English

Adjective

1. of, relating to, or being solipsism

Quotations

• 1986, David Leavitt, The Lost Language of Cranes, Penguin, paperback edition, page 73

  For Philip there was only this solipsistic stroking, by definition nameless.

Solipsism (Latin: solus, alone + ipse, self) is the philosophical idea that "My mind is the only thing that I know exists." Solipsism is an epistemological or metaphysical position that knowledge of anything outside the mind is unjustified. The external world and other minds cannot be known and might not exist. In the history of philosophy, solipsism has served as a skeptical hypothesis.

Explanation

Denial of the materialist existence, in itself, is not enough to be a solipsist. Possibly the most controversial feature of the solipsistic world view is the denial of the existence of other minds. We can never directly know another's mental stability. Qualia, or personal experience, are private and incorrigible. Another person's experience can be known only by analogy.

Philosophers try to build knowledge on more than an inference or analogy. The failure of Descartes's epistemological enterprise brought to popularity the idea that all certain knowledge may end at "I think therefore I am" (cogito ergo sum).

The theory of solipsism also merits close examination because it relates to three widely held philosophical presuppositions, which are themselves fundamental and wide-ranging in importance. These are:

1. That my most certain knowledge is the contents of my own mind — my thoughts, experiences, affects, etc.
2. That there is no conceptual or logically necessary link between the mental and the physical — between, say, the occurrence of certain conscious experiences or mental states and the 'possession' and behavioral dispositions of a 'body' of a particular kind (see the Brain in a vat);
3. That the experiences of a given person are necessarily private to that person.

Solipsism is not a single concept but instead refers to several world views whose common element is some form of denial of the existence of a universe independent from the mind of the agent.

History

Gorgias

Solipsism is first recorded with the Greek presocratic sophist, Gorgias (c. 483–375 BC) who is quoted by the Roman skeptic Sextus Empiricus as having stated:

1. Nothing exists;
2. Even if something exists, nothing can be known about it; and
3. Even if something could be known about it, knowledge about it can't be communicated to others.

Descartes

The foundations of solipsism lie at the heart of the view that the individual understands all psychological concepts (thinking, willing, perceiving, etc.) by 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". However, both these manoeuvres — methodological solipsism and the primacy of epistemology — have been called into question in modern times, with Richard Rorty making particularly pointed criticisms in Philosophy and the Mirror of Nature.

Varieties

Metaphysical solipsism

Metaphysical solipsism is the variety of idealism which maintains that the individual self of the solipsistic philosopher is the whole of reality and that the external world and other persons are representations of that self having no independent existence (Wood, 295).

Epistemological solipsism

see 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, or an unnecessary hypothesis rather than actually false.

Methodological solipsism

Methodological solipsism is the epistemological thesis that the individual self and its states are the sole possible or proper starting point for philosophical construction (Wood, 295). The methodological solipsist does not intend to conclude that one of the stronger forms of solipsism is true, but rather believes that all other truths must be founded on indisputable facts about his own consciousness. A skeptical turn along these lines is cartesian skepticism.

Psychology, and psychiatry

Philosophical solipsism as pathological

Solipsism is often introduced (for example "Philosophy made simple", by Popkin and Stroll) as a bankrupt philosophy, or at best bizarre and unlikely. Alternatively, the philosophy is introduced in the context of relating it to pathological psychological conditions. However, solipsists believe that the philosophy of solipsism is neither bankrupt, bizarre, nor pathological.

Solipsism syndrome

Solipsism syndrome is a pathological psychiatric condition involving dissociative mental states. It is only incidentally related to philosophical solipsism. Solipsists assert that the lack of ability to prove the existence of other minds does not, in itself, cause the psychiatric condition of detachment from reality. The feeling of detachment from reality is unaffected by the answer to the question of whether the common-sense universe exists or not.

Infant solipsism

Developmental psychologists commonly believe that infants are solipsist, and that eventually children infer that others have experience much like theirs and reject solipsism (see Infant metaphysics). Solipsists assert that this rejection is not logically justified.

