Reality is the sum or aggregate of all that is real or existent within a
system, as opposed to that which is only
imaginary. The term is also used to refer to the ontological status of things, indicating their
existence
Existence is the ability of an entity to interact with reality. In philosophy, it refers to the ontological property of being.
Etymology
The term ''existence'' comes from Old French ''existence'', from Medieval Latin ''existentia/exsistentia' ...
. In
physical terms, reality is the totality of a system, known and unknown.
Philosophical questions about the nature of reality or existence or being are considered under the
rubric of
ontology
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exi ...
, which is a major branch of
metaphysics
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
in the Western philosophical tradition. Ontological questions also feature in diverse branches of philosophy, including the
philosophy of science
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ult ...
,
philosophy of religion
Philosophy of religion is "the philosophical examination of the central themes and concepts involved in religious traditions". Philosophical discussions on such topics date from ancient times, and appear in the earliest known texts concerning ph ...
,
philosophy of mathematics
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in peop ...
, and
philosophical logic. These include questions about whether only physical objects are real (i.e.,
physicalism), whether reality is fundamentally immaterial (e.g.
idealism
In philosophy, the term idealism identifies and describes metaphysical perspectives which assert that reality is indistinguishable and inseparable from perception and understanding; that reality is a mental construct closely connected t ...
), whether hypothetical unobservable entities posited by scientific theories exist, whether a 'God' exists, whether numbers and other
abstract objects
In metaphysics, the distinction between abstract and concrete refers to a divide between two types of entities. Many philosophers hold that this difference has fundamental metaphysical significance. Examples of concrete objects include plants, hum ...
exist, and whether
possible worlds exist.
Epistemology
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Epis ...
is concerned with what can be known or inferred as
likely and how, whereby in the modern world emphasis is put on
reason
Reason is the capacity of consciously applying logic by drawing conclusions from new or existing information, with the aim of seeking the truth. It is closely associated with such characteristically human activities as philosophy, science, ...
,
empirical evidence
Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences ...
and
science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earli ...
as sources and methods to determine or investigate reality.
Related concepts
World views and theories
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.
Certain ideas from physics, philosophy, sociology,
literary criticism, and other fields shape various theories of reality. One such belief is that there simply and literally ''is'' no reality beyond the perceptions or beliefs we each have about reality. Such attitudes are summarized in the popular statement, "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
In analytic philosophy, anti-realism is a position which encompasses many varieties such as metaphysical, mathematical, semantic, scientific, moral and epistemic. The term was first articulated by British philosopher Michael Dummett in an argument ...
– that is, the view that there is no objective reality, whether acknowledged explicitly or not.
Many of the concepts of science and philosophy are often defined
culturally
Culture () is an umbrella term which encompasses the social behavior, institutions, and Social norm, norms found in human Society, societies, as well as the knowledge, beliefs, arts, laws, Social norm, customs, capabilities, and habits of the ...
and
socially. This idea was elaborated by
Thomas Kuhn
Thomas Samuel Kuhn (; July 18, 1922 – June 17, 1996) was an American philosopher of science whose 1962 book '' The Structure of Scientific Revolutions'' was influential in both academic and popular circles, introducing the term ''paradig ...
in his book ''
The Structure of Scientific Revolutions
''The Structure of Scientific Revolutions'' (1962; second edition 1970; third edition 1996; fourth edition 2012) is a book about the history of science by philosopher Thomas S. Kuhn. Its publication was a landmark event in the history, philoso ...
'' (1962). ''
The Social Construction of Reality'', a book about the
sociology of knowledge
The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and the effects that prevailing ideas have on societies. It is not a specialized area of sociology. Instead, it deal ...
written by
Peter L. Berger
Peter Ludwig Berger (17 March 1929 – 27 June 2017) was an Austrian-born American sociologist and Protestant theologian. Berger became known for his work in the sociology of knowledge, the sociology of religion, study of modernization, and theor ...
and
Thomas Luckmann
Thomas Luckmann (; October 14, 1927 – May 10, 2016) was an American-Austrian sociologist of German and Slovene origin who taught mainly in Germany. Born in Jesenice, Kingdom of Yugoslavia, Luckmann studied philosophy and linguistics at the Un ...
