Reality is the sum or aggregate of all that is real or existent within the universe, as opposed to that which is only imaginary, nonexistent or nonactual. The term is also used to refer to the ontological status of things, indicating their existence.[1] In physical terms, reality is the totality of a system, known and unknown.[2]
Philosophical questions about the nature of reality or existence or being are considered under the
as sources and methods to determine or investigate reality.
World views
World views and theories
Further information:
World view
A common colloquial usage would have reality mean "perceptions, beliefs, and attitudes toward reality", as in "My reality is not your reality." This is often used just as a colloquialism indicating that the parties to a conversation agree, or should agree, not to quibble over deeply different conceptions of what is real. For example, in a religious discussion between friends, one might say (attempting humor), "You might disagree, but in my reality, everyone goes to heaven."
Reality can be defined in a way that links it to worldviews or parts of them (conceptual frameworks): Reality is the totality of all things, structures (actual and conceptual), events (past and present) and phenomena, whether observable or not. It is what a world view (whether it be based on individual or shared human experience) ultimately attempts to describe or map.
A
normative postulates; or themes, values, emotions, and ethics.[4]
Certain ideas from physics, philosophy, sociology, literary criticism, and other fields shape various theories of reality. One such theory is that there simply and literally is no reality beyond the perceptions or beliefs we each have about reality.[citation needed] Such attitudes are summarized in popular statements, such as "Perception is reality" or "Life is how you perceive reality" or "reality is what you can get away with" (Robert Anton Wilson), and they indicate anti-realism – that is, the view that there is no objective reality, whether acknowledged explicitly or not.
The concept of potentiality, in this context, generally refers to any "possibility" that a thing can be said to have. Aristotle did not consider all possibilities the same, and emphasized the importance of those that become real of their own accord when conditions are right and nothing stops them.[9]
Actuality, in contrast to potentiality, is the motion, change or activity that represents an exercise or fulfillment of a possibility, when a possibility becomes real in the fullest sense.[10]
A belief is a subjective attitude that a proposition is true or a state of affairs is the case. A subjective attitude is a mental state of having some stance, take, or opinion about something.[11] In epistemology, philosophers use the term "belief" to refer to attitudes about the world which can be either true or false.[12] To believe something is to take it to be true; for instance, to believe that snow is white is comparable to accepting the truth of the proposition "snow is white". However, holding a belief does not require active introspection. For example, few individuals carefully consider whether or not the sun will rise tomorrow, simply assuming that it will. Moreover, beliefs need not be occurrent (e.g. a person actively thinking "snow is white"), but can instead be dispositional (e.g. a person who if asked about the color of snow would assert "snow is white").[12]
There are various ways that contemporary
eliminativists about belief who argue that there is no phenomenon in the natural world which corresponds to our folk psychological concept of belief (Paul Churchland) and formal epistemologists who aim to replace our bivalent notion of belief ("either we have a belief or we don't have a belief") with the more permissive, probabilistic notion of credence ("there is an entire spectrum of degrees of belief, not a simple dichotomy between belief and non-belief").[12][13]
Beliefs are the subject of various important philosophical debates. Notable examples include: "What is the rational way to revise one's beliefs when presented with various sorts of evidence?", "Is the content of our beliefs entirely determined by our mental states, or do the relevant facts have any bearing on our beliefs (e.g. if I believe that I'm holding a glass of water, is the non-mental fact that water is H2O part of the content of that belief)?", "How fine-grained or coarse-grained are our beliefs?", and "Must it be possible for a belief to be expressible in language, or are there non-linguistic beliefs?"[12]
There is research investigating specific beliefs, types of beliefs and patterns of beliefs. For example, a study estimated contemporary prevalence and associations with belief in
psychedelics can shift beliefs in some humans in certain ways, such as increasing attribution of consciousness to various entities (including plants and inanimate objects) and towards panpsychism and fatalism.[19][20]
Western philosophy
Philosophy addresses two different aspects of the topic of reality: the nature of reality itself, and the relationship between the mind (as well as language and culture) and reality.
On the one hand,
categories of reality and how they are interrelated. If a philosopher wanted to proffer a positive definition of the concept "reality", it would be done under this heading. As explained above, some philosophers draw a distinction between reality and existence. In fact, many analytic philosophers today tend to avoid the term "real" and "reality" in discussing ontological issues. But for those who would treat "is real" the same way they treat "exists", one of the leading questions of analytic philosophy
has been whether existence (or reality) is a property of objects. It has been widely held by analytic philosophers that it is not a property at all, though this view has lost some ground in recent decades.
On the other hand, particularly in discussions of
Weltanschauung
.