Questions

Consequences

To discuss consequences clearly, an alternative is required: solipsism as opposed to what? As opposed to not solipsism is not sufficient. The most natural alternative is materialism . Materialism in a minimal sense, that there is an external universe is most likely not observationally distinct from solipsism. Thus at this level the consequences of solipsism as opposed to materialism are purely psychological. However, materialism is often bundled with a principle of physical locality, that an event on one side of the galaxy can only affect an event on the other side through the action of some sequence of cause and effect that traveled across the gap. Quantum mechanics and the EPR paradox thought experiments have been used to suggest non-locality, which for some suggest a challenge to the materialist point of view.

One consequence that is inherent to solipsism is an atomic individualist view of the world and nature. If only I matter, then other people, animals, environments only matter insofar as they impact myself. This may be an anti-social philosophy. Language and other social mediums are taken for granted as self conceived and inherent. Maintenance of these social tools is not required, the individual need only exist, not interact with the world. Sincere solipsists are unlikely to be persuaded by such considerations; believing society to be non-existent, there is no question of being "anti social" for them.

The American eastern philosopher Alan Watts wrote extensively about this subject; a video snippet can be watched here.

Plausible?

Solipsism is the position that only perception exists. The question of plausibility depends, of course, on the philosophical groundwork one chooses to use as a starting point. Historically, Western philosophical systems have been somewhat at odds with Eastern modes of thought, and solipsism as formulated in the context of many Eastern philosophies is not seen as problematic by its practitioners (see the section Eastern Philosophies, below).

A general (Western) discussion stemming from, for example, an objectivist philosophical groundwork, can be viewed as considering whether an idea stands up to common sense or arguments of reasonableness, and is free from obvious internal logical contradictions. Solipsism is suspect on at least two grounds, in this case.

1. Can one's perception, within one's mind exist without an external something to exist in, such as a biological brain?
2. Does one consider all of perceptual reality as part of one's faculty of being, such as high math, music composition and other creative work which one can not consciously re-produce?
3. An objection could be termed a corollary to the two above. It asks a question about the functioning of one's personal perceptions. The solipsist cannot deny the fact that he thinks, thus going through reasoning processes about his perceptions. His consciousness is not just perceptions; it's also thinking about them. How is this possible without some mental machinery which can perform such thinking? But if such mental machinery exists independent and apart from his perceptions, this also contradicts the "perceptions only" premise. Otherwise a solipsist can define his consciousness to contain perception and thinking processes together.

Note, however, that there is a potential refutation to the thesis that 'perception' requires 'thinking.' If the solipsist were merely being created instantaneously from moment to moment with all memory intact and updated, he would only think he is 'thinking' — i.e., have a perception of thinking. In fact, no operation or activity has truly taken place from percept to percept (think of how the 'still' frames of a moving picture film strip blend into the appearance of motion) — only the passage of time. But such a refutation is very vulnerable to the objection based on language (e.g. the private language argument). A solipsist who declares that he is not really thinking cannot hold that he is really speaking.

A subjective argument for the implausibility of solipsism is that it goes against the commonly observed tendency for sane adult humans in the western world to interpret the world as external and existing independent of themselves. This attitude, not always held by children, is listed by developmental psychologists as one of the signs of the maturing mind. The principle is deeply held, and well integrated with human languages and other thought processes. However, that humans think this way, even if they must think this way, does not prove something true.

A strong argument for the plausibility of solipsism is the semantics of existence. If something can never affect you, never, in any way, then in what sense can it be said to exist? Does the moon exist? Does the moon itself right now affect you in any way? The light from it affects you, and the gravity field affects you – but the moon itself does not. This is a major splitting point. Non-solipsists will often take a demonstration of an effect of the moon's gravity field as supporting evidence for the existence of the moon while a solipsist takes it as supporting evidence only of the existence of the moon's gravity field and light, which they perceive. This view conflicts with the classic scientific approach which posits cause and effect interaction between all the parts of reality over time to create the world we observe, even if we personally only observe a small part of it.

