Reality (German: Wirklichkeit, French: réalité) has been defined in widely different ways, ranging from denoting an (ontological) transexperiential realm to referring to the totality of one’s (subjective) experiences. Yet others consider reality to be the (social) realm of things and events created and caused by humans.
^ History
In the philosophical discourse, one has first to distinguish the reality of universals (abstract entities) from the reality of (physical) entities. According to Plato’s realism of universals, invariant ideas such as mathematical objects, abstract individual notions and properties have an existence. Since it is they that confer certain properties on physical things, they exist before and independent of physical objects. They are called “universalia ante res.” Aristotle disputed the existence of non-instantiated universals. He claimed that they have to be realized in concrete objects first (“universalia in rebus”).
The Scholasticism of the Middle Ages was dominated by the “problem of universals,” i.e., the metaphysical question of whether universals exist. As a result, the position of nominalism was established. Its adherents assert that everything that exists is concrete, individual and particular, whereas universals (properties, qualities, relations, numbers, classes, sets, etc.) are not real. This position was advocated by, among others, William of Occam for whom universals were just labels we ascribe to classes of experiences.
The Greek sophists and skepticists were among the first who reflected on the reality of physical entities. And since at least René Descartes’ methodical doubt, it has no longer been considered self-evident that there are objects that exist independent of mental processes or that can be referred to, as demanded by metaphysical realism. This opens the door for a subject–object dualism for which a wide range of interpretations and explanations have been provided. At its extremes we find materialism (which denies the nonmaterial character of mental processes) and idealism (or solipsism), which denies the existence of material objects independent of an individual’s mental world.
George Berkley’s “esse est percipi” (to be is to be perceived) summarizes his view that only perceptions and perceiving subjects exists. On the one hand, Berkeley agreed with John Locke’s philosophy, saying that knowledge is solely based on ideas, but disagreed with Locke’s claim that these ideas come from interacting with empirical reality. Berkeley denied the possibility of being able to know such a reality directly as we are only able to know secondary qualities, i.e., our own perceptions. Consequently, he suggested that reality is a phenomenon of human consciousness. This position is known as epistemological idealism.
Giambattista Vico referred to the perceivability of reality in his principle “verum ipsum factum est” (the truth is the same as the made). He claimed that truth can only be seen in the act of making and producing rather than by mere observation, as had been put forward by Descartes. This implies that only God, being its creator, can perceive the real world.
Early proponents of a realist conception of reality were Galileo Galilei and Thomas Reid. In the Platonist vain, Galileo claimed that perception can, at best, provide us with hints about the nature of reality, while its ultimate explanation must be sought in terms of mathematical order, which will reveal true knowledge of primary qualities. For Galileo, secondary qualities are subject to illusion. According to Reid, assuming perceptions would accurately reflect reality is reason for being “clapped into a madhouse.”
Immanuel Kant attempted to bridge the gap between realism and idealism by declaring space and time as forms of intuition (“Anschauungsformen”) of our consciousness. Like categories (such as causality), which are responsible for the contingency of events, the Anschauungsformen have a priori status. (Later in the 20th century, Konrad Lorenz naturalized the Kantian a prioris. He interpreted them as the result of the phylogenetic development in the animal kingdom.) Since space and time and categories are only forms of our thinking, there cannot be any absolute reality independent of our consciousness. What we believe to be reality are phenomena rather than things in themselves. However, according to Kant, our experiences are as real as our consciousness such that Kant felt committed to the position of empirical realism:
{q All knowledge of things merely from pure understanding or pure reason is nothing but sheer illusion, and only in experience is there truth.}
Kant could embed empirical realism in his transcendental idealism, which claims that the world is “ideal” in the sense of given in consciousness. Since for Kant the scandal of philosophy was its failure to produce a proof for the existence of mind-independent entities (because philosophers have always tried to find reality in the transcendental realm), he proposed a “Copernican Turn” in philosophy according to which “objects must conform to our knowledge” (rather than the other way around), thus radically dismissing any form of determinism of the cognizing individual through outside reality. (Later on this led to the formulation of German Idealism, which was later further extended by Gottlieb Fichte and Georg Wilhelm Friedrich Hegel.)