Realism
The view that there is a reality independent of any beliefs, perceptions, etc., is called realism. More specifically, philosophers are given to speaking about "realism about" this and that, such as realism about universals or realism about the external world. Generally, where one can identify any class of object, the existence or essential characteristics of which is said not to depend on perceptions, beliefs, language, or any other human artifact, one can speak of "realism about" that object.
A
correspondence theory of knowledge about what exists claims that "true" knowledge of reality represents accurate correspondence of statements about and images of reality with the actual reality that the statements or images are attempting to represent. For example, the scientific method can verify that a statement is true based on the observable evidence that a thing exists. Many humans can point to the Rocky Mountains and say that this mountain range
exists, and continues to exist even if no one is observing it or making statements about it.
Anti-realism
One can also speak of anti-realism about the same objects.
social issues such as morality are not absolute, but at least partially cultural artifact
.
Being
The nature of
ontological argument for the existence of God. Existence, that something is, has been contrasted with essence
, the question of what something is.
Since existence without essence seems blank, it associated with
nothingness by philosophers such as Hegel. Nihilism represents an extremely negative view of being, the absolute
a positive one.
Explanations for the existence of something rather than nothing
epistemological dualism,[29] the philosophical position that our conscious experience is not of the real world itself but of an internal representation, a miniature virtual-reality
replica of the world.
representative realism. The theory states that, with a subconscious set of mental filters formed from their beliefs and experiences, every individual interprets the same world differently, hence "Truth is in the eye of the beholder". His ideas influenced the work of his friend Robert Anton Wilson
.
Abstract objects and mathematics
The status of abstract entities, particularly numbers, is a topic of discussion in mathematics.
In the
Platonic realism
, which grants them abstract, immaterial existence. Other forms of realism identify mathematics with the concrete physical universe.
Anti-realist stances include
fictionalism
.
Some approaches are selectively realistic about some mathematical objects but not others.
The traditional debate has focused on whether an abstract (immaterial, intelligible) realm of numbers has existed in addition to the physical (sensible, concrete) world. A recent development is the mathematical universe hypothesis, the theory that only a mathematical world exists, with the finite, physical world being an illusion within it.
An extreme form of realism about mathematics is the
mathematical multiverse hypothesis advanced by Max Tegmark. Tegmark's sole postulate is: All structures that exist mathematically also exist physically. That is, in the sense that "in those [worlds] complex enough to contain self-aware substructures [they] will subjectively perceive themselves as existing in a physically 'real' world".[30][31] The hypothesis suggests that worlds corresponding to different sets of initial conditions, physical constants, or altogether different equations should be considered real. The theory can be considered a form of Platonism in that it posits the existence of mathematical entities, but can also be considered a mathematical monism
in that it denies that anything exists except mathematical objects.
The problem of universals is an ancient problem in
relations, such as being male/female, solid/liquid/gas or a certain colour,[32]
that can be predicated of individuals or particulars or that individuals or particulars can be regarded as sharing or participating in. For example, Scott, Pat, and Chris have in common the universal quality of being human or humanity.
The realist school claims that universals are real – they exist and are distinct from the particulars that instantiate them. There are various forms of realism. Two major forms are
Platonic realism is the view that universals are real entities and they exist independent of particulars. Aristotelian realism, on the other hand, is the view that universals are real entities, but their existence is dependent on the particulars that exemplify them.
A traditional realist position in ontology is that time and space have existence apart from the human mind. Idealists deny or doubt the existence of objects independent of the mind. Some anti-realists whose ontological position is that objects outside the mind do exist, nevertheless doubt the independent existence of time and space.
objects are, and temporal measurements are used to quantitatively compare the interval between (or duration of) events
. Although space and time are held to be transcendentally ideal in this sense, they are also empirically real, i.e. not mere illusions.
As well as differing about the reality of time as a whole, metaphysical theories of time can differ in their ascriptions of reality to the past, present and future separately.
Presentism
holds that the past and future are unreal, and only an ever-changing present is real.
The
block universe theory, also known as Eternalism, holds that past, present and future are all real, but the passage of time is an illusion. It is often said to have a scientific basis in relativity
.
The growing block universe theory holds that past and present are real, but the future is not.
worlds, some "nearer" to the actual world and some more remote. Other theorists may use the Possible World framework to express and explore problems without committing to it ontologically.
Possible world theory is related to
many worlds interpretation
of quantum mechanics is a similar idea in science.
The philosophical implications of a physical TOE are frequently debated. For example, if philosophical physicalism is true, a physical TOE will coincide with a philosophical theory of everything.