, was published in 1966. It explained how knowledge is acquired and used for the comprehension of reality. Out of all the realities, the reality of everyday life is the most important one since our consciousness requires us to be completely aware and attentive to the experience of everyday life.
A priori and a posteriori
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
Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Languages are the primary means by which humans communicate, and may be conveyed through a variety of ...
and culture) and reality.
On the one hand,
ontology
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exi ...
is the study of being, and the central topic of the field is couched, variously, in terms of being, existence, "what is", and reality. The task in ontology is to describe the most general
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
objectivity that have feet in both
metaphysics
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
and
epistemology
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Epis ...
, philosophical discussions of "reality" often concern the ways in which reality is, or is not, in some way ''dependent upon'' (or, to use fashionable
jargon
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a partic ...
, "constructed" out of) mental and cultural factors such as perceptions, beliefs, and other mental states, as well as cultural artifacts, such as religions and
political movements, on up to the vague notion of a common cultural
world view, or .
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.
One can also speak of ''anti''-realism about the same objects. ''
Anti-realism
In analytic philosophy, anti-realism is a position which encompasses many varieties such as metaphysical, mathematical, semantic, scientific, moral and epistemic. The term was first articulated by British philosopher Michael Dummett in an argument ...
'' is the latest in a long series of terms for views opposed to realism. Perhaps the first was
idealism
In philosophy, the term idealism identifies and describes metaphysical perspectives which assert that reality is indistinguishable and inseparable from perception and understanding; that reality is a mental construct closely connected t ...
, so called because reality was said to be in the mind, or a product of our ''ideas''.
Berkeleyan idealism is the view, propounded by the Irish
empiricist George Berkeley, that the objects of perception are actually ideas in the mind. In this view, one might be tempted to say that reality is a "mental construct"; this is not quite accurate, however, since, in Berkeley's view, perceptual ideas are created and coordinated by God. By the 20th century, views similar to Berkeley's were called
phenomenalism. Phenomenalism differs from Berkeleyan idealism primarily in that Berkeley believed that minds, or souls, are not merely ideas nor made up of ideas, whereas varieties of phenomenalism, such as that advocated by
Russell, tended to go farther to say that the mind itself is merely a collection of perceptions, memories, etc., and that there is no mind or soul over and above such
mental event
A mental event is any event that happens within the mind of a conscious individual. Examples include thoughts, feelings, decisions, dreams, and realizations.
Some believe that mental events are not limited to human thought but can be associated ...
s. Finally, anti-realism became a fashionable term for ''any'' view which held that the existence of some object depends upon the mind or cultural artifacts. The view that the so-called external world is really merely a social, or cultural, artifact, called
social constructionism
Social constructionism is a theory in sociology, social ontology, and communication theory which proposes that certain ideas about physical reality arise from collaborative consensus, instead of pure observation of said reality. The theor ...
, is one variety of anti-realism.
Cultural relativism is the view that
social issues such as morality are not absolute, but at least partially
cultural artifact
A cultural artifact, or cultural artefact (see American and British English spelling differences), is a term used in the social sciences, particularly anthropology, ethnology and sociology for anything created by humans which gives informa ...
.
A
correspondence theory of
knowledge
Knowledge can be defined as Descriptive knowledge, awareness of facts or as Procedural knowledge, practical skills, and may also refer to Knowledge by acquaintance, familiarity with objects or situations. Knowledge of facts, also called pro ...
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
The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific ...
can
verify that a statement is true based on the observable evidence that a thing exists. Many humans can point to the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
and say that this
mountain range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...
exists, and continues to exist even if no one is observing it or making statements about it.
Being
The nature of
being is a perennial topic in metaphysics. For, instance
Parmenides taught that reality was a single unchanging Being, whereas
Heraclitus
Heraclitus of Ephesus (; grc-gre, Ἡράκλειτος , "Glory of Hera"; ) was an ancient Greek pre-Socratic philosopher from the city of Ephesus, which was then part of the Persian Empire.
