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Thursday, October 9, 2025

Scientific realism

From Wikipedia, the free encyclopedia

Scientific realism is the philosophical view that the universe described by science (including both observable and unobservable aspects) exists independently of our perceptions, and that verified scientific theories are at least approximately true descriptions of what is real. Scientific realists typically assert that science, when successful, uncovers true (or approximately true) knowledge about nature, including aspects of reality that are not directly observable.

Within philosophy of science, this view is often an answer to the question "how is the success of science to be explained?" The discussion on the success of science in this context centers primarily on the status of unobservable entities apparently talked about by scientific theories. Generally, those who are scientific realists assert that one can make valid claims about unobservables (viz., that they have the same ontological status) as observables, as opposed to instrumentalism.

In a 2020 PhilPapers Survey 72% of academic philosophers favored scientific realism vs only 15% favoring antirealism.

Main features

Scientific realism involves two basic positions:

  • Ideal-theory thesis. It offers a set of criteria for an ideal scientific theory; one that science aims to approximate.
  • Convergence thesis. It maintains that, in at least some well-established domains, the theories scientists now accept already approximate that ideal and will do so ever more closely as inquiry progresses.

Realists often adopt this thesis selectively; one may be realist about mature fields such as fundamental physics while remaining agnostic about less-settled areas.

An ideal scientific theory, on the realist view, satisfies three interconnected commitments:

  • Semantic: Its central claims are either true or false because they purport to describe the real world.
  • Metaphysical: The entities it posits (e.g. electrons, genes) exist objectively and independent of the mind.
  • Epistemic: We have good reason to believe many of those claims because the theory's explanatory and predictive success would be improbable if they were not at least approximately true.

Taken together, the first two commitments imply that an ideal theory makes definite assertions about genuinely exists entities, while the third justifies believing a significant subset of those assertions.

Realists therefore argue that science progresses: later theories generally answer more questions or do so more accurately, thus moving closer, though never necessarily reaching, the ideal of a literally true account of nature.

Characteristic claims

The following claims are typical of those held by scientific realists. Due to the wide disagreements over the nature of science's success and the role of realism in its success, a scientific realist would agree with some but not all of the following positions.

  • The best scientific theories are at least partially true.
  • The best theories do not employ central terms that are non referring expressions.
  • To say that a theory is approximately true is sufficient explanation of the degree of its predictive success.
  • The approximate truth of a theory is the only explanation of its predictive success.
  • Even if a theory employs expressions that do not have a reference, a scientific theory may be approximately true.
  • Scientific theories are in a historical process of progress towards a true account of the physical world.
  • Scientific theories make genuine, existential claims.
  • Theoretical claims of scientific theories should be read literally and are definitively either true or false.
  • The degree of the predictive success of a theory is evidence of the referential success of its central terms.
  • The goal of science is an account of the physical world that is literally true. Science has been successful because this is the goal that it has been making progress towards.

History

Scientific realism is related to much older philosophical positions including rationalism and metaphysical realism. However, it is a thesis about science developed in the twentieth century. Portraying scientific realism in terms of its ancient, medieval, and early modern cousins is at best misleading.

Scientific realism is developed largely as a reaction to logical positivism. Logical positivism was the first philosophy of science in the twentieth century and the forerunner of scientific realism, holding that a sharp distinction can be drawn between theoretical terms and observational terms, the latter capable of semantic analysis in observational and logical terms.

Logical positivism encountered difficulties with:

  • The verificationist theory of meaning—see Hempel (1950).
  • Troubles with the analytic-synthetic distinction—see Quine (1950).
  • The theory-ladenness of observation—see Hanson (1958) Kuhn (1970) and Quine (1960).
  • Difficulties moving from the observationality of terms to observationality of sentences—see Putnam (1962).
  • The vagueness of the observational-theoretical distinction—see G. Maxwell (1962).

These difficulties for logical positivism suggest, but do not entail, scientific realism, and led to the development of realism as a philosophy of science.

Realism became the dominant philosophy of science after positivism. Bas van Fraassen in his book The Scientific Image (1980) developed constructive empiricism as an alternative to realism. He argues against scientific realism that scientific theories do not aim for truth about unobservable entities. Responses to van Fraassen have sharpened realist positions and led to some revisions of scientific realism.

Arguments for and against scientific realism

No miracles argument

One of the main arguments for scientific realism centers on the notion that scientific knowledge is progressive in nature, and that it is able to predict phenomena successfully. Many scientific realists (e.g., Ernan McMullin, Richard Boyd) think the operational success of a theory lends credence to the idea that its more unobservable aspects exist, because they were how the theory reasoned its predictions. For example, a scientific realist would argue that science must derive some ontological support for atoms from the outstanding phenomenological success of all the theories using them.

Arguments for scientific realism often appeal to abductive reasoning or "inference to the best explanation" (Lipton, 2004). For instance, one argument commonly used—the "miracle argument" or "no miracles argument"—starts out by observing that scientific theories are highly successful in predicting and explaining a variety of phenomena, often with great accuracy. Thus, it is argued that the best explanation—the only explanation that renders the success of science to not be what Hilary Putnam calls "a miracle"—is the view that our scientific theories (or at least the best ones) provide true descriptions of the world, or approximately so.

Bas van Fraassen replies with an evolutionary analogy: "I claim that the success of current scientific theories is no miracle. It is not even surprising to the scientific (Darwinist) mind. For any scientific theory is born into a life of fierce competition, a jungle red in tooth and claw. Only the successful theories survive—the ones which in fact latched on to actual regularities in nature." (The Scientific Image, 1980)

It has been argued that the no miracles argument commits the base rate fallacy.