Neuroscience

Empirical studies of the human brain suggest that the human mind is subject to many strongly held miscomprehensions of what is held by consensus to be the external and objective world. This line of thought could be extended to the claim that even if the external world is supposed to exist, the private mental world of each agent is logically that of the solipsist. A thought experiment emphasizes this point. Imagine you are in a fight to the death: If your opponent loses, will the sun rise tomorrow? Almost all people would say yes, but if you lose, will the sun rise tomorrow? The thought experiment suggests that it is not true for any agent that all minds are on an equal footing. The principle that they are is an abstraction that ignores a very important detail in the private mental life of the agent. This idea is expressed in more detail in What Is it Like to Be a Bat?, by Thomas Nagel (in, for example, The Mind's I by Douglas Hofstadter).

This argument exposes a misunderstanding which constantly recurs with regard to solipsism. If it borrows a conclusion drawn from the scientific investigation of the external world, only to pull the rug from under the scientific enterprise by declaring that there is no external world, then since the solipsist is at least uncertain that brains exist, how can he draw conclusions about his mind from them? Solipsists claim that the method is proof by contradiction. If the external world does not exist, it does not exist. On the other hand if it is assumed to exist, and studied with neuroscience, it is found that the causal chains involved in perception are indirect. Solipsists paraphrase "the external world is only known indirectly" as "the external world cannot be known at all", and thereby conclude that the external world is either nonexistent or unknowable. However, "the external world cannot be known at all" is not a corollary or implication of "the external world is only known indirectly", and no scientist would make assumption. Almost everybody considers science as posited on the investigation of the external world.

Last surviving soul

Would the last person left alive after a nuclear holocaust be a solipsist? Not necessarily, because for the solipsist, it is not merely the case that they believe that their thoughts, experiences, and emotions are, as a matter of contingent fact, the only thoughts, experiences, and emotions that can be. Rather, the solipsist can attach no meaning to the supposition that there could be thoughts, experiences, and emotions other than their own — that events may occur or objects or people exist independently of the solipsist's own experiences. In short, the metaphysical solipsist understands the word "pain" [i.e., someone else's], for example, to mean "one's own pain" — but this word cannot accordingly be construed to apply in any sense other than this exclusively egocentric, non-empathetic 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 atoms and energy. Materialism posits a separate 'world out there' that can be touched and felt, with the separate individual's physical and mental experiences reducible to the collisions of atoms and the interactions of firing neurons. The only thing that dreams and hallucinations prove are that some neurons can misfire and malfunction, but there is no fundamental reality behind an idea except as a brain-state. Idealists, on the other hand, believe that the mind and its thoughts are the only true things that exist. This doctrine is often called Platonism after its most famous proponent. The material world is ephemeral, but a perfect triangle or "love" 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, specifically subjective idealism. Thoughts and concepts are all that exist, and furthermore, only 'my' 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, of course: 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's principle of the identity of indiscernibles. This states that two things are identical if, and only if, they share exactly the same qualities, that is, are indistinguishable. 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's case), using the realm of ideas merely as a starting point, but solipsism usually finds those further arguments unconvincing. The solipsist instead proposes that their own unconscious is the author of all seemingly "external" events from "reality".

Radical empiricism

The idealist philosopher George Berkeley argued that so-called physical objects do not exist independently of the so-called mind that perceives them. An item truly exists only so 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. The solipsist appreciates the fact that nothing exists outside of perception, but would further point out that Berkeley falls prey to the egocentric predicament - he can only make his own observations, and can't be truly sure that this God or other people exist to observe "reality". The solipsist would say it is better to disregard the unreliable possible 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, which holds a similar distrust for sense-data, is thus related to rationalism, and in fact may be seen as a form of extreme rationalism.

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

Falsifiability in the sense of Popper or Lakatos is not a simple principle. If an agent discovers a contradiction in their own terms within their own thoughts then there is an error, but exactly which component of the mind is at fault is not clear: if (A and B) is false, then is it A or B that is false? In practice we have in our minds many beliefs, some are held more strongly than others. When an error is found the less strongly held beliefs are considered for modification or deletion first; only if no reasonable change in these is found to fix the error do we look deeper.

A weak form of epistemological solipsism states that the agent has no proof of anything beyond the senses. This can be raw observation, at the level of "I see red", "I am not aware of a proof". A stronger form states "No proof exists", this is falsifiable in as far as anything is. In order to falsify it, a proof must be provided.