Little is known of Heraclitus's life. He wrot ...
wrote that all things flow. The 20th-century philosopher
Heidegger
Martin Heidegger (; ; 26 September 188926 May 1976) was a German philosopher who is best known for contributions to phenomenology, hermeneutics, and existentialism. He is among the most important and influential philosophers of the 20th centur ...
thought previous philosophers have lost sight the question of Being (qua Being) in favour of the questions of beings (existing things), so that a return to the Parmenidean approach was needed. An
ontological catalogue is an attempt to list the fundamental constituents of reality. The question of whether or not
existence
Existence is the ability of an entity to interact with reality. In philosophy, it refers to the ontological property of being.
Etymology
The term ''existence'' comes from Old French ''existence'', from Medieval Latin ''existentia/exsistentia' ...
is a
predicate has been discussed since the Early Modern period, not least in relation to the
ontological argument for the existence of God
An ontological argument is a philosophical argument, made from an ontological basis, that is advanced in support of the existence of God. Such arguments tend to refer to the state of being or existing. More specifically, ontological arguments a ...
. Existence, ''that'' something is, has been contrasted with ''
essence
Essence ( la, essentia) is a polysemic term, used in philosophy and theology as a designation for the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it ...
'', 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.
Perception
The question of
direct or "naïve" realism, as opposed to
indirect or "representational" realism, arises in the
philosophy of perception
The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world.cf. http://plato.stanford.edu/entries/perception-epi ...
and
of mind out of the debate over the nature of
conscious
Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...
experience;
[Lehar, Steve. (2000)]
The Function of Conscious Experience: An Analogical Paradigm of Perception and Behavior
, ''Consciousness and Cognition''.[Lehar, Steve. (2000)]
, ''The Function of Conscious Experience''. the
epistemological question of whether the world we see around us is the real world itself or merely an internal perceptual copy of that world generated by
neural processes in our brain.
Naïve realism
In philosophy of perception and philosophy of mind, naïve realism (also known as direct realism, perceptual realism, or common sense realism) is the idea that the senses provide us with direct awareness of objects as they really are. When refer ...
is known as ''direct'' realism when developed to counter ''indirect'' or representative realism, also known as
epistemological dualism, 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.
Timothy Leary
Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from bold oracle to publicity hound. He was "a her ...
coined the influential term
Reality Tunnel, by which he means a kind of
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
philosophy of mathematics
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in peop ...
, the best known form of realism about numbers is
Platonic realism
Platonic realism is the philosophical position that universals or abstract objects exist objectively and outside of human minds. It is named after the Greek philosopher Plato who applied realism to such universals, which he considered ideal ...
, which grants them abstract, immaterial existence. Other forms of realism identify mathematics with the concrete physical universe.
Anti-realist stances include
formalism and
fictionalism
Fictionalism is the view in philosophy according to which statements that appear to be descriptions of the world should not be construed as such, but should instead be understood as cases of "make believe", of pretending to treat something as liter ...
.
Some approaches are selectively realistic about some mathematical objects but not others.
Finitism
Finitism is a philosophy of mathematics that accepts the existence only of finite mathematical objects. It is best understood in comparison to the mainstream philosophy of mathematics where infinite mathematical objects (e.g., infinite sets) are ...
rejects
infinite
Infinite may refer to:
Mathematics
* Infinite set, a set that is not a finite set
*Infinity, an abstract concept describing something without any limit
Music
*Infinite (group), a South Korean boy band
*''Infinite'' (EP), debut EP of American m ...
quantities.
Ultra-finitism
In the philosophy of mathematics, ultrafinitism (also known as ultraintuitionism,International Workshop on Logic and Computational Complexity, ''Logic and Computational Complexity'', Springer, 1995, p. 31. strict formalism,St. Iwan (2000),On the U ...
accepts finite quantities up to a certain amount.