Pessimistic induction

Pessimistic induction, one of the main arguments against realism, argues that the history of science contains many theories once regarded as empirically successful but which are now believed to be false. Additionally, the history of science contains many empirically successful theories whose unobservable terms are not believed to genuinely refer. For example, the effluvium theory of static electricity (a theory of the 16th Century physicist William Gilbert) is an empirically successful theory whose central unobservable terms have been replaced by later theories.

Realists reply that replacement of particular realist theories with better ones is to be expected due to the progressive nature of scientific knowledge, and when such replacements occur only superfluous unobservables are dropped. For example, Albert Einstein's theory of special relativity showed that the concept of the luminiferous ether could be dropped because it had contributed nothing to the success of the theories of mechanics and electromagnetism. On the other hand, when theory replacement occurs, a well-supported concept, such as the concept of atoms, is not dropped but is incorporated into the new theory in some form. These replies can lead scientific realists to structural realism.

Constructivist epistemology

Social constructivists might argue that scientific realism is unable to account for the rapid change that occurs in scientific knowledge during periods of scientific revolution. Constructivists may also argue that the success of theories is only a part of the construction.

However, these arguments ignore the fact that many scientists are not realists. During the development of quantum mechanics in the 1920s, the dominant philosophy of science was logical positivism. The alternative realist Bohm interpretation and many-worlds interpretation of quantum mechanics do not make such a revolutionary break with the concepts of classical physics.

Underdetermination problem

Another argument against scientific realism, deriving from the underdetermination problem, is not so historically motivated as these others. It claims that observational data can in principle be explained by multiple theories that are mutually incompatible. Realists might counter by saying that there have been few actual cases of underdetermination in the history of science. Usually the requirement of explaining the data is so exacting that scientists are lucky to find even one theory that fulfills it. Furthermore, if we take the underdetermination argument seriously, it implies that we can know about only what we have directly observed. For example, we could not theorize that dinosaurs once lived based on the fossil evidence because other theories (e.g., that the fossils are clever hoaxes) can account for the same data.

Incompatible models argument

According to the incompatible models argument, in certain cases the existence of diverse models for a single phenomenon can be taken as evidence of anti-realism. One example is due to Margaret Morrison, who worked to show that the shell model and the liquid-drop model give contradictory descriptions of the atomic nucleus, even though both models are predictive.

Nominalism

From Wikipedia, the free encyclopedia
William of Ockham

In metaphysics, nominalism is the view that universals and abstract objects do not actually exist other than being merely names or labels. There are two main versions of nominalism. One denies the existence of universals—that which can be instantiated or exemplified by many particular things (e.g., strength, humanity). The other version specifically denies the existence of abstract objects as such—objects that do not exist in space and time.

Most nominalists have held that only physical particulars in space and time are real, and that universals exist only post res, that is, subsequent to particular things. However, some versions of nominalism hold that some particulars are abstract entities (e.g., numbers), whilst others are concrete entities – entities that do exist in space and time (e.g., pillars, snakes, and bananas). Nominalism is primarily a position on the problem of universals. It is opposed to realist philosophies, such as Platonic realism, which assert that universals do exist over and above particulars, and to the hylomorphic substance theory of Aristotle, which asserts that universals are immanently real within them; however, the name "nominalism" emerged from debates in medieval philosophy with Roscellinus.

The term nominalism stems from the Latin nomen, "name". John Stuart Mill summarised nominalism in his aphorism "there is nothing general except names". In philosophy of law, nominalism finds its application in what is called constitutional nominalism.

History

Ancient Greek philosophy

Plato was perhaps the first writer in Western philosophy to clearly state a realist, i.e., non-nominalist, position:

... We customarily hypothesize a single form in connection with each of the many things to which we apply the same name. ... For example, there are many beds and tables. ... But there are only two forms of such furniture, one of the bed and one of the table. (Republic 596a–b, trans. Grube)

What about someone who believes in beautiful things, but doesn't believe in the beautiful itself ...? Don't you think he is living in a dream rather than a wakened state? (Republic 476c)

The Platonic universals corresponding to the names "bed" and "beautiful" were the Form of the Bed and the Form of the Beautiful, or the Bed Itself and the Beautiful Itself. Platonic Forms were the first universals posited as such in philosophy.

Our term "universal" is due to the English translation of Aristotle's technical term katholou which he coined specially for the purpose of discussing the problem of universals. Katholou is a contraction of the phrase kata holou, meaning "on the whole".

Aristotle famously rejected certain aspects of Plato's Theory of Forms, but he clearly rejected nominalism as well:

... 'Man', and indeed every general predicate, signifies not an individual, but some quality, or quantity or relation, or something of that sort. (Sophistical Refutations xxii, 178b37, trans. Pickard-Cambridge)

The first philosophers to explicitly describe nominalist arguments were the Stoics, especially Chrysippus.

Medieval philosophy

In medieval philosophy, the French philosopher and theologian Roscellinus (c. 1050 – c. 1125) was an early, prominent proponent of nominalism. Nominalist ideas can be found in the work of Peter Abelard and reached their flowering in William of Ockham, who was the most influential and thorough nominalist. Abelard's and Ockham's version of nominalism is sometimes called conceptualism, which presents itself as a middle way between nominalism and realism, asserting that there is something in common among like individuals, but that it is a concept in the mind, rather than a real entity existing independently of the mind. Ockham argued that only individuals existed and that universals were only mental ways of referring to sets of individuals. "I maintain", he wrote, "that a universal is not something real that exists in a subject ... but that it has a being only as a thought-object in the mind [objectivum in anima]". As a general rule, Ockham argued against assuming any entities that were not necessary for explanations. Accordingly, he wrote, there is no reason to believe that there is an entity called "humanity" that resides inside, say, Socrates, and nothing further is explained by making this claim. This is in accord with the analytical method that has since come to be called Ockham's razor, the principle that the explanation of any phenomenon should make as few assumptions as possible. Critics argue that conceptualist approaches answer only the psychological question of universals. If the same concept is correctly and non-arbitrarily applied to two individuals, there must be some resemblance or shared property between the two individuals that justifies their falling under the same concept and that is just the metaphysical problem that universals were brought in to address, the starting-point of the whole problem (MacLeod & Rubenstein, 2006, §3d). If resemblances between individuals are asserted, conceptualism becomes moderate realism; if they are denied, it collapses into nominalism.