Other philosophers do not believe its techniques can aim so high. Some scientists think a more mathematical approach than philosophy is needed for a TOE, for instance Stephen Hawking wrote in A Brief History of Time that even if we had a TOE, it would necessarily be a set of equations. He wrote, "What is it that breathes fire into the equations and makes a universe for them to describe?"[34]
Phenomenology
On a much broader and more subjective level,[specify] private experiences, curiosity, inquiry, and the selectivity involved in personal interpretation of events shapes reality as seen by one and only one person[35] and hence is called phenomenological. While this
form of reality might be common to others as well, it could at times also be so unique to oneself as to never be experienced or agreed upon by anyone else. Much of the kind of experience deemed spiritual occurs on this level of reality.
Phenomenology is a
philosophical method developed in the early years of the twentieth century by Edmund Husserl and a circle of followers at the universities of Göttingen and Munich
in Germany. Subsequently, phenomenological themes were taken up by philosophers in France, the United States, and elsewhere, often in contexts far removed from Husserl's work.
The word phenomenology comes from the
phenomena which appear in acts of consciousness, objects of systematic reflection and analysis. Such reflection was to take place from a highly modified "first person" viewpoint, studying phenomena not as they appear to "my" consciousness, but to any consciousness whatsoever. Husserl believed that phenomenology could thus provide a firm basis for all human knowledge, including scientific knowledge, and could establish philosophy as a "rigorous science".[36]
Husserl's conception of phenomenology has also been criticised and developed by his student and assistant
Skeptical hypotheses in philosophy suggest that reality could be very different from what we think it is; or at least that we cannot prove it is not. Examples include:
The "Brain in a vat" hypothesis is cast in scientific terms. It supposes that one might be a disembodied brain kept alive in a vat, and fed false sensory signals. This hypothesis is related to the Matrix hypothesis below.
The "Dream argument" of Descartes and Zhuangzi supposes reality to be indistinguishable from a dream.
Descartes' Evil demon is a being "as clever and deceitful as he is powerful, who has directed his entire effort to misleading me."
The
Last Thursdayism
) suggests that the world was created recently together with records and traces indicating a greater age.
Diminished reality refers to artificially diminished reality, not due to limitations of sensory systems but via artificial filters[38]
. Related hypotheses may also involve simulations with signals that allow the inhabitant species in virtual or simulated reality to perceive the external reality.
Moksha – Liberation or Salvation, i.e. the complete annihilation of all karmic matter (bound with any particular soul).
Physical sciences
Scientific realism
Scientific realism is, at the most general level, the view that the world (the universe) described by science (perhaps ideal science) is the real world, as it is, independent of what we might take it to be. Within philosophy of science, it is often framed as an answer to the question "how is the success of science to be explained?" The debate over what the success of science involves centers primarily on the status of entities that are not directly observable discussed by scientific theories. Generally, those who are scientific realists state that one can make reliable claims about these entities (viz., that they have the same ontological status) as directly observable entities, as opposed to instrumentalism. The most used and studied scientific theories today state more or less the truth.
Realism and locality in physics
Realism in the sense used by physicists does not equate to realism in metaphysics.[41]
The latter is the claim that the world is mind-independent: that even if the results of a measurement do not pre-exist the act of measurement, that does not require that they are the creation of the observer. Furthermore, a mind-independent property does not have to be the value of some physical variable such as position or momentum. A property can be dispositional (or potential), i.e. it can be a tendency: in the way that glass objects tend to break, or are disposed to break, even if they do not actually break. Likewise, the mind-independent properties of quantum systems could consist of a tendency to respond to particular measurements with particular values with ascertainable probability.[42] Such an ontology would be metaphysically realistic, without being realistic in the physicist's sense of "local realism" (which would require that a single value be produced with certainty).
A closely related term is counterfactual definiteness (CFD), used to refer to the claim that one can meaningfully speak of the definiteness of results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured).
interpretations of quantum mechanics violate different parts of local realism and/or counterfactual definiteness
.
The transition from "possible" to "actual" is a major topic of
The founders of quantum mechanics debated the role of the observer, and of them, Wolfgang Pauli and Werner Heisenberg believed that it was the observer that produced collapse. This point of view, which was never fully endorsed by Niels Bohr, was denounced as mystical and anti-scientific by Albert Einstein. Pauli accepted the term, and described quantum mechanics as lucid mysticism.[44]
Heisenberg and Bohr always described quantum mechanics in logical positivist terms. Bohr also took an active interest in the philosophical implications of quantum theories such as his complementarity, for example.[45] He believed quantum theory offers a complete description of nature, albeit one that is simply ill-suited for everyday experiences – which are better described by classical mechanics and probability. Bohr never specified a demarcation line above which objects cease to be quantum and become classical. He believed that it was not a question of physics, but one of philosophy.
conscious observer is what makes the wave function collapse. However, this is a minority view among quantum philosophers, considering it a misunderstanding.[46] There are other possible solutions to the "Wigner's friend" thought experiment, which do not require consciousness to be different from other physical processes. Moreover, Wigner shifted to those interpretations in his later years.[47]
The structure of the multiverse, the nature of each universe within it and the relationship between the various constituent universes, depend on the specific multiverse hypothesis considered. Multiverses have been hypothesized in cosmology, physics, astronomy, religion, philosophy, transpersonal psychology and fiction, particularly in science fiction and fantasy. In these contexts, parallel universes are also called "alternative universes", "quantum universes", "interpenetrating dimensions", "parallel dimensions", "parallel worlds", "alternative realities", "alternative timelines", and "dimensional planes", among others.