Constructivism
Constructivism may refer to:
Art and architecture
* Constructivism (art), an early 20th-century artistic movement that extols art as a practice for social purposes
* Constructivist architecture, an architectural movement in Russia in the 1920s a ...
and
intuitionism are realistic about objects that can be explicitly constructed, but reject the use of the
principle of the excluded middle to prove existence by
reductio ad absurdum
In logic, (Latin for "reduction to absurdity"), also known as (Latin for "argument to absurdity") or ''apagogical arguments'', is the form of argument that attempts to establish a claim by showing that the opposite scenario would lead to absu ...
.
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
In physics and cosmology, the mathematical universe hypothesis (MUH), also known as the ultimate ensemble theory and struogony (from mathematical structure, Latin: struō), is a speculative "theory of everything" (TOE) proposed by cosmologist Max T ...
advanced by
Max Tegmark
Max Erik Tegmark (born 5 May 1967) is a Swedish-American physicist, cosmologist and machine learning researcher. He is a professor at the Massachusetts Institute of Technology and the president of the Future of Life Institute. He is also a scienti ...
. Tegmark's sole postulate is: ''All structures that exist mathematically also exist physically''. That is, in the sense that "in those
orldscomplex enough to contain self-aware substructures
heywill subjectively perceive themselves as existing in a physically 'real' world".
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
Platonism is the philosophy of Plato and philosophical systems closely derived from it, though contemporary platonists do not necessarily accept all of the doctrines of Plato. Platonism had a profound effect on Western thought. Platonism at l ...
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.
Properties
The problem of universals is an ancient problem in
metaphysics
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
about whether
universals exist. Universals are general or abstract qualities, characteristics,
properties
Property is the ownership of land, resources, improvements or other tangible objects, or intellectual property.
Property may also refer to:
Mathematics
* Property (mathematics)
Philosophy and science
* Property (philosophy), in philosophy an ...
, kinds or
relations, such as being male/female, solid/liquid/gas or a certain colour, 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
Platonic realism is the philosophical position that universals or abstract objects exist objectively and outside of human minds. It is named after the Greek philosopher Plato who applied realism to such universals, which he considered ideal ...
and
Aristotelian realism. ''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.
Nominalism and
conceptualism
In metaphysics, conceptualism is a theory that explains universality of particulars as conceptualized frameworks situated within the thinking mind. Intermediate between nominalism and realism, the conceptualist view approaches the metaphysical co ...
are the main forms of anti-realism about universals.
Time and space
A traditional
realist position in
ontology
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exi ...
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.
Kant
Immanuel Kant (, , ; 22 April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers. Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and aest ...
, in the ''
Critique of Pure Reason'', described time as an ''
a priori'' notion that, together with other ''a priori'' notions such as
space, allows us to comprehend
sense experience. Kant denies that either space or time are
substance, entities in themselves, or learned by experience; he holds rather that both are elements of a systematic framework we use to structure our experience. Spatial
measurements are used to
quantify how far apart
objects are, and temporal measurements are used to quantitatively compare the interval between (or duration of)
events
Event may refer to:
Gatherings of people
* Ceremony, an event of ritual significance, performed on a special occasion
* Convention (meeting), a gathering of individuals engaged in some common interest
* Event management, the organization of ev ...
. Although space and time are held to be ''transcendentally ideal'' in this sense, they are also ''empirically real'', i.e. not mere illusions.
Idealist writers such as
J. M. E. McTaggart in ''
The Unreality of Time'' have argued that time is an illusion.
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
The past is the set of all events that occurred before a given point in time. The past is contrasted with and defined by the present and the future. The concept of the past is derived from the linear fashion in which human observers experience ...
, present and
future separately.
*
Presentism holds that the past and future are unreal, and only an ever-changing present is real.
* The
block universe
In the philosophy of space and time, eternalism is an approach to the ontological nature of time, which takes the view that all existence in time is equally ''real'', as opposed to presentism or the growing block universe theory of time, in wh ...
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.
Time, and the related concepts of process and
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
are central to the
system-building metaphysics of
A. N. Whitehead and
Charles Hartshorne
Charles Hartshorne (; June 5, 1897 – October 9, 2000) was an American philosopher who concentrated primarily on the philosophy of religion and metaphysics, but also contributed to ornithology. He developed the neoclassical idea of God and ...
.