Modern and contemporary philosophy

In modern philosophy, nominalism was revived by Thomas Hobbes and Pierre Gassendi.

In contemporary analytic philosophy, it has been defended by Rudolf CarnapNelson GoodmanH. H. Price, and D. C. Williams.

Lately, some scholars have been questioning what kind of influences nominalism might have had in the conception of modernity and contemporaneity. According to Michael Allen Gillespie, nominalism profoundly influences these two periods. Even though modernity and contemporaneity are secular eras, their roots are firmly established in the sacred. Furthermore, "Nominalism turned this world on its head," he argues. "For the nominalists, all real being was individual or particular and universals were thus mere fictions."

Another scholar, Victor Bruno, follows the same line. According to Bruno, nominalism is one of the first signs of rupture in the medieval system. "The dismembering of the particulars, the dangerous attribution to individuals to a status of totalization of possibilities in themselves, all this will unfold in an existential fissure that is both objective and material. The result of this fissure will be the essays to establish the nation state."

Indian philosophy

Indian philosophy encompasses various realist and nominalist traditions. Certain orthodox Hindu schools defend the realist position, notably Purva Mimamsa, Nyaya and Vaisheshika, maintaining that the referent of the word is both the individual object perceived by the subject of knowledge and the universal class to which the thing belongs. According to Indian realism, both the individual and the universal exist objectively, with the second underlying the former.

Buddhists take the nominalist position, especially those of the Sautrāntika and Yogācāra schools; they were of the opinion that words have as referent not true objects, but only concepts produced in the intellect. These concepts are not real since they do not have efficient existence, that is, causal powers. Words, as linguistic conventions, are useful to thought and discourse, but even so, it should not be accepted that words apprehend reality as it is.

Dignāga formulated a nominalist theory of meaning called apohavada, or theory of exclusions. The theory seeks to explain how it is possible for words to refer to classes of objects even if no such class has an objective existence. Dignāga's thesis is that classes do not refer to positive qualities that their members share in common. On the contrary, universal classes are exclusions (apoha). As such, the "cow" class, for example, is composed of all exclusions common to individual cows: they are all non-horse, non-elephant, etc.

The problem of universals

Nominalism arose in reaction to the problem of universals, specifically accounting for the fact that some things are of the same type. For example, Fluffy and Kitzler are both cats, or, the fact that certain properties are repeatable, such as: the grass, the shirt, and Kermit the Frog are green. One wants to know by virtue of what are Fluffy and Kitzler both cats, and what makes the grass, the shirt, and Kermit green.

The Platonist answer is that all the green things are green in virtue of the existence of a universal: a single abstract thing that, in this case, is a part of all the green things. With respect to the color of the grass, the shirt and Kermit, one of their parts is identical. In this respect, the three parts are literally one. Greenness is repeatable because there is one thing that manifests itself wherever there are green things.

Nominalism denies the existence of universals. The motivation for this flows from several concerns, the first one being where they might exist. Plato famously held, on one interpretation, that there is a realm of abstract forms or universals apart from the physical world (see theory of the forms). Particular physical objects merely exemplify or instantiate the universal. But this raises the question: Where is this universal realm? One possibility is that it is outside space and time. A view sympathetic with this possibility holds that, precisely because some form is immanent in several physical objects, it must also transcend each of those physical objects; in this way, the forms are "transcendent" only insofar as they are "immanent" in many physical objects. In other words, immanence implies transcendence; they are not opposed to one another. (Nor, in this view, would there be a separate "world" or "realm" of forms that is distinct from the physical world, thus shirking much of the worry about where to locate a "universal realm".) However, naturalists assert that nothing is outside of space and time. Some Neoplatonists, such as the pagan philosopher Plotinus and the Christian philosopher Augustine, imply (anticipating conceptualism) that universals are contained within the mind of God. To complicate things, what is the nature of the instantiation or exemplification relation?

Conceptualists hold a position intermediate between nominalism and realism, saying that universals exist only within the mind and have no external or substantial reality.

Moderate realists hold that there is no realm in which universals exist, but rather there universals are located in space and time however they are manifest. Suppose that a universal, for example greenness, is supposed to be a single thing. Nominalists consider it unusual that there could be a single thing that exists in multiple places simultaneously. The realist maintains that all the instances of greenness are held together by the exemplification relation, but that this relation cannot be explained. Additionally, in lexicology there is an argument against color realism, namely the subject of the blue-green distinction. In some languages the equivalent words for blue and green may be colexified (and furthermore there may not be a straightforward translation either – in Japanese "青", which is usually translated as "blue", is sometimes used for words which in English may be considered as "green" (such as green apples).)

Finally, many philosophers prefer simpler ontologies populated with only the bare minimum of types of entities, or as W. V. O. Quine said "They have a taste for 'desert landscapes.'" They try to express everything that they want to explain without using universals such as "catness" or "greenness."

