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Solipsism (i//; 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. As such it is the only epistemological position that, by its own postulate, is both irrefutable and yet indefensible in the same manner.
There are varying degrees of solipsism that parallel the varying degrees of serious skepticism.
Metaphysical solipsism is the "strongest" 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 reality, including the external world and other persons, are representations of that self, and have no independent existence.citation needed
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.
Epistemological solipsists claim that realism requires the question: assuming that there is a universe that is independent of the agent's mind, the agent can only ever know of this universe through its senses, how is the existence of the independent universe to be scientifically studied? If a person sets up a camera to photograph the moon when they are not looking at it, then at best they determine that there is an image of the moon in the camera when they eventually look at it. Logically, this does not assure that the moon itself (or even the camera) existed at the time the photograph is supposed to have been taken. To establish that it is an image of an independent moon requires many other assumptions that amount to begging the question. (Mind over Matter)citation needed
Methodological solipsism may be a sort of weak agnostic (meaning "missing knowledge") solipsism. It is a consequence of strict epistemological requirements for "Knowledge" (e.g. the requirement that knowledge must be certain). They still entertain the points that any induction is fallible and that we may be brains in vats. However there are those who 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 brain. There are thoughts, but that's all that's known for certain.
Importantly, they do not intend to conclude that the stronger forms of solipsism are actually true. Methodological solipsists 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 (Wood, 295). 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).citation needed
- See also: Solipsism: Relation to other ideas (below)
Denial of materialistic existence, in itself, does not constitute solipsism.
Possibly the most controversial feature of the 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"1 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 (see the brain in a vat).
- The experience of a given person is necessarily private to that person.
Solipsism is not a single concept but instead refers to several worldviews whose common element is some form of denial of the existence of a universe independent from the mind of the agent.citation needed
- 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).
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 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".citation needed
George Berkeley's arguments against materialism in favor of idealism provide the solipsist with a number of arguments not found in Descartes. While the latter 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.3
Solipsism is often introduced in the context of relating it to pathological psychological conditions.citation needed Austrian neurologist Sigmund Freud stated that other minds are not known, but only inferred to exist, he stated "consciousness makes each of us aware only of his own states of mind, that other people, too, possess a consciousness is an inference which we draw by analogy from their observable utterances and actions, in order to make this behavior of theirs intelligible to us. (It would no doubt be psychologically more correct to put it in this way: that without any special reflection we attribute to everyone else our own constitution and therefore our consciousness as well, and that this identification is a sine qua non of understanding)."4
Solipsism syndrome is a dissociative mental state. 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.citation needed
Developmental psychologists commonly believe that infants are solipsist,5 and that eventually children infer that others have experiences much like theirs and reject solipsism (see Infant metaphysics).
To discuss consequences clearly, an alternative is required: solipsism as opposed to what? Solipsism is opposed to all forms of realism and many forms of idealism (insofar as they claim that there is something outside the idealist's mind, which is itself another mind, or mental in nature). Realism in a minimal sense, that there is an external universe is most likely not observationally distinct from solipsism. The objections to solipsism therefore have a theoretical rather than an empirical thrust.
Solipsists may view their own pro-social behaviors as having a more solid foundation than the incoherent pro-sociality of other philosophies. Indeed, they may be more pro-social because they view other individuals as actually being a part of themselves. Furthermore, the joy and suffering arising from empathy is just as real as the joy and suffering arising from physical sensation. They view their own existence as human beings to be just as speculative as the existence of anyone else as a human being. Epistemological solipsists may argue that these philosophical distinctions are irrelevant since the professed pro-social knowledge of others is an illusion.
Would the last person left alive be a solipsist? Not necessarily. The last surviving person would of course have to confront and accept that his or her consciousness is the only local human consciousness in existence (subject to verification that all other humans have not survived), whereas a solipsist believes that his or her consciousness is the only one in existence regardless of who else, if anyone, is living. If the last surviving person is a solipsist, he or she will believe that even when others were alive, there never had been another thought, experience or emotion other than his or her own.citation needed
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. Materialism6 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 cannot collectively sense is not in any way 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 around 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.7 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).689 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.