Possible worlds
The term "
possible world" goes back to
Leibniz's theory of possible worlds, used to analyse necessity,
possibility, and similar
modal notions.
Modal realism is the view, notably propounded by
David Kellogg Lewis
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". w ...
, that all possible worlds are as real as the actual world. In short: the actual world is regarded as merely one among an infinity, infinite set theory, set of logically possible 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 alethic logic: a proposition is ''necessary'' if it is true in all possible worlds, and ''possible'' if it is true in at least one. The many worlds interpretation of quantum mechanics is a similar idea in science.
Theories of everything (TOE) and philosophy
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.
The System-building metaphysics, "system building" style of
metaphysics
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
attempts to answer ''all'' the important questions in a coherent way, providing a complete picture of the world. Plato and Aristotle could be said to be early examples of comprehensive systems. In the early modern period (17th and 18th centuries), the system-building ''scope'' of philosophy is often linked to the rationalist ''method'' of philosophy, that is the technique of deducing the nature of the world by pure ''a priori'' reason. Examples from the early modern period include the Gottfried Leibniz, Leibniz's Monadology, René Descartes, Descartes's Mind-body dualism, Dualism, Baruch Spinoza, Spinoza's Monism. Georg Wilhelm Friedrich Hegel, Hegel's Absolute idealism and Alfred North Whitehead, Whitehead's Process philosophy were later systems.
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?"
Phenomenology
On a much broader and more subjective level, private experiences, curiosity, inquiry, and the selectivity involved in personal interpretation of events shapes reality as seen by one and only one person and hence is called Phenomenology (philosophy), 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 Spirituality, 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 Greek language, Greek ''phainómenon'', meaning "that which appears", and ''lógos'', meaning "study". In Husserl's conception, phenomenology is primarily concerned with making the structures of consciousness, and 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 narrative, 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
Knowledge can be defined as Descriptive knowledge, awareness of facts or as Procedural knowledge, practical skills, and may also refer to Knowledge by acquaintance, familiarity with objects or situations. Knowledge of facts, also called pro ...
, including scientific knowledge, and could establish philosophy as a "rigorous science".
Husserl's conception of phenomenology has also been criticised and developed by his student and assistant Martin Heidegger, by existentialists like Maurice Merleau-Ponty and Jean-Paul Sartre, and by other philosophers, such as Paul Ricoeur, Emmanuel Levinas, and Dietrich von Hildebrand.
Skeptical hypotheses
![braininvat](https://upload.wikimedia.org/wikipedia/commons/4/4c/Braininvat.jpg)
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 Zhuang Zhou, 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 five minute hypothesis (or omphalos hypothesis or Last Thursdayism) suggests that the world was created recently together with records and traces indicating a greater age.
* The Matrix hypothesis or Simulated reality hypothesis suggest that we might be inside a computer simulation or virtual reality. Related hypotheses may also involve simulations with signals that allow the inhabitant species in virtual or simulated reality to perceive the external reality.
Jain philosophy
Jain philosophy postulates that seven tattva (truths or fundamental principles) constitute reality. These seven ''tattva'' are:
# ''Jiva, Jīva'' – The Soul (Jainism), soul which is characterized by consciousness.
# ''Ajiva, Ajīva'' – The non-soul.
# ''Asrava'' – Influx of Karma in Jainism, karma.
# ''Bandha (Jainism), Bandha'' – The bondage of karma.
# ''Samvara'' – Obstruction of the inflow of karmic matter into the soul.
# ''Nirjara'' – Shedding of karmas.
# ''Moksha (Jainism), 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
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ult ...
, 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 unobservable, not directly observable discussed by scientific theory, scientific theories. Generally, those who are scientific realists state that one can make reliable claims about these entities (viz., that they have the same Ontology, 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
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
.
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. 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).