Falsificationism indicates that if the mind of the agent produces a self contradiction on its own terms, then (by definition) some error is being made. However, the error can only be located in the agent's mind as a whole. To demonstrate that one aspect (or axiom) of that mind is incorrect requires the assumption that another is correct. If the thesis is that "all entities are aspects of the mind of the agent", then to refute this it is typically required to assume the truth of an axiom that contains the effect of "there do exist things outside the mind of the agent".

According to one argument , no experiment (by a given solipsist A) can be designed to disprove solipsism (to the satisfaction of that solipsist A). However, solipsism can still be refuted by showing it to be internally inconsistent.

The method of the typical scientist is materialist: assuming 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. In common terms, a person may perform psychological test on themselves, without any assumption of an external world. The solipsistic scientist performs experiments to determine the relation between observations, without any presumption that these observations come from a source outside the mind of the solipsist. However, this account needs to be extended to include the co-operative and communitarian nature of science.

Models involving an external world may be used, but will always be purely abstract: used for their ability to predict, but being given no special ontological status. There are, in fact, several distinct versions of Quantum Mechanics, each instrumentally equivalent to the other, but with different ontologies. In a solipsistic science there is no strong desire to determine which is ultimately true — in effect, none of them are, but they all have utility and intuitions to offer. However, non-solipsistic science can explain why anything is ever falsified at all, since a non-mental world does not have to bend to the expectations of science.

Minimalism

Solipsism is a form of logical minimalism. Many people are intuitively unconvinced of the non existence 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 non existence 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.

Pantheism

While solipsism is not generally compatible with traditional views of God, it is somewhat related to Pantheism, the belief that everything is God and part of God. The difference is usually a matter of focus. The pantheist would tend to identify him- or herself as being a part of everything in reality, which is actually all God beneath the surface. For instance, many ancient Indian philosophies advocate the notion that all matter (and thus humans) is subtly interconnected with not only one's immediate surroundings, but with everything in the universe and claim that all that one can perceive is a kind of vision, Samsara. The solipsist, however, would be more likely to put him- or herself in the center, as the only item of reality, with all other beings in reality illusions. It could be said to be another naming dispute; "The Universe" / "God" for the pantheist is "My Unconscious Mind" / "Me" for the solipsist.

Eastern philosophies

Thoughts somewhat similar to solipsism are present in much of eastern philosophy. Taoism and several interpretations of Buddhism, especially Zen, teach that drawing a distinction between self and universe is nonsensical and arbitrary, and merely an artifact of language rather than an inherent truth.

Zen

Hinduism

Advaita Vedanta

Advaita is one of the six best known Hindu philosophical systems, and literally means "non duality." Its first great consolidator was Adi Shankaracharya (788-820), who continued the line of thought of some of the Upanishadic teachers, and that of his teacher's teacher Gaudapada. By analysing the three states of experience—–waking, dreaming, and deep sleep—–he established the singular reality of Brahman, in which the soul and Brahman are one and the same. Ishvara is the manifestation of Brahman to human minds under the influence of an illusionary power called Avidya.

In the Hindu model of reality, brahman, the God-Head, plays a game of hide and seek with himself. In this game, called Lila, he plays the individual people, the birds, the rocks, and forests, all separately and together, while completely forgetting that he is playing a game. Each Kalpa, he ceases the game, wakes up, applauds himself, and resumes it. So one of the main points in "Waking up" and being enlightened, is knowing one is simply playing a game, currently acting as a human being, having an illusion of being locked within a bag of skin and separated from the whole of the cosmos.

"He who sees everything as nothing but the Self, and the Self in everything he 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?" Isha Upanishad; sloka 6, 7

The philosophy of Vedanta which says "Aham Brahmasmi", roughly translated as "I am the Absolute Truth", indicates solipsism in one of its primitive senses. The "real" world is but an illusion in the mind of the observer. When the solipsist understands the "maya" or illusion of world, then he escapes the mundane and reaches the state of everlasting bliss, realizing he, the Self, is the whole universe. thus making himself God. (and everybody else)

Yoga

Yogic practices are sometimes seen to align closely aligned with the Sankhya philosophy, which is an Eastern dualistic system (somewhat distinct from Western dualism) postulating only the existence of mind, and of matter. However, one sometimes sees it explained that, while matter exists for us in the world of Maya (illusion), it is ultimately a product of mind (viz, of Brahman), and is encompassed thereby.