In contemporary Anglo-Saxon philosophy (of language), realism denotes the view that reality exists independent of our consciousness. In his book Truth and Other Enigmas Michael Dummett (1978) has made this position more precise: Each statement about reality is either true or wrong, independent of our means of knowing it (“objective truth value”).
^ Reality in the sciences
In the sciences, the notion of reality seems dispensable. As Rudolf Carnap (1928a, 1928b) put it, “In the realism controversy, science can take neither an affirmative nor a negative position since the question has no meaning.” His well-known example was that of two geographers debating over the reality of a mountain. For the realist, the mountain “not only has the ascertained geographical properties, but is, in addition, also real” while the idealist claims that “the mountain itself is not real, only our perceptions and conscious processes are real.” Therefore, reality should not be considered part of a theory or paradigm. As soon as scientists speak about reality, they do not do this as such but rather as epistemologists who reflect about their respective disciplines. Within a paradigmatically defined discipline, asking for the truth content of a statement is irrelevant and may even hinder progress. Rather, it is both necessary and sufficient to merely specify the action sequence for producing working closed coherences. This renders any correspondence theory, according to which truth can be determined in terms of correspondence between a scientific statement and reality, superfluous. It is replaced by coherence theory and consensus theory. The former is a language-theoretical concept, which requires coherence among systems of propositions. The latter is a social-theoretical criterion. It considers truth as agreement among members of a (language) community.
Following these lines, in Bas van Fraassen’s (1980) constructive empiricism, theories are instruments for ordering the entities in the phenomenal world. Theories do not refer to reality itself but rather to models whose empirical dimension is isomorphic with the phenomena. The acceptance of a theory depends on its empirical adequacy rather than on its correspondence with reality. Hilary Putnam (1987), after having defended metaphysical realism for many years, also turned away from it and asserted that objects do not have an existence independent of conceptual schemata through which we split the world into objects in the first place. According to his theory of internal realism, several valid descriptions of reality are admissible. They have to be assessed in terms of coherence and acceptability rather than from a “God’s eye perspective” that is unassailable for humans. (Later Putnam turned away from this position, too, and turned to direct realism, which rejects the idea of mental representation).
^ The senses and reality
Ernst Mach (1886, 1912) defined reality as a relational complex of elements (sensations). For Mach, “things” consist of a functional assembly of sense elements (“Empfindungskomplexe”). So what we usually refer to as “things” are thought symbols for a sensational complex of relative stability. Consequently, it is not things (bodies) that are the actual elements of the world but sensations such as colors, sounds, pressures, spaces, and times, as well as moods, emotions, and will. However, Mach did not consider the world as a mere sum of sensations. Rather, he defined the world in terms of “functional relations of the elements.” Also, “psychical” entities such as the self are characterized as sensations that are related to each other in different ways. Mach pressed for the “discovery of functional relations… the dependence of experiences on one another.” Mach’s philosophy was monist; for him a fact is a conscious sensation (1972). From his phenomenological perspective, human cognition does not deal with “things” but rather with sensations. Even the reality of the ego, the starting point of Descartes’ arguments, is doubtful as the “primary fact is not the ego, but the elements (sensations).” The “I” is considered a mere “ideal mental-economical unity, not a real unity.” Following Mach, experiences should not be regarded as effects of an external world extending into consciousness as this leads to metaphysical difficulties. It is not the things that produce sensations, but complexes of sensations that make up bodies. Reality is not populated by mysterious entities whose interactions with the ego produce sensations. Rather, colors, sounds, spaces, times are provisionally the ultimate elements whose connexion science should investigate.