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 all 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).1011 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.1213 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".
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 to the relationship between human will and human body.
The idealist philosopher George Berkeley argued that physical objects do not exist independently of the 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. 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 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 observations of alleged other people and rely upon the immediate certainty of one's own perceptions.14
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.
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.
Solipsism is not a falsifiable hypothesis as described by Karl Popper or Imre Lakatos: there does not seem to be an imaginable disproof. Not even the complete death of the solipsist could falsify his belief in solipsism because he could not analyze that observation.
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 of the mind would be locked.
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 (David Deutsch uses this fact to counter-argue below). This investigation 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.
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.
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. They claim that the perception of absolutely independent beings and things is an illusion that leads to confusion and dissatisfaction—Samsara. The solipsist, however, would be more likely to put one's self (or merely their own mind) in the center, as the only item of reality, with all other beings (and perhaps even their own body) in reality illusions.
Some solipsistswho? believe that some tenets of eastern philosophies are similar to solipsism. Taoismcitation needed and several interpretations of Buddhism, especially Zen, teach that the distinction between self and universe is arbitrary, merely a habit of perception and an artifact of language. This view identifies the unity of self and universe as the ultimate reality. Zen holds that each individual has 'Buddha Mind': an all-pervading awareness that fills their entire existence, including the 'external' world. This need not imply that one's mind is all that exists, as with solipsism, but rather that the distinction between "I am" and "it is" is ultimately unnecessary, and a burden that, paradoxically, gives rise to an illusory sense of permanence and independence—that "separate" self which suffers and dies. In this sense, Zen reflects Meister Eckhart's "The eye with which I see God is the same with which God sees me. My eye and God's eye is one eye, and one sight, and one knowledge, and one love." Zen works across both divisions of inside "me" and outside "me", with meditation practice unravelling the very notion of binary oppositions, which ultimately are seen as the source of any "problem" of solipsism.citation needed
Earliest reference to Solipsism in Hindu philosophy is found in the Brihadaranyaka Upanishad, dated to early 1st millennium BCE.15 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.16 After the development of distinct schools of Indian philosophy, Advaita Vedanta and Samkhya schools are thought to have originated concepts similar to solipsism.
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?— Ishopanishad: sloka 6, 7
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 is 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.17
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.citation needed
Samkhya philosophy, which is sometimes seen as the basis of Yogic thought,18 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.19 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 asserts that external reality is an illusion, and sometimes this position is misunderstood as Solipsism. Buddhist doctrine, though, holds that both 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 is a process known as Pratītyasamutpāda, or "co-dependent origination."
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".20 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 challenged as illusion the idea that one can experience an 'objective' reality independent of individual perceiving minds.
According to the Sutra Prasangika view, external objects do exist, just not inherently: "Just as objects of mind do not exist [inherently], mind also does not exist [inherently]".21 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.
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 (11th century) "Refutation of the existence of other minds" (Santanantara dusana).
Note: 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 the living being and its liberation from the bondage of Samsara.
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There are a number of critiques of, and responses to, solipsism.
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The person dies, but the solipsist themself 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.
For the solipsist, death can only ever be "the death of the other". He/she never believed in the existence of those other solipsists in the first place. Note however that a sentence reflecting a supposed understanding of the actions of others, such as one that contains a statement like "he or she never believed..." or "those others" is already stepping outside of the solipsist's subjective viewpoint, and so misleading when used to illustrate a solipsistic view of death. For the solipsist, death is like the end of a dream. The dream itself, the setting, and any characters within that dream would not be thought to continue after waking. Ergo, if waking life is like a dream, why should the setting or characters perceived within it continue on after the death of the subject from that dream either?
Because they were illusions to begin with. A character can be imagined but when they are not being imagined it's like they died—until they are imagined again. In the same sense an illusion can die and live after death in the same way that an image of imagination can be re-imagined.