Buddhism

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 of reality that is 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.

Some later representatives of one Yogacara subschool (Prajnakaragupta, Ratnakirti) were proponents of extreme illusionism and solipsism (as well as of solipsism of this moment). The best example of such extreme ideas was the treatise of Ratnakirti (XI century) "Refutation of the existence of other minds" (Santanantara dusana).

[It is important to note that all mentioned Yogacara trends are not purely philosophical but religious–philosophical. All Yogacara discourse takes place within the religious and doctrinal dimension of Buddhism. It is also determined by the fundamental Buddhist problem, that is living being and its liberation from the bondage of Samsara.]

Responses

The following are some common critiques and responses about solipsism:

• People die

But the solipsist himself or herself is not dead. If somebody else dies, the supposed being who has supposedly "died" is only a phantom of the solipsist's imagination anyway, and the elimination of that phantom proves nothing. A critic would point out that many (self-proclaimed) solipsists have died in the history of the world, and solipsism hasn't disappeared yet. However, the solipsist would respond that he or she has not died, and therefore his or her solipsism is not yet disproved. He or she never believed in the existence of those other solipsists in the first place.

• Applicability of the past

The fact that an individual may find a statement such as "I think, therefore I am" applicable to them, yet not originating in their mind indicates that others have had a comparable degree of insight into their own mental processes, and that these are similar enough to the subject's. Further, existence in complete unity with reality means that learning is impossible -- one would have to have awareness of all things. The metaphysical solipsist would respond that, much like other people are products of his own mind, so, too, is "the past" and its attendant information. Thus, "I think, therefore I am" would indeed have originated in their mind.

• Life is imperfect

Why would a solipsist create things such as pain and loss for himself or herself? More generally, it might be asked "If the world is completely in my head, how come I don't live the most fantastic life imaginable?" One response would be to simply plead ignorance and note that there may be some reason which was forgotten on purpose. Another response is that categories such as 'pain' are perceptions assumed with all of the other socio-cultural human values that the solipsist has created for himself — a package deal, so to speak. More creatively, perhaps this is all out of a desire to avoid being bored, or perhaps even that the solipsist is in fact living the most perfect life he or she could imagine. This issue is somewhat related to theodicy, the "problem of evil", except that the solipsist himself is the all-powerful God who has somehow allowed imperfection into his world. A solipsist may also counter that since he never made himself he never had a choice in the way his mind operates and appears to have only limited control over how his experiences evolve. He could also conclude that the world of his own mind's creation is the exact total of all his desires, conscious and otherwise and that each moment is always perfect in the sense that it would not be other than as his own mind in total had made.

The imperfection of life can also be explained through the beliefs of the pseudo-philosophy lachrymology, i.e. that only through pain, both physical and emotional, can one move to a higher state of existence. Thus, it could be theorized that the imperfect present for a solipsist is the direct result of his subconscious compulsion to experience perfection.

The claim that the solipsist's mind is the only thing with certain existence for him (epistemological solipsism) does not inherently address the question of control over the content of that mind. Outside solipsism, a person may know that a phobia is all in the mind but be completely unable to prevent it ruining their life. (Conversely, it is not illogical for a powerful being—a god, for example—to have complete control over the universe, despite it being external to said powerful being.) Solipsism asserts that the mind of the agent is the only thing with assured existence; it need not assert any specific structure to that mind—any more or less than materialism—in and of itself, and requires a specific cosmology. However, any convincing philosophy needs to cohere with what is observed, and metaphysical solipsism needs to credit certain mental contents with the same stubborn indifference to human wishes that material objects display in other philosophies.

In a psychological, rather than philosophical, mode, the delusion that the agent is in complete control of the universe and chooses to have bad things happen is equally compatible with a solipsistic as with a materialistic mindset.