^ Fictional reality
In the spirit of Mach’s positivist world-view, Hans Vaihinger (1911) maintained that all we can be certain of are sensations. However, the fact of living in a society and the individual’s attempt to avoid the chaotic subjectivity of knowing only present perceptual impressions compel humans to confer meaning on their sensations. Therefore, they invent concepts and terms and start acting “as if” (“als ob”) these concepts and terms were in true correspondence with reality (“Realität an sich”). Following Berkeley’s skepticism, Vaihinger claimed that this correspondence, however, cannot not be verified. Like the pragmatists such as William James, Vaihinger emphasized the usefulness of these fictions, which also apply to science, of which it is wrong to assume that “its ideas are concerned with reality itself.” Rather science and mathematics are populated with fictions such as imaginary numbers and infinity. However, while for the pragmatist any useful concept is also true, in the fictionalist philosophy, demonstrably false concepts can also still be useful. His prominent example is the concept of free will, which according to Vaihinger is false, but which offers benefits to those who act as if it were true, making ethics and the legal system possible in the first place. However, there is no way to know whether or not these fictions happen to be true images of reality.
^ Subjective reality
In the early 20th century, Jakob von Uexküll (1928, 1934) argued that “all reality is subjective appearance.” He showed that biological organisms live in self-generated environments (“Umwelt”) that are the result of the organism’s abstraction from experience and that depend on the operations of distinction and coordination the organism is able to carry out. The umwelten do not intersect and are therefore incomparable.
Also Ernst von Glasersfeld (1974, 1979, 1991), following the tradition of skepticism, criticized the realists’ assumption that we can determine the truth content of our knowledge by comparing it with reality. If this was correct, we would need to know that which we perceive before we perceive it. Instead, von Glasersfeld proposes, reality ”…is a black box with which we can deal remarkably well” and knowledge about it is the result of trying to find regularities in its input–output behavior. In his “radical constructivist” view, the construction of reality is based on the recurrent extraction of repetitive patterns from the stream of experience. That we succeed in recognizing patterns says nothing about any ontological existence of these patterns, so even “if we posit causes for the sense data [...], this does in no way entail that these causes exist in the spatio-temporal or other relational structures into which we have coordinated them.” Therefore knowledge can only fit reality, similar to a picklock fitting a lock, rather than match reality in the sense of an iconic representation of it. The fit describes the capacity of the key rather than the property of the lock. Based on the work of Jean Piaget, von Glasersfeld maintains that it is the continuous and repeated nature of experiences that then gives rise to the belief in the mind-independent “existence” of the regularities. Therefore statements about the world in itself are and can only be statements about our own experiential reality rather than an “ontic” reality. Reality is a network of concepts that so far have proven to be viable in the light of the experiences of the subject because they repeatedly served as a tool for successfully surmounting problems of life or for assimilating complexes of experiences. Constructivists call this “semantic closure”, as reality does not semantically inform the subject.
Radical constructivism receives further support from the work of Humberto Maturana. In his empirical studies of the color perception of pigeons he failed to show that the spectral composition of colors correlates with the activities in the retina of the animals. What he found instead was that the activity of the retina can be connected to the names of colors, which are considered to be rough indicators of how colors are subjectively experienced (Maturana 1968). His conclusions were that the objective of his research had turned to comparing “the activity of the nervous system with the activity of the nervous system” rather than with an external reality. Maturana’s constitutive ontology (“objectivity in parentheses”) defines reality as the domain of reality defined by the distinctions an observer makes in language. For Maturana (1988), reality is the domain of things, and, in this sense, that which can be distinguished is real. Reality, therefore, lies in the domain of descriptions (“consensual domain”): “Such descriptions are not determined by the nature of that described, but by the describer. They cannot therefore reflect an objective reality; they must remain subjective constructions.”
Heinz von Foerster (1973, 1976) made an attempt at accounting for that which appears to us and which we experience as objects. He argued that for an organism, objects are tokens for stable behavior, or “eigen-behaviors,” and they result from the recursion of accounting for the changes in an organism’s sensations by its actions that in turn are described in terms of its sensations. Therefore, what appear to us as objects are equilibriums that determine themselves through circular processes. They reside “exclusively in the subjects own experience of his or her sensorimotor coordination.” This led to the insight that the “nervous system is organized (or it organizes itself) so as to compute a stable reality.”