Some might argue that to exist in complete unity with reality would mean to be unable to learn—one would have to have awareness of all things. The solipsist would probably not appeal to such knowledge being contained in their subconscious, since the existence of a world of information outside consciousness is exactly what the solipsist disavows. Instead the solipsist might suggest that the world that exists is always restricted to his/her field of vision—the way no world exists behind the walls of a stage's set, video game environment, or in a dream.
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. 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.
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. 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. 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. A third response is to say that, like a dream, the solipsist's subconscious mind creates a world which the solipsist's conscious mind might not have chosen but has no control over changing.
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.14
The imperfection of life can also be explained through the belief 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.
A variant of this problem questions the existence of other people's skills the solipsist lacks. If the solipsist created a famous poet in his mind, why doesn't the solipsist have the capacity to imitate their skill? Similar to pain, there is some reason that the solipsist has denied himself this ability, but it may not be knowable or explainable.
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. 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.
If the world is in the mind of a solipsist, then why doesn't a perfect world exist? For the same reason that people are able to have nightmares even though they also come from the mind.
If solipsism is true, then practically all standards for moral behavior would seem to be meaningless. According to this argument there is no "creator", no deity, so that an external, "objective" basis for morality is gone. Other forms of morality that do not rely on the existence of an infallible deity, such as secular humanism, also become meaningless because 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; whether or not solipsism is true does not depend on its implications.
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 need to communicate with other minds when, to the solipsist, those "other minds" don't exist? So why does a solipsist universe need a language? Indeed, some 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.22
Solipsism does not deny the possibility of a systemically orderly world, it denies the existence of other consciousness apart from the solipsist. The concept of the world having being created by a solipsist is not inherently against the concept of said world having rules. Appealing to empirical knowledge could be interpreted as the creator appealing to rules it itself created, why the solipsist would do this in turn goes to further unrelated topics mentioned below. Another variant of solipsism is indeed against this, considering said variants could state that what is not observed does not exist. Leading to further possible answers both inclusive and exclusive of empiricism as its logical basis, possibly ranging into a different logical system or, due to the characteristics of solipsism itself, to an original logic. As for the necessity to appeal to an intersubjective reality, a solipsist could say that there can be no intersubjectivity because there is not subjectivity at all, it could be said that no one is truly real, therefore they have no subjectivity whatsoever. Instead appealing to others could be interpreted as the solipsist fulfilling its own rules it itself created (this leads to interesting questions as to why the solipsist's rules would require it to reach agreements in a code the solipsist made with agents the solipsist created for the personal gratification of the solipsist).
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.
This argument does not refute solipsism as it might even appear that one using it doesn't really understand the private language argument. Wittgenstein's argument says there's no such thing as a language that is both meaningful and understandable by one person but which is impossible for any other person to understand. If, for example, the solipsist's language is English then that alone makes the Private Language Argument useless against solipsism because English is a language that CAN theoretically be understood by multiple people. So for solipsism if we assume there's only one human in the universe, no languages are private unless no theoretical second person can comprehend it. You don't actually need a second person but just theory.
A solipsist might also argue that there never was anyone to begin with, so all the details of the perceived world including language are completely irrelevant (as say, English, could not ever be understood by anyone as there was never truly someone to do so. Instead the other alleged recipients of the language could just be means the solipsist itself created to reach a language of its own creation, the same would apply with all philosophy and physical laws, which are imperfect at that point). As mentioned previously the solipsist can state that everything including physics, evolution and language are mere constructs made for one reason or another while in a state of higher intelligence. Alternate explications could lead to a different conclusions: Either the laws of physics are constantly created by the solipsist to permit its own existence; or everything ranging from thought itself to physics were created by the solipsist for a particular instance. In which case a question is opened, can a solipsist have possibly existed without physics, or physics are coverups for some constant primal quality of the solipsist's own existence? This leaves another question in turn, can the solipsist claim that his current consciousness is limited in comparison with its full potential, in which case, why would the available intellectual potential be limited to begin with? Whatever triggered this arbitrary decision could be the creative property of the solipsist itself. That would reduce the solipsist to an impersonal force that by either pure chance or something else managed to create the laws that could in turn accidentally developed the life that gives said force the ability to have thoughts occupying the consciousness. By said logic at some point the solipsist may have either evolved into a thinking being, or the solipsist created the laws that permit the solipsist's primal attributes to be explained to begin with.