• Other people's skills

If the solipsist created a famous poet in his mind, why doesn't the solipsist have the capacity to imitate their skill? If the solipsist created the poet's poems for them, why can't the solipsist create equally talented poems for themselves?

Answer, if he created the poet, he created the poem. But you can argue that a solipsist does not have the same skills personally as a professional guitarist does. In theory, he should be able to write equally as talented music because he created it, but that is where the problem arises, because the solipsist is not good at guitar.

• Solipsism undercuts morality

If solipsism is true, then practically all standards for moral behavior would seem to be meaningless, according to this argument. There is no God, so that basis for morality is gone, but even secular humanism becomes meaningless since there are no such things as other humans. Everything and everyone else is just a figment of imagination, so there's no particular reason not to make these figments disappear by, say, mass annihilation. The problem with this argument is that it falls prey to the Appeal to Consequences Fallacy; if solipsism is true, then it doesn't matter that it has unfortunate implications. This can possibly be countered by people who believe that (a non-solipsist) morality is an inherent part of the universe that can be proved to exist.

A solipsist may also understand that everything being a part of himself would also mean that harming anything would be harming himself with associated negative consequences such as pain (although the solipsist must be harming himself already, since "life is imperfect"). Or an exponent of a weak form of solipsism might say that harming others is imprudent because the solipsist can only be uncertain of their real existence rather than certain of their non-existence. Another expression of this point is in noting the strong feelings that a human can have for a non-existent character in a movie, or for a car or boat which is admitted to be completely non sentient. There is no logical or psychological reason to prevent a solipsist caring for observed people, even if the solipsist is completely convinced of their non-existence.

• The practical solipsist needs a language to formulate his or her thoughts about solipsism

Language is an essential tool to communicate with other minds. Why does a solipsist universe need a language? Indeed, one might even say, solipsism is necessarily incoherent, a self-refuting idea, for to make an appeal to logical rules or empirical evidence the solipsist would implicitly have to affirm the very thing in which he or she purportedly refuses to believe: the 'reality' of intersubjectively valid criteria, and/or of a public, extra-mental world. A possible response would be that to keep from becoming bored, perhaps the solipsist imagines "other" minds, which would actually be only elements of his own mind. He or she has chosen to forget control of these minds for the time being, and the elaborate languages required for interaction with these more isolated segments of his mind are merely part of the creation of "reality." As for the rules of logic, they are probably merely an artifact of the peculiar psychology of the solipsist and only appear to exist in the "real" world. (However, to argue this way is to admit that solipsism needs to be buttressed with additional, ad-hoc hypotheses).

Greg Egan addressed this issue in his story "Dust" and the subsequent novel based on the story Permutation City by demonstrating that the solipsist can choose to develop his own self-consistent logical system apart from "reality". A more telling question might be, why does the solipsist need to invent so many and such a variety of languages? There is of course E-prime which strives to speak from the personal point of view and seems ideally suited for solipsism.

One famous argument along these lines is the private language argument of Wittgenstein. In brief, this states that since language is for communication, and communication requires two participants, the existence of language in the mind of the thinker means the existence of another mind to communicate with. There is a direct fallacy in this: either, language is for communication between two agents, in which case it is still to be proved that what is in the head of the agent is a language, or what is in the head of the agent is language, in which case it is yet to be proved that language is for communication between two minds. To complicate the situation, the language in the mind of the agent may be for communication between the agent at this time, and the agent at a future time. However, this is no objection to the original argument, which explicitly mentions a kind of "diary" and therefore communication across time.

• Solipsism amounts to realism

An objection, raised by David Deutsch, among others, is that since the solipsist has no control over the "universe" he is creating for himself, there must be some unconscious part of his mind creating it. If the solipsist makes his unconscious mind the object of scientific study (e.g., by conducting experiments), he will find that it behaves with the same complexity as the universe offered by realism; therefore, the distinction between realism and solipsism collapses. What realism calls "the universe", solipsism calls "one's unconscious mind." But these are just different names for the same thing. Both are massively complex processes other than the solipsist's conscious mind, and the cause of all the solipsist's experiences — possibly merely a labeling distinction. Application of Occam's Razor might then suggest that postulating the existence of 'reality' may be a simpler solution than a massive unconscious mind; alternatively the smaller number of entities required to exist for solipsism suggests solipsism is the better choice. In practice, Occam's Razor suffers from a problem in the definition of simplicity. The solipsist would claim that the apparent independence of real world events just shows how good his unconscious mind is at maintaining the illusion. The realist's world may be every bit as complex as the solipsist's unconscious, but when the solipsist dies, the entire universe will cease to exist. (See also, Le Guin, Ursula K. The Lathe of Heaven)