Varieties

There are various forms of nominalism ranging from extreme to almost-realist. One extreme is predicate nominalism, which states that Fluffy and Kitzler, for example, are both cats simply because the predicate 'is a cat' applies to both of them. And this is the case for all similarity of attribute among objects. The main criticism of this view is that it does not provide a sufficient solution to the problem of universals. It fails to provide an account of what makes it the case that a group of things warrant having the same predicate applied to them.

Proponents of resemblance nominalism believe that 'cat' applies to both cats because Fluffy and Kitzler resemble an exemplar cat closely enough to be classed together with it as members of its kind, or that they differ from each other (and other cats) quite less than they differ from other things, and this warrants classing them together. Some resemblance nominalists will concede that the resemblance relation is itself a universal, but is the only universal necessary. Others argue that each resemblance relation is a particular, and is a resemblance relation simply in virtue of its resemblance to other resemblance relations. This generates an infinite regress, but many argue that it is not vicious.

Class nominalism argues that class membership forms the metaphysical backing for property relationships: two particular red balls share a property in that they are both members of classes corresponding to their properties – that of being red and of being balls. A version of class nominalism that sees some classes as "natural classes" is held by Anthony Quinton.

Conceptualism is a philosophical theory that explains universality of particulars as conceptualized frameworks situated within the thinking mind. The conceptualist view approaches the metaphysical concept of universals from a perspective that denies their presence in particulars outside of the mind's perception of them.

Another form of nominalism is trope nominalism. A trope is a particular instance of a property, like the specific greenness of a shirt. One might argue that there is a primitive, objective resemblance relation that holds among like tropes. Another route is to argue that all apparent tropes are constructed out of more primitive tropes and that the most primitive tropes are the entities of complete physics. Primitive trope resemblance may thus be accounted for in terms of causal indiscernibility. Two tropes are exactly resembling if substituting one for the other would make no difference to the events in which they are taking part. Varying degrees of resemblance at the macro level can be explained by varying degrees of resemblance at the micro level, and micro-level resemblance is explained in terms of something no less robustly physical than causal power. David Armstrong, perhaps the most prominent contemporary realist, argues that such a trope-based variant of nominalism has promise, but holds that it is unable to account for the laws of nature in the way his theory of universals can.

Ian Hacking has also argued that much of what is called social constructionism of science in contemporary times is actually motivated by an unstated nominalist metaphysical view. For this reason, he claims, scientists and constructionists tend to "shout past each other".

Mark Hunyadi characterizes the contemporary Western world as a figure of a "libidinal nominalism." He argues that the insistence on the individual will that has emerged in medieval nominalism evolves into a "libidinal nominalism" in which desire and will are conflated.

Mathematical nominalism

A notion that philosophy, especially ontology and the philosophy of mathematics, should abstain from set theory owes much to the writings of Nelson Goodman (see especially Goodman 1940 and 1977), who argued that concrete and abstract entities having no parts, called individuals, exist. Collections of individuals likewise exist, but two collections having the same individuals are the same collection. Goodman was himself drawing heavily on the work of Stanisław Leśniewski, especially his mereology, which was itself a reaction to the paradoxes associated with Cantorian set theory. Leśniewski denied the existence of the empty set and held that any singleton was identical to the individual inside it. Classes corresponding to what are held to be species or genera are concrete sums of their concrete constituting individuals. For example, the class of philosophers is nothing but the sum of all concrete, individual philosophers.

The principle of extensionality in set theory assures us that any matching pair of curly braces enclosing one or more instances of the same individuals denote the same set. Hence {a, b}, {b, a}, {a, b, a, b} are all the same set. For Goodman and other proponents of mathematical nominalism, {a, b} is also identical to {a, {b} }, {b, {a, b} }, and any combination of matching curly braces and one or more instances of a and b, as long as a and b are names of individuals and not of collections of individuals. Goodman, Richard Milton Martin, and Willard Quine all advocated reasoning about collectivities by means of a theory of virtual sets (see especially Quine 1969), one making possible all elementary operations on sets except that the universe of a quantified variable cannot contain any virtual sets.

In the foundations of mathematics, nominalism has come to mean doing mathematics without assuming that sets in the mathematical sense exist. In practice, this means that quantified variables may range over universes of numbers, points, primitive ordered pairs, and other abstract ontological primitives, but not over sets whose members are such individuals. Only a small fraction of the corpus of modern mathematics can be rederived in a nominalistic fashion.

Criticisms

Historical origins of the term

As a category of late medieval thought, the concept of 'nominalism' has been increasingly queried. Traditionally, the fourteenth century has been regarded as the heyday of nominalism, with figures such as John Buridan and William of Ockham viewed as founding figures. However, the concept of 'nominalism' as a movement (generally contrasted with 'realism'), first emerged only in the late fourteenth century, and only gradually became widespread during the fifteenth century. The notion of two distinct ways, a via antiqua, associated with realism, and a via moderna, associated with nominalism, became widespread only in the later fifteenth century – a dispute which eventually dried up in the sixteenth century.

Aware that explicit thinking in terms of a divide between 'nominalism' and 'realism’ emerged only in the fifteenth century, scholars have increasingly questioned whether a fourteenth-century school of nominalism can really be said to have existed. While one might speak of family resemblances between Ockham, Buridan, Marsilius and others, there are also striking differences. More fundamentally, Robert Pasnau has questioned whether any kind of coherent body of thought that could be called 'nominalism' can be discerned in fourteenth century writing. This makes it difficult, it has been argued, to follow the twentieth century narrative which portrayed late scholastic philosophy as a dispute which emerged in the fourteenth century between the via moderna, nominalism, and the via antiqua, realism, with the nominalist ideas of William of Ockham foreshadowing the eventual rejection of scholasticism in the seventeenth century.