In several theories, there is a series of, in some cases infinite, self-sustaining cycles – typically a series of Big Crunches (or Big Bounces). However, the respective universes do not exist at once but are forming or following in a logical order or sequence., with key natural constituents potentially varying between universes (see § Anthropic principle).
Robert Dicke, that the range of possible observations that could be made about the universe is limited by the fact that observations could happen only in a universe capable of developing intelligent life.[50] Proponents of the anthropic principle argue that it explains why the universe has the age and the fundamental physical constants necessary to accommodate conscious life, since if either had been different, no one would have been around to make observations. Anthropic reasoning is often used to deal with the idea that the universe seems to be finely tuned for the existence of life.[51]
Personal and collective reality
Each individual has a different view of reality, with different memories and personal history, knowledge, personality traits and experience.[52] This system, mostly referring to the human brain, affects cognition and behavior and into this complex new knowledge, memories,[53] information, thoughts and experiences are continuously integrated.[54][additional citation(s) needed] The connectome – neural networks/wirings in brains – is thought to be a key factor in human variability in terms of cognition or the way we perceive the world (as a context) and related features or processes.[55][56][57]Sensemaking is the process by which people give meaning to their experiences and make sense of the world they live in. Personal identity is relating to questions like how a unique individual is persisting through time.
Sensemaking and determination of reality also occurs collectively, which is investigated in social epistemology and related approaches. From the collective intelligence perspective, the intelligence of the individual human (and potentially AI entities) is substantially limited and advanced intelligence emerges when multiple entities collaborate over time.[58][additional citation(s) needed]Collective memory is an important component of the social construction of reality[59] and communication and communication-related systems, such as media systems, may also be major components (see #Technology).
Philosophy of perception raises questions based on the evolutionary history of humans' perceptual apparatuses, particularly or especially individuals'
physiological senses, described as "[w]e don't see reality — we only see what was useful to see in the past", partly suggesting that "[o]ur species has been so successful not in spite of our inability to see reality but because of it".[60]
Scientific theories of everything
A
unsolved problems in physics
.
Initially, the term "theory of everything" was used with an ironic connotation to refer to various overgeneralized theories. For example, a great-grandfather of
of elementary particle physics – which includes quantum mechanics – for electromagnetism, the two nuclear interactions, and the known elementary particles.
Current candidates for a theory of everything include
Media – such as news media, social media, websites including Wikipedia,[64] and fiction[65] – shape individuals' and society's perception of reality (including as part of belief and attitude formation)[65] and are partly used intentionally as means to learn about reality. Various technologies have changed society's relationship with reality such as the advent of radio and TV technologies.
Research investigates interrelations and effects, for example aspects in the social construction of reality.[66] A major component of this shaping and representation of perceived reality is agenda, selection and prioritization – not only (or primarily) the quality, tone and types of content – which influences, for instance, the public agenda.[67][68] Disproportional news attention for low-probability incidents – such as high-consequence accidents – can distort audiences' risk perceptions with harmful consequences.[69] Various biases such as false balance, public attention dependence reactions like sensationalism and domination by "current events",[70] as well as various interest-driven uses of media such as marketing can also have major impacts on the perception of reality. Time-use studies found that e.g. in 2018 the average U.S. American "spent around eleven hours every day looking at screens".[71]
A filter bubble or ideological frame is a state of intellectual isolation[72] that can result from personalized searches, recommendation systems, and algorithmic curation. The search results are based on information about the user, such as their location, past click-behavior, and search history.[73] Consequently, users become separated from information that disagrees with their viewpoints, effectively isolating them in their own cultural or ideological bubbles, resulting in a limited and customized view of the world.[74] The choices made by these algorithms are only sometimes transparent.[75] Prime examples include Google Personalized Search results and Facebook's personalized news-stream.
A filter bubble has been described as exacerbating a phenomenon that called
ideological frames"[80] and "the figurative sphere surrounding you as you search the internet."[81]
Virtual reality and cyberspace
Virtual reality (VR) is a computer-simulated environment that can simulate physical presence in places in the real world, as well as in imaginary worlds.