Local realism is a significant feature of classical mechanics, of general relativity, and of electrodynamics; but quantum mechanics has shown that quantum entanglement is possible. This was rejected by Einstein, who proposed the EPR paradox, but it was subsequently quantified by Bell's inequalities. If Bell's inequalities are violated, either local realism ''or'' counterfactual definiteness must be incorrect; but some physicists dispute that experiments have demonstrated Bell's violations, on the grounds that the sub-class of Bells Theorem#Two classes of Bell inequalities, inhomogeneous Bell inequalities has not been tested or due to Bell test loopholes, experimental limitations in the tests. Different interpretation of quantum mechanics, interpretations of quantum mechanics violate different parts of local realism and/or counterfactual definiteness.
Role of the observer in quantum mechanics
The quantum mind–body problem refers to the philosophical discussions of the mind–body problem in the context of quantum mechanics. Since quantum mechanics involves quantum superpositions, which Measurement in quantum mechanics, are not perceived by observers, some interpretations of quantum mechanics place conscious observers in a special position.
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 wave function collapse, 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''.
Heisenberg and Bohr always described quantum mechanics in logical positivism, logical positivist terms. Bohr also took an active interest in the philosophical implications of quantum theories such as his Complementarity (physics), complementarity, for example. 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.
Eugene Wigner reformulated the "Schrödinger's cat" thought experiment as "Wigner's friend" and proposed that the consciousness of an observer is the demarcation line which precipitates Wave function collapse, collapse of the wave function, independent of any realist interpretation. Commonly known as "consciousness causes collapse", this interpretation of quantum mechanics states that observation by a conscious observer is what makes the wave function collapse.
Multiverse
The multiverse is the hypothetical set of multiple possible universes (including the historical universe we consistently experience) that together comprise everything that Existence, exists: the entirety of
space, time, matter, and energy as well as the physical laws and physical constant, constants that describe them. The term was coined in 1895 by the American philosopher and psychologist William James. In the many-worlds interpretation (MWI), one of the mainstream interpretations of quantum mechanics, there are an infinite number of universes and every possible quantum outcome occurs in at least one universe, albeit there is Many-worlds interpretation#Debate whether the other worlds are real, a debate as to how real the (other) worlds are.
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.
Anthropic principle
Personal and collective reality
![White Matter Connections Obtained with MRI Tractography](https://upload.wikimedia.org/wikipedia/commons/f/f2/White_Matter_Connections_Obtained_with_MRI_Tractography.png)
Each individual has a different Point of view (philosophy), view of reality, with different memories and personal history, knowledge, personality traits and experience. This system, mostly referring to the human brain, affects cognition and behavior and into this complex new knowledge integration, knowledge, memories, information, thoughts and experiences are continuously integrated. The connectome – Neuron#Connectivity, 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. Sensemaking or sense-making is the process by which people give Semantics, meaning to their experiences and make sense of the world they live in.
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 AI entities) is substantially limited and advanced intelligence emerges when multiple entities collaborate over time. Collective memory is an important component of the social construction of reality and communication and communication-related systems, such as media systems, may also be major components .
Scientific theories of everything
A theory of everything (TOE) is a putative theory of theoretical physics that fully explains and links together all known physical phenomena, and predicts the outcome of ''any'' experiment that could be carried out ''in principle''. The theory of everything is also called the final theory. Many candidate theories of everything have been proposed by theoretical physicists during the twentieth century, but none have been confirmed experimentally. The primary problem in producing a TOE is that general relativity and quantum mechanics are hard to unify. This is one of the 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 Ijon Tichy, a character from a cycle of Stanisław Lem's science fiction stories of the 1960s, was known to work on the "General Theory of Everything". Physicist John Ellis (physicist, born 1946), John Ellis claims to have introduced the term into the technical literature in an article in ''Nature (magazine), Nature'' in 1986. Over time, the term stuck in popularizations of quantum physics to describe a theory that would unify or explain through a single model the theories of all fundamental interactions and of all particles of nature: general relativity for gravitation, and the Standard Model, standard model 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 string theory, M theory, and loop quantum gravity.