Nominalist reconstructions in mathematics

A critique of nominalist reconstructions in mathematics was undertaken by Burgess (1983) and Burgess and Rosen (1997). Burgess distinguished two types of nominalist reconstructions. Thus, hermeneutic nominalism is the hypothesis that science, properly interpreted, already dispenses with mathematical objects (entities) such as numbers and sets. Meanwhile, revolutionary nominalism is the project of replacing current scientific theories by alternatives dispensing with mathematical objects (see Burgess, 1983, p. 96). A recent study extends the Burgessian critique to three nominalistic reconstructions: the reconstruction of analysis by Georg Cantor, Richard Dedekind, and Karl Weierstrass that dispensed with infinitesimals; the constructivist re-reconstruction of Weierstrassian analysis by Errett Bishop that dispensed with the law of excluded middle; and the hermeneutic reconstruction, by Carl Boyer, Judith Grabiner, and others, of Cauchy's foundational contribution to analysis that dispensed with Cauchy's infinitesimals.

Mathematical beauty

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Mathematical_beauty

Mathematical beauty is a type of aesthetic value that is experienced in doing or contemplating mathematics. The testimonies of mathematicians indicate that various aspects of mathematics—including results, formulae, proofs and theories—can trigger subjective responses similar to the beauty of art, music, or nature. The pleasure in this experience can serve as a motivation for doing mathematics, and some mathematicians, such as G.H. Hardy, have characterized mathematics as an art form that seeks beauty. The logician and philosopher Bertrand Russell made a now-famous statement of this position:

Mathematics, rightly viewed, possesses not only truth, but supreme beauty—a beauty cold and austere, like that of sculpture, without appeal to any part of our weaker nature, without the gorgeous trappings of painting or music, yet sublimely pure, and capable of a stern perfection such as only the greatest art can show.

Beauty in mathematics has been subject to examination by mathematicians themselves and by philosophers, psychologists, and neuroscientists. Understanding beauty in general can be difficult because it is a subjective response to sense-experience but is perceived as a property of an external object, and because it may be shaped by cultural influence or personal experience. Mathematical beauty presents additional problems, since the aesthetic response is evoked by abstract ideas which can be communicated symbolically, and which may only be available to a minority of people with mathematical ability and training. The appreciation of mathematics may also be less passive than (for example) listening to music. Furthermore, beauty in mathematics may be connected to other aesthetic or non-aesthetic values. Some authors seem identify mathematical elegance with mathematical beauty; others distinguish elegance as a separate aesthetic value, or as being, for instance, limited to the form mathematical exposition. Beauty itself is often linked to, or thought to be dependent on, the abstractness, purity, simplicity, depth or order of mathematics.

Examples of beautiful mathematics

Results

Starting at e0 = 1, travelling at the velocity i relative to one's position for the length of time π, and adding 1, one arrives at 0. (The diagram is an Argand diagram.)

Euler's identity is often given as an example of a beautiful result:

This expression ties together arguably the five most important mathematical constants (e, i, π, 1, and 0) with the two most common mathematical symbols (+, =). Euler's identity is a special case of Euler's formula, which the physicist Richard Feynman called "our jewel" and "the most remarkable formula in mathematics".

Another example is Fermat's theorem on sums of two squares, which says that any prime number such that can be written as a sum of two square numbers (for example, , , ), which both G.H. Hardy and E.T. Bell thought was a beautiful result.

In a survey in which mathematicians were asked to evaluate 24 theorems for their beauty, the top-rated three theorems were: Euler's equation; Euler's polyhedron formula, which asserts that for a polyhedron with V vertices, E edges, and F faces, ; and Euclid's theorem that there are infinitely many prime numbers, which was also given by Hardy as an example of a beautiful theorem.

Proofs

An example of "beauty in method"—a simple and elegant visual descriptor of the Pythagorean theorem.

Cantor's diagonal argument, which establishes that there are infinite sets which cannot be put into one-to-one correspondence with the infinite set of natural numbers, has been cited by both mathematicians and philosophers as an example of a beautiful proof.

A proof without words for the sum of odd numbers theorem

Visual proofs, such as the illustrated proof of the Pythagorean theorem, and other proofs without words generally, such as the shown proof that the sum of all positive odd numbers up to 2n − 1 is a perfect square, have been thought beautiful.

The mathematician Paul Erdős spoke of The Book, an imaginary infinite book in which God has written down all the most beautiful mathematical proofs. When Erdős wanted to express particular appreciation of a proof, he would proclaim it "straight from The Book!". His rhetorical device inspired the creation of Proofs from THE BOOK, a collection of such proofs, including many suggested by Erdős himself.

Objects

In Plato's Timaeus, the five regular convex polyhedra, called the Platonic solids for their role in this dialogue, are called the "most beautiful" ("κάλλιστα") bodies. In the Timaeus, they are described as having been used by the demiurge, or creator-craftsman who builds the cosmos, for the four classical elements plus the heavens, because of their beauty.

Kepler's Platonic solid model of the solar system

In his 1596 book Mysterium Cosmographicum, Johannes Kepler argued that the orbits of the then-known planets in the Solar System have been arranged by God to correspond to a concentric arrangement of the five Platonic solids, each orbit lying on the circumsphere of one polyhedron and the insphere of another. For Kepler, God had wanted to shape the universe according to the five regular solids because of their beauty, and this explained why there were six planets (according to the knowledge of the time).

Petrie projection of

A more modern example is the exceptional simple Lie group , which has been called "perhaps the most beautiful structure in all of mathematics".

Scientific theories

The mathematical statements of scientific theories, especially in physics, are sometimes considered to be mathematically beautiful. For example, Roger Penrose thought there was a "special beauty" in Maxwell's equations of electromagnetism: 

Einstein's theory of general relativity has been characterized as a work of art, and, among other aesthetic praise, was described by Paul Dirac as having "great mathematical beauty" and by Penrose as having "supreme mathematical beauty".