• Philosophical poverty

Some philosophers hold the viewpoint that solipsism is entirely empty and without content. Like a 'faith' argument, it seems sterile, i.e., allows no further argument, nor can it be falsified. The world remains absolutely the same — so where could a solipsist go from there? Viewed in this way, solipsism seems only to have found a facile way to avoid the more difficult task of a critical analysis of what is 'real' and what isn't, and what 'reality' means. Some might say Solipsism is not impoverished because it helps philosophers operate from a principle of doubt because their difficult task can only determine the probability of what is real and what isn't. The solipsist would hold that further argument is meaningless and there are limits to what can be known about 'reality.'

• Workability

Another argument against solipsism is that it has no goal and no way to be applied. The question used in such an argument is, can it be applied? Does it lead to a better or a happier life, in the viewpoint of the solipsist, or anyone else? In other words, if the solipsist believes that nothing is real and there are no goals, what can he spend his time doing and why not just die?

Culture

In Greg Egan's book Permutation City, Egan explores the meaning of solipsism through the concept of the "Solipsist Nation" that is developed by a "Copy" (a self-aware computer simulated human). Since every "Copy" is aware that they are a simulation in a virtual reality, the philosophical ideas from this sub-plot present an unusual and fascinating twist on the concept.

In Mark Twain's "The Mysterious Stranger," the character Satan makes the following statement of solipsism at the end of the novella, "In a little while you will be alone in shoreless space, to wander its limitless solitudes without friend or comrade forever--for you will remain a thought, the only existent thought, and by your nature inextinguishable, indestructible. But I, your poor servant, have revealed you to yourself and set you free. Dream other dreams, and better!...You perceive, now, that these things are all impossible except in a dream. You perceive that they are pure and puerile insanities, the silly creations of an imagination that is not conscious of its freaks - in a word, that they are a dream, and you the maker of it. The dream-marks are all present; you should have recognized them earlier. It is true, that which I have revealed to you; there is no God, no universe, no human race, no earthly life, no heaven, no hell. It is all a dream - a grotesque and foolish dream. Nothing exists but you. And you are but a thought - a vagrant thought, a useless thought, a homeless thought, wandering forlorn among the empty eternities!"

Author Robert A. Heinlein often toyed with themes of a solipsistic "multiverse" in various stories and novels. A good example is his short story "All You Zombies".

In Douglas Adams' The Hitchhiker's Guide to the Galaxy books, the man who rules the universe is a hermit who practices solipsism, to the extent that he is unaware that he rules the universe or even, in fact, that the universe exists.

George Orwell's dystopian novel 1984 features a climactic metaphysical debate: the central character, Winston, argues against "the belief that nothing exists outside your own mind," or the "fallacy" of solipsism; O'Brien, his inquisitor, explains that "collective solipsism" would be a better name for the totalitarian scheme, but would also be nearly the opposite of solipsism in theory. Winston ultimately loses this debate, and learns that truth is defined by power and not the human mind. (Chapter 3, Section III)

In the Nine Inch Nails song "Right Where It Belongs" from the album With Teeth, the lead singer Trent Reznor sings on the matter of solipsism.

In Iain M. Banks' sci-fi novel Against a Dark Background, the female protagonist Sharrow meets The Solipsists, a gang of pirate mercenaries on a hovercraft, who hold very unusual philosophical beliefs.

In The Chronicles of Amber, the fantasy series by Roger Zelazny, the protagonist, Corwin, travels through different worlds simply by imagining them in detail and willing himself there. He comments specifically on the solipsistic nature of this 'travel', speculating that he creates these worlds rather than 'finding' them, but he rejects the idea of solipsism in general.