Technology
Media
Media – such as news media, social media, websites including Wikipedia, and fiction
– shape individuals' and society's perception of reality (including as part of belief and attitude formation)
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. A major component of this shaping and representation of perceived reality is Agenda-setting theory, agenda, selection and prioritization – not only (or primarily) the quality, tone and types of content – which influences, for instance, the public agenda. Disproportional news attention for low-probability incidents – such as high-consequence aviation accidents – can distort audiences' risk perceptions with harmful consequences. Various biases such as false balance, public attention dependence reactions like sensationalism and domination by "current events", as well as various interest-driven uses of media such as marketing can also have major impacts on the perception of reality. Time-use research, Time-use studies found that e.g. in 2018 the average U.S. American "spent around eleven hours every day looking at screens".
False social reality
''False social reality'' refers to widespread beliefs that are shown to be false. A study introduced the concept, showing that (a sample of) Climate change in the United States, Americans widely Public opinion on climate change, underestimate general Climate communication, public support for climate change mitigation policies by a large margin.
Filter bubbles and echo chambers
Virtual reality and cyberspace
Virtual reality (VR) is a Computer simulation, computer-simulated environment that can simulate physical presence in places in the real world, as well as in imaginary worlds.
![Virtuality continuum 2-en](https://upload.wikimedia.org/wikipedia/commons/c/c7/Virtuality_continuum_2-en.svg)
The virtuality continuum is a continuous scale ranging between the completely virtual, a Virtual reality, virtuality, and the completely real: reality. The reality–virtuality continuum therefore encompasses all possible variations and compositions of real and Virtuality, virtual objects. It has been described as a concept in new media and computer science, but in fact it could be considered a matter of anthropology. The concept was first introduced by Paul Milgram.
The area between the two extremes, where both the real and the virtual are mixed, is the so-called mixed reality. This in turn is said to consist of both augmented reality, where the virtual augments the real, and augmented virtuality, where the real augments the virtual.
Cyberspace, the world's computer systems considered as an interconnected whole, can be thought of as a virtual reality; for instance, it is portrayed as such in the cyberpunk fiction of William Gibson and others. ''Second Life'' and MMORPGs such as ''World of Warcraft'' are examples of artificial environments or virtual worlds (falling some way short of full virtual reality) in cyberspace.
"RL" in internet culture
On the Internet, "real life" refers to life in the real world. It generally references Conditio humana, life or consensus reality, in contrast to an environment seen as fiction or fantasy, such as virtual reality, lifelike experience, dreams, novels, or movies. Online, the acronym "IRL" stands for "in real life", with the meaning "not on the Internet".
Sociologists engaged in the study of the Internet have determined that someday, a distinction between online and real-life worlds may seem "quaint", noting that certain types of online activity, such as sexual intrigues, have already made a full transition to complete legitimacy and "reality".
The abbreviation "RL" stands for "real life". For example, one can speak of "meeting in RL" someone whom one has met in a online chat, chat or on an Internet forum. It may also be used to express an inability to use the Internet for a time due to "RL problems".
See also
* Alternate history
* Counterfactual history
* Derealization
* Extended modal realism
*
Modal realism
* Hyperreality
Notes
References
*
*
Alt URL
Further reading
* George Musser, "Virtual Reality: How close can physics bring us to a truly fundamental understanding of the world?", ''Scientific American'', vol. 321, no. 3 (September 2019), pp. 30–35. "Physics is... the bedrock of the broader search for truth.... Yet [physicists] sometimes seem to be struck by a collective impostor syndrome.... Truth can be elusive even in the best-established theories. Quantum mechanics is as well tested a theory as can be, yet its interpretation remains inscrutable. [p. 30.] The deeper physicists dive into reality, the more reality seems to evaporate." [p. 34.]
External links
*
C.D. Broad on RealityVideo: Animated version of the above with Dr Quantum – FlatlandPhenomenology Online: Materials discussing and exemplifying phenomenological research
{{Authority control
Reality,
Abstraction
Concepts in ancient Greek aesthetics
Concepts in ancient Greek metaphysics
Concepts in ancient Greek philosophy of mind
Concepts in epistemology
Concepts in logic
Concepts in metaphilosophy
Concepts in the philosophy of language
Concepts in the philosophy of science
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Emergence
Empiricism
Epistemological theories
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Ontology
Religion
Philosophical logic
Philosophy of logic
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Qualia
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