(There can be more to the beauty of a scientific theory than just its mathematical statement. For example, whether a theory is visualizable or deterministic might have an influence on whether it is seen as beautiful.)

Properties of beautiful mathematics

Many mathematicians and philosophers who have written about mathematical beauty have tried to identify properties or criteria that are conducive to the perception of beauty in a piece of mathematics. It is debated whether beauty can be clarified or explained by such properties: Paul Erdős thought that it was no more possible to convince someone of the beauty of a piece of mathematics than to convince them of the beauty of Beethoven's Ninth Symphony, if they couldn't see it for themselves.

Results

In his 1940 essay A Mathematician's Apology, G. H. Hardy said that a beautiful result, including its proof, possesses three "purely aesthetic qualities", namely "inevitability", "unexpectedness", and "economy". He particularly excluded enumeration of cases as "one of the duller forms of mathematical argument".

In 1997, Gian-Carlo Rota, disagreed with unexpectedness as a necessary condition for beauty and proposed a counterexample:

A great many theorems of mathematics, when first published, appear to be surprising; thus for example some twenty years ago [from 1977] the proof of the existence of non-equivalent differentiable structures on spheres of high dimension was thought to be surprising, but it did not occur to anyone to call such a fact beautiful, then or now.

In contrast, Monastyrsky wrote in 2001:

It is very difficult to find an analogous invention in the past to Milnor's beautiful construction of the different differential structures on the seven-dimensional sphere... The original proof of Milnor was not very constructive, but later E. Briscorn showed that these differential structures can be described in an extremely explicit and beautiful form.

This disagreement illustrates both the subjective nature of mathematical beauty and its connection with mathematical results: in this case, not only the existence of exotic spheres, but also a particular realization of them.

Proofs

Besides Hardy's properties of "unexpectedness", "inevitability", "economy", which he applied to proofs as well as results, mathematicians have customarily thought beautiful proofs that are short and simple.

In the search for an elegant proof, mathematicians often look for different independent ways to prove a result—as the first proof that is found can often be improved. The theorem for which the greatest number of different proofs have been discovered is possibly the Pythagorean theorem, with hundreds of proofs having being published. Another theorem that has been proved in many different ways is the theorem of quadratic reciprocity. In fact, Carl Friedrich Gauss alone had eight different proofs of this theorem, six of which he published.

In contrast, results that are logically correct but involve laborious calculations or consideration of many cases, are not usually considered beautiful, and may be even referred to as ugly or clumsy. For example, Kenneth Appel and Wolfgang Haken's proof of the four color theorem made use of computer checking of over a thousand cases. Philip J. Davis and Reuben Hersh said that when they first heard that about the proof, they hoped it contained a new insight "whose beauty would transform my day", and were disheartened when informed the proof was by case enumeration and computer verification. Paul Erdős said it was "not beautiful" because it gave no insight into why the theorem was true.

Philosophical analysis

Aristotle thought that beauty was found especially in mathematics, writing in the Metaphysics that

those who assert that the mathematical sciences say nothing of the beautiful or the good are in error. For these sciences say and prove a very great deal about them; for if they do not expressly mention them, but prove attributes which are their results or their formulae, it is not true to say that they tell us nothing about them. The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree.

In the twentieth century, some philosophers questioned whether there was genuinely beauty in mathematics. The philosopher of science Rom Harré argued that there were no true aesthetic appraisals of mathematics, but only quasi-aesthetic appraisals. Any mathematical success described by an aesthetic term was a second-order success besides understanding and correctness. In contrast, aesthetic appraisal of a work of art was first-order. Harré considered this to be the difference between a quasi-aesthetic and a genuinely aesthetic appraisal.

Nick Zangwill thought that there were no true aesthetic experiences of mathematics and that a proofs or theories could only be metaphorically beautiful. His argument had two bases. First, he thought that aesthetic properties depended on sensory properties, and so abstract entities could not have aesthetic properties. Second, he thought that proofs, theorems, theories, and so on had purposes such as demonstrating correctness or granting understanding, and that any praise of them reflected only how well they achieved their purpose.

Scientific analysis

Information-theory model

In the 1970s, Abraham Moles and Frieder Nake analyzed links between beauty, information processing, and information theory. In the 1990s, Jürgen Schmidhuber formulated a mathematical theory of observer-dependent subjective beauty based on algorithmic information theory: the most beautiful objects among subjectively comparable objects have short algorithmic descriptions (i.e., Kolmogorov complexity) relative to what the observer already knows. Schmidhuber explicitly distinguishes between beautiful and interesting. The latter corresponds to the first derivative of subjectively perceived beauty: the observer continually tries to improve the predictability and compressibility of the observations by discovering regularities such as repetitions and symmetries and fractal self-similarity. Whenever the observer's learning process (possibly a predictive artificial neural network) leads to improved data compression such that the observation sequence can be described by fewer bits than before, the temporary interesting-ness of the data corresponds to the compression progress, and is proportional to the observer's internal curiosity reward.

Neural correlates

Brain imaging experiments conducted by Semir Zeki, Michael Atiyah and collaborators show that the experience of mathematical beauty has, as a neural correlate, activity in field A1 of the medial orbito-frontal cortex (mOFC) of the brain and that this activity is parametrically related to the declared intensity of beauty. The location of the activity is similar to the location of the activity that correlates with the experience of beauty from other sources, such as visual art or music. Moreover, mathematicians seem resistant to revising their judgment of the beauty of a mathematical formula in light of contradictory opinion given by their peers.