^ Cognitive reality
In the tradition of Kant’s “Copernican Turn,” which raises the question of how reality and cognition relate to each other, Olaf Diettrich (1989, 2001) offers a reinterpretation of physics in the light of his “theory of cognitive operators.” Diettrich’s theory starts with the insight that properties are defined as “invariants of measurement devices,” i.e., that certain notions in physics can no longer be defined independently of the measurement. He claims that structures of observations also have to be seen as results of measurements of the cognitive operators in the mind. The crucial point is that observation can only be understood as invariants of these cognitive measuring devices. Therefore, they are strictly human-specific, and do not represent independent ontological elements of an outside reality. The notion of truth can no longer be used as a criterion to evaluate physical theories. Instead theory-building must look for consistency. Furthermore, the fact that a different set of cognitive operators brings forth a different cognitive phenotype makes it virtually impossible to communicate with beings equipped with those alternative operators. However, such beings would not necessarily have a less consistent or efficient world-view. Diettrich even goes a step further when drawing the conclusion that there is a homology between the mechanisms that generate mathematical terms and those that generate observational ones. That mathematical equations fit physical observations so well would then no longer be surprising. The concept of reality is only brought about as a “shortcut” in order to secure observations against doubts in situations when quick action is required.
^ The structure of reality
One of the central assumptions of both common sense and realism/naturalism is that the real world is structured. This (metaphysical) assumption about the inherent ontological structure at the basis of (scientific) data sets has been challenged, among others, by James McAllister (1997, 1999, 2003). He argues that any given data set can be interpreted as the sum of any conceivable pattern and a certain noise level. ”[T]here are infinitely many descriptions of any data set as ’Pattern A + noise at m percent’, ’Pattern B + noise at n percent’, and so on, ranging over all conceivable patterns” (“Noise” refers, in an information-theoretical sense, to the purely mathematical discrepancy between a certain pattern and a given data set.) Therefore, all laws and patterns that can be read into a data set have the same status, which means that all of them match the structures of the reality to the same degree. The statement that the world encompasses all possible structures is, however, equivalent to the claim that it does not contain any structure and is, therefore, amorphous, i.e., structureless.
^ Social reality
According to Peter Berger and Thomas Luckmann (1966), social reality is the result of a dialectic process of externalization, objectification, and internalization. By externalizing, subjects create their own institutions as they determine rules that control their lives and interactions. Objectification occurs when people experience social institutions no longer as human products but as something independent. Internalization emerges when people socialize and live according to the rules of their respective society, which are based on institutional agreements. Consequently, humans become products of the society that they create themselves: “Society is a human product. Society is an objective reality. Humans are a product of society.” Language and everyday language have a particular role because they are on the one hand the main media of the social construction of reality, and on the other hand the main media of the imparting of socially constructed reality.
Appealing to reality as the ultimate arbiter of (scientific) disputes is an appeal to the belief that there exists a mind- and culture-independent reality that defines what is true and what is not. There are many social justifications that account for using the notion of reality irrespective of it being a mere metaphysical extrapolation of experiences: (1) Claiming authority by referring to an external truth makes one’s own point of view unassailable (Mitterer 1992). This is a technique also practiced in religious communities. (2) From a political-sociological perspective, referring to reality can be used to justify research expenses, as the true description of reality “is what we are working for and what we spend the taxpayers’ money for” (Weinberg 1998). (3) On the psychological level, claiming the possession of unique objectivity is a means to force others to do what they would not otherwise do themselves (Maturana 1988). (4) Finally, in philosophy, realism is often equated with seriousness and rationality. This is expressed by John Searle (1995), for whom the refutation of arguments against external realism is a “first step in combating irrationality.” It may be worth pointing out, though, that “realism” refers to the patronizing truth standards put forward by an authority. So it is not realism itself but the realists who subdue the “incorrigibles.”
^ Publication history
  • Version 1: Alexander Riegler, 25 March 2020
  • Version 2: Alexander Riegler, 1 December 2020
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