understood at the end as a
part of complete knowledge.
On the other hand, solipsism posits the non-existence
of the external void right at the beginning,
and says that no further inquiry is possible.
==== Samkhya and Yoga ====
Samkhya philosophy, which is sometimes seen
as the basis of Yogic thought, adopts a view
that matter exists independently of individual
minds.
Representation of an object in an individual
mind is held to be a mental approximation
of the object in the external world.
Therefore, Samkhya chooses representational
realism over epistemological solipsism.
Having established this distinction between
the external world and the mind, Samkhya posits
the existence of two metaphysical realities
Prakriti (matter) and Purusha (consciousness).
=== Buddhism ===
Some misinterpretations of Buddhism assert
that external reality is an illusion, and
sometimes this position is [mis]understood
as metaphysical solipsism.
Buddhist philosophy, though, generally holds
that the mind and external phenomena are both
equally transient, and that they arise from
each other.
The mind cannot exist without external phenomena,
nor can external phenomena exist without the
mind.
This relation is known as "dependent arising"
(pratityasamutpada).
The Buddha stated, "Within this fathom long
body is the world, the origin of the world,
the cessation of the world and the path leading
to the cessation of the world".
Whilst not rejecting the occurrence of external
phenomena, the Buddha focused on the illusion
created within the mind of the perceiver by
the process of ascribing permanence to impermanent
phenomena, satisfaction to unsatisfying experiences,
and a sense of reality to things that were
effectively insubstantial.
Mahayana Buddhism also challenges the illusion
of the idea that one can experience an 'objective'
reality independent of individual perceiving
minds.
From the standpoint of Prasangika (a branch
of Madhyamaka thought), external objects do
exist, but are devoid of any type of inherent
identity: "Just as objects of mind do not
exist [inherently], mind also does not exist
[inherently]".
In other words, even though a chair may physically
exist, individuals can only experience it
through the medium of their own mind, each
with their own literal point of view.
Therefore, an independent, purely 'objective'
reality could never be experienced.
The Yogacara (sometimes translated as "Mind
only") school of Buddhist philosophy contends
that all human experience is constructed by
mind.
Some later representatives of one Yogacara
subschool (Prajnakaragupta, Ratnakīrti) propounded
a form of idealism that has been interpreted
as solipsism.
A view of this sort is contained in the 11th-century
treatise of Ratnakirti, "Refutation of the
existence of other minds" (Santanantara dusana),
which provides a philosophical refutation
of external mind-streams from the Buddhist
standpoint of ultimate truth (as distinct
from the perspective of everyday reality).In
addition to this, the Bardo Thodol, Tibet's
famous book of the dead, repeatedly states
that all of reality is a figment of one's
perception, although this occurs within the
"Bardo" realm (post-mortem).
For instance, within the sixth part of the
section titled "The Root Verses of the Six
Bardos", there appears the following line:
"May I recognize whatever appeareth as being
mine own thought-forms"; there are many lines
in similar ideal.
== See also ==
== Notes