Mathematical beauty and the arts

Music

Examples of the use of mathematics in music include the stochastic music of Iannis Xenakis, the Fibonacci sequence in Tool's Lateralus, counterpoint of Johann Sebastian Bach, polyrhythmic structures (as in Igor Stravinsky's The Rite of Spring), the Metric modulation of Elliott Carter, permutation theory in serialism beginning with Arnold Schoenberg, and application of Shepard tones in Karlheinz Stockhausen's Hymnen. They also include the application of Group theory to transformations in music in the theoretical writings of David Lewin.

Visual arts

Diagram from Leon Battista Alberti's 1435 Della Pittura, with pillars in perspective on a grid

Examples of the use of mathematics in the visual arts include applications of chaos theory and fractal geometry to computer-generated art, symmetry studies of Leonardo da Vinci, projective geometries in development of the perspective theory of Renaissance art, grids in Op art, optical geometry in the camera obscura of Giambattista della Porta, and multiple perspective in analytic cubism and futurism.

Sacred geometry is a field of its own, giving rise to countless art forms including some of the best known mystic symbols and religious motifs, and has a particularly rich history in Islamic architecture. It also provides a means of meditation and comtemplation, for example the study of the Kaballah Sefirot (Tree Of Life) and Metatron's Cube; and also the act of drawing itself.

The Dutch graphic designer M. C. Escher created mathematically inspired woodcuts, lithographs, and mezzotints. These feature impossible constructions, explorations of infinity, architecture, visual paradoxes and tessellations.

Some painters and sculptors create work distorted with the mathematical principles of anamorphosis, including South African sculptor Jonty Hurwitz.

Origami, the art of paper folding, has aesthetic qualities and many mathematical connections. One can study the mathematics of paper folding by observing the crease pattern on unfolded origami pieces.

British constructionist artist John Ernest created reliefs and paintings inspired by group theory. A number of other British artists of the constructionist and systems schools of thought also draw on mathematics models and structures as a source of inspiration, including Anthony Hill and Peter Lowe. Computer-generated art is based on mathematical algorithms.

Aesthetics

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Aesthetics

Aesthetics[a] is the branch of philosophy that studies beauty, taste, and related phenomena. In a broad sense, it includes the philosophy of art, which examines the nature of art, artistic creativity, the meanings of artworks, and audience appreciation.

Aesthetic properties are features that influence the aesthetic appeal of objects. They include aesthetic values, which express positive or negative qualities, like the contrast between beauty and ugliness. Philosophers debate whether aesthetic properties have objective existence or depend on the subjective experiences of observers. According to a common view, aesthetic experiences are associated with disinterested pleasure detached from practical concerns. Taste is a subjective sensitivity to aesthetic qualities, and differences in taste can lead to disagreements about aesthetic judgments.

Artworks are artifacts or performances typically created by humans, encompassing diverse forms such as painting, music, dance, architecture, and literature. Some definitions focus on their intrinsic aesthetic qualities, while others understand art as a socially constructed category. Art interpretation and criticism seek to identify the meanings of artworks. Discussions focus on elements such as what an artwork represents, which emotions it expresses, and what the author's underlying intent was.

Diverse fields investigate aesthetic phenomena, examining their roles in ethics, religion, and everyday life as well as the psychological processes involved in aesthetic experiences. Comparative aesthetics analyzes the similarities and differences between traditions such as Western, Indian, Chinese, Islamic, and African aesthetics. Aesthetic thought has its roots in antiquity but only emerged as a distinct field of inquiry in the 18th century when philosophers systematically engaged with its foundational concepts.

Definition

A man admiring a painting
The nature of aesthetic experiences, like the admiration of artworks, is a central topic of aesthetics.

Aesthetics, sometimes spelled esthetics, is the systematic study of beauty, art, and taste. As a branch of philosophy, it examines which types of aesthetic phenomena there are, how people experience them, and how objects evoke them. This field also investigates the nature of aesthetic judgments, the meaning of artworks, and the problem of art criticism. Key questions in aesthetics include "What is art?", "Can aesthetic judgments be objective?", and "How is aesthetic value related to other values?". One characterization distinguishes between three main approaches to aesthetics: the study of aesthetic concepts and judgments, the study of aesthetic experiences and other mental responses, and the study of the nature and features of aesthetic objects. In a slightly different sense, the term aesthetics can also refer to particular theories of beauty or to beautiful appearances.

Aesthetics is closely related to the philosophy of art and the two terms are often used interchangeably since both involve the philosophical study of aesthetic phenomena. One difference is that the philosophy of art focuses on art, whereas the scope of aesthetics also includes other domains, such as beauty in nature and everyday life. This leads some theorists to argue that the philosophy of art is a subfield of aesthetics. However, the precise relation between the two fields is disputed and another characterization holds that the philosophy of art is the broader discipline. This view argues that aesthetics mainly addresses aesthetic properties, while the philosophy of art also investigates non-aesthetic features of artworks, belonging to fields such as metaphysics, epistemology, philosophy of language, and ethics.

Even though the philosophical study of aesthetic problems originated in antiquity, it was not until the 18th century that aesthetics emerged as a distinct branch of philosophy when philosophers engaged in systematic inquiry into its principles. The term "aesthetics" was coined by the German philosopher Alexander Baumgarten in 1735, initially defined as the study of sensibility or sensations of beautiful objects. The term comes from the ancient Greek words aisthetikos, meaning 'perceptible things', aisthesthai, meaning 'perceive, see', and aisthesis, meaning 'sensation, perception'. The earliest known use in the English language happened in a translation by W. Hooper in the 1770s.