Some philosophers, notably Bertrand Russell, 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. The solipsist might hold in response that further argument is meaningless. He might explain that, granting only the most basic laws of thought, he has identified the real limits of what can be truly known about 'reality': cogito ergo sum.
An objection, raised by David Deutsch23 (among others), is that since the solipsist has no control over the "universe" she is creating for herself, there must be some part of her mind, of which she is not conscious, that is doing the creating. If the solipsist makes her unconscious mind the object of scientific study (e.g. by conducting experiments), she will find that it behaves with the same complexity as the universe described by a realist. Thus what realism calls "the universe", solipsism calls "one's unconscious mind." Understood this way, the distinction between realism and solipsism collapses and amounts to different ways of describing the same thing: a massively complex process that causes all of the solipsist's experiences, but is not identical to the solipsist's conscious mind. However despite this the solipsist could still maintain that, unlike Deutsch's views, that which causes her experiences are still a part of her mind.
Presumably having made the case that the solipsist scientist is actually a realist scientist, Deutsch next argues in favor of the more common understanding of reality. He applies Occam's Razor, and suggests that it prefers the standard external 'reality' over something like a brain in a vat. This is because the standard 'reality' fits all the data available to the scientist, rendering superfluous the other more complicated possibilities.
If seeking to avoid rejecting the laws of thought, the solipsist may easily appeal to the Problem of Induction. With this he could nullify the use of Occam's Razor and even Deutsch's first premises on the solipsists mind, since they are arguments made using inductive reasoning. The Realist Society of Canada has a religious holiday dedicated to the knowledge of self existence called IKIE (pronounced \ˈīk\) celebrated on the third Friday in March each year.24
Some forms of Solipsism can co exist with the belief in God, unrelated to the belief that the world is in the mind of the solipsist and that he is the sole creator of the world. The Solipsist who believes in God is aware of the creator and has no relation to the belief that he himself is God. He believes that multiple consciousness is part of the realm of impossibility, perceiving God's creations can only be perceived by one. This also results in the belief that God is unconscious as well and that consciousness is not needed to perform actions such as creating life. Consciousness only provides the ability of being aware of the actions that are performed.citation needed
- Thornton, Stephen P. (24 October 2004). "Solipsism and the Problem of Other Minds". Internet Encyclopedia of Philosophy.
- Edward Craig; Routledge (Firm) (1998). Routledge Encyclopedia of Philosophy: Genealogy to Iqbal. Taylor & Francis US. pp. 146–. ISBN 978-0-415-18709-1. Retrieved 16 October 2010.
- Jones, N.; Berkeley, G. (2009). Starting with Berkeley. Starting with. Continuum. p. 105. ISBN 978-1-84706-186-7. LCCN 2008053026.
- Freud, Sigmund Gay, Peter edit. The Freud Reader 1995 New York WW Norton page 575
- Flanagan, Owen J. (1991). The Science of the Mind. MIT Press. p. 144. ISBN 0-262-56056-9, 9780262560566 Check
|isbn=value (help). Retrieved 2008-10-22.
- "Materialism". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.
- "Idealism". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.
- Loflin, Lewis. "Notes on Neoplatonism and the relation to Christianity and Gnosticism".
- "German Idealism". Internet Encyclopedia of Philosophy. 16 April 2001.
- DePoe, John M. "A Defense of Dualism". New Dualism Archive.
- "Dualism". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.