In John Gardner's novel Grendel, Grendel battles a bull and, since the bull cannot change his way of attacking, and because Grendel discovers he can avoid the blows, Grendel concludes that he alone exists.

Solipsist sentiment can be seen to a limited extent in the premise behind The Matrix movies.

The Planescape Dungeons & Dragons setting features a faction called the Sign of One that represents a generally solipsist perspective.

The Fiona Apple song "Paper Bag" hints at solipsism in the lines "He said 'It's all in your head,' and I said, 'So's everything' But he didn't get it." http://www.lyricsdomain.com/6/fiona_apple/paper_bag.html

In the popular anime series, Deathnote, a song called "Low of Solipsism" is used when the main character is having episodes of extreme thought and appears to have formulated a plan to solve his problems, perhaps alluding that his reasoning is only perfect in his head.

In Stephen King's novel, It, character Patrick Hockstetter suffers from Solipsism Syndrome.

Notes

References

• Carus, Titus Lucretius, (Lucretius), (c. 50 BC), De Rerum Natura (On the Nature of Things), Eprint
• Khashaba, D.R. (2002), "Subjectivism and Solipsism", Eprint.
• Peake, Anthony Is There Life After Death? (2006), Anthony Peake, Arcturus–Foulsham (Europe), & Chartwell Books, Inc. (USA). This book presents an intriguing and scientifically-based updating of solipsism involving the latest findings in quantum physics, neurology and consciousness studies.http://www.anthonypeake.com.
• Popper, K.R., and Eccles, J.C. (1977), The Self and Its Brain, Springer-Verlag, Heidelberg, Germany.
• Russell, Bertrand (1912), The Problems of Philosophy, 1st published 1912. Reprinted, Galaxy Book, Oxford University Press, New York, NY, 1959. Reprinted, Prometheus Books, Buffalo, NY, 1988.
• Russell, Bertrand, (1921) The Analysis of Mind, Allen and Unwin, London, UK. Reprinted, Routledge, London, UK, 1995.
• Ryal, Tomas, (1985) Solitude, Taylor and Edwards, London, UK. 1st published 1934 in German, as Der Einsamkeit.
• von Schubert Soldern, Richard (1982), Über Transcendenz des Objects und Subjects, Leipzig.
• Thornton, Stephen P. (2006), "Solipsism and the Problem of Other Minds", Internet Encyclopedia of Philosophy, James Fieser and Bradley Dowden (eds.), Eprint.
• Wittgenstein, Ludwig, Philosophical Investigations, Blackwell, 1974.
• Wood, Ledger (1962), "Solipsism", p. 295 in Runes (ed.), Dictionary of Philosophy, Littlefield, Adams, and Company, Totowa, NJ.

Reference works

• Runes, Dagobert D. (ed., 1962), Dictionary of Philosophy, Littlefield, Adams, and Company, Totowa, NJ.
• Webster's New International Dictionary of the English Language, Second Edition, Unabridged (1950), W.A. Neilson, T.A. Knott, P.W. Carhart (eds.), G. & C. Merriam Company, Springfield, MA. Cited as MWU.
• Webster's Ninth New Collegiate Dictionary (1983), Frederick C. Mish (ed.), Merriam–Webster Inc., Springfield, MA. Cited as MWC.

See also

Dramatis personae

• George Berkeley
• René Descartes
• Henri Barbusse's "Hell"

Related topics

• Cartesian skepticism
• Consensus reality
• Dream argument
• Empiricism
• Falsifiability
• Heinlein's pantheistic solipsism
• Idealism
• Immaterialism
• Metaphysical solipsism
• Methodological solipsism
• Objective idealism
• Panpsychism
• Phenomenalism
• Philosophical realism
• Primary/secondary quality distinction -Kant's response to solipsism
• Problem of other minds
• Henry Rollins's Solipsist
• Solipsism syndrome
• Subjective idealism
• Alfred Binet-The mind and the brain

External links

• Solipsism and the Problem of Other Minds
• Solipsism experienced as a dissociative symptom of mental illness
• The Solipsist Web Ring