Basic concepts

The domain of the aesthetic encompasses a variety of properties, objects, experiences, and judgments associated with beauty and artistic expression. However, the exact boundaries of this domain are disputed—it is controversial whether there is a group of essential features shared by all aesthetic phenomena or whether they are more loosely related through family resemblances. Another central topic concerns the relation between different aesthetic concepts, for example, whether the concept "aesthetic object" is defined through the concept of "aesthetic experience".

Aesthetic properties and objects

Aesthetic properties of an object are features that shape its aesthetic appeal or factors that influence aesthetic evaluations. For instance, when an art critic describes an artwork as great, vivid, or amusing, they express aesthetic properties of this artwork. Some aesthetic properties focus on aesthetic value in general, like beautiful and ugly, while others center on more specific forms of value, such as graceful and elegant. Aesthetic properties can also refer to perceptual qualities of objects like balanced and vivid, to representational aspects like realistic and distorted, or to emotional responses such as joyful and angry.

The precise distinction between aesthetic and non-aesthetic properties is disputed. According to one proposal, aesthetic properties require a specific aesthetic sensitivity in addition to the sensory perception of non-aesthetic properties, going beyond simple colors, shapes, and sounds. Aesthetic properties are associated with evaluations, but not all are intrinsically good or bad. For example, being a realistic representation may be aesthetically good in some artistic contexts and bad in others.

Diagram of a person looking at a flower with the labels "aesthetic experience", "aesthetic attitude", and "aesthetic object"
Diagram of the relation between aesthetic concepts. Philosophers debate whether aesthetic objects are material or intentional objects.

The school of realism argues that aesthetic properties are objective, mind-independent features of reality. A related proposal asserts that they are emergent properties dependent on non-aesthetic properties. According to this view, the beauty of a painting may emerge from the right combination of colors and shapes. A different position holds that aesthetic properties are response-dependent, for example, that features of objects only qualify as aesthetic properties if they evoke aesthetic experiences in observers. The terms "aesthetic property" and "aesthetic quality" are often used interchangeably to refer to aspects such as beauty, sublimity, and grandeur. However, some philosophers distinguish the two, associating aesthetic properties with objective features and aesthetic qualities with subjective experiences and emotional responses.

An aesthetic object is an object with aesthetic properties. One interpretation suggests that aesthetic objects are material entities that evoke aesthetic experiences. According to this view, if a person admires an oil painting then the physical canvas and paint make up the aesthetic object. Another interpretation, associated with the school of phenomenology, argues that aesthetic objects are not material but intentional objects. Intentional objects are part of the content of experiences and their existence depends on the perceiver. An intentional object may accurately reflect a material object, as in the case of veridical perceptions, but can also fail to do so, which happens during perceptual illusions. The phenomenological perspective focuses on the intentional object given in experience rather than the material object considered independently of the perceiver.

Aesthetic values and beauty

Aesthetic values are a special type of aesthetic properties. They express the sensory appeal of an object as a qualitative measure of its aesthetic merit. Aesthetic values contrast with values in other domains, such as moral, epistemic, religious, and economic values. Beauty is usually considered the main aesthetic value, but not the only one. For example, the sublime is another value of things that inspire a feeling of awe and fear. Further suggested values include charm, elegance, harmony, and grace. Historically, pre-modern philosophers typically rejected the idea of multiple distinct aesthetic values. They tended to argue that beauty alone encompasses all that is aesthetically commendable and serves as a unifying concept of the whole domain of aesthetics. Aesthetic values are either positive, like beautiful and sublime, or negative, such as clumsy and boring. Various attempts have been made to explain why some objects have positive aesthetic values, proposing features like unity, intensity, and the right level of complexity.

The aesthetic value of beauty is often singled out as a central topic of aesthetics. It is a key aspect of human experience, influencing both personal decisions and cultural developments. Often-cited examples of beautiful objects include landscapes, sunsets, humans, and artworks. As a positive value, beauty contrasts with ugliness as its negative counterpart. Beauty is typically understood as a quality of objects that involves balance or harmony and evokes admiration or pleasure when perceived, but its precise definition is debated.

Various theoretical disputes surround the nature of beauty and its role in aesthetics. Some theories understand beauty as an objective feature of external objects. Others emphasize its subjective nature, linking it to personal experience and perception. They argue that "beauty is in the eye of the beholder" rather than in the perceived object. Another central debate concerns the features that all beautiful objects have in common. The so-called classical conception of beauty is rooted in classical antiquity and the Italian Renaissance. Focusing on objective features, it asserts that beauty is an harmonious arrangement of parts into a coherent whole. Aesthetic hedonism, by contrast, is a subjective theory holding that a thing is beautiful if it acts as a source of aesthetic pleasure. Other conceptions define beautiful objects in terms of intrinsic value, the manifestation of ideal forms, or as what evokes love and passion.

Aesthetic experiences, attitude, and pleasure

An aesthetic experience is an appreciation of beauty or an awareness of other aesthetic features. In its most typical form, it is a sensory perception of a natural object or an artwork. However, it can also take other forms, such as aesthetic imagination of fictional objects described in literature. Internalist theories, like Monroe Beardsley's view, explain aesthetic experience from a first-person perspective, focusing on aspects internal to the experience, such as focus and intensity. By contrast, externalist theories, such as George Dickie's position, argue that the key element of aesthetic experiences comes from the experienced external objects and their aesthetic properties.

Diverse features are associated with aesthetic experiences, but it is controversial whether any of them are essential. Aesthetic experiences usually appreciate an object for its own sake because of its sensory properties, resulting in aesthetic pleasure from a positive evaluation of the object. This pleasure is typically said to be detached from practical concerns and can involve selfless absorption, allowing imaginative freedom or free play of mental faculties in addition to sensory perception. Some theorists associate