- Calef, Scott (9 June 2005). "Dualism and Mind". Internet Encyclopedia of Philosophy.
- Thornton, Stephen P. (24 October 2004). "Solipsism and the Problem of Other Minds". Internet Encyclopedia of Philosophy.
- Khashaba, D.R. (28 July 2002). "Subjectivism and Solipsism". Philosophy Pathways (37).
- King, Richard; Ācārya, Gauḍapāda (1995), Early Advaita Vedānta and Buddhism: the Mahāyāna context of the Gauḍapādīya-kārikā, SUNY Press, p. 52, ISBN 978-0-7914-2513-8
- Krishnananda, (Swami). The Brihadaranyaka Upanishad. Divine Life Society, Rishikesh. P. 248.
- O'Flaherty, Wendy Doniger. Dreams, Illusion, and Other Realities. Universoty of Chicago, 1984. pp. 120–1. ISBN 0-226-61855-2.
- Radhankrishnan, Indian Philosophy, London, George Allen & Unwin Ltd., 1971 edition, Volume II, p. 342.
- Isaac, J. R.; Dangwal, Ritu; Chakraborty, C. Proceedings. International conference on cognitive systmes (1997). Allied Publishers Ltd. pp. 341–2. ISBN 81-7023-746-7.
- Rohitassa Sutta: To Rohitassa
- Chandrakirti, Guide to the Middle Way 6:71cd, translation in Ocean of Nectar: Wisdom and Compassion in Mahayana Buddhism, London: Tharpa Publications, p. 253.
- Jacquette, Dale (1994). "Wittgenstein on private language and private mental objects". Wittgenstein Studies (1).
- Deutsch, David. "David Deutsch on Solipsism". The Free Woods.
- "The Realist Society of Canada Religious Holidays" http://www.realistsocietyofcanada.com/realism-holidays
- Carus, Titus Lucretius (c. 50 BC). De Rerum Natura On the Nature of Things. ISBN 84-85708-46-6.
- Khashaba, D.R. (28 July 2002). "Subjectivism and Solipsism". Philosophy Pathways (37).
- Peake, Anthony (2006). Is There Life After Death?. Arcturus–Foulsham (Europe), Chartwell Books (USA). ISBN 0-7858-2162-7. This book presents an intriguing and scientifically based updating of solipsism involving the latest findings in quantum physics, neurology and consciousness studies.
- Popper, K.R.; Eccles, J.C. (1977). The Self and Its Brain. Heidelberg, Germany: Springer-Verlag. ISBN 0-387-08307-3.
- Russell, Bertrand (1988) . The Problems of Philosophy. Buffalo, NY: Prometheus Books. ISBN 0-7546-1210-4.
- Russell, Bertrand (1995) . The Analysis of Mind. London, UK: Routledge. ISBN 0-415-09097-0.
- von Schubert Soldern, Richard (1982). Über Transcendenz des Objects und Subjects. Leipzig.
- Thornton, Stephen P. (24 October 2004). "Solipsism and the Problem of Other Minds". In Fieser, James; Dowden, Bradley. Internet Encyclopedia of Philosophy.
- Wittgenstein, Ludwig (1974). Philosophical Investigations. Blackwell. ISBN 0-631-19064-3.
- Wood, Ledger (1962). "Solipsism". In Runes. Dictionary of Philosophy. Totowa, NJ: Littlefield, Adams, and Company. p. 295.
- Runes, Dagobert D., ed. (1962). Dictionary of Philosophy. Totowa, NJ: Littlefield, Adams, and Company.
- Neilson, W.A.; Knott, T.A.; Carhart, P.W., eds. (1950). Webster's New International Dictionary of the English Language (Second, Unabridged ed.). Springfield, MA: G. & C. Merriam Company.
- Mish, Frederick C., ed. (1983). Webster's Ninth New Collegiate Dictionary. Springfield, MA: Merriam–Webster.
- Solipsism and the Problem of Other Minds
- Solipsism experienced as a dissociative symptom of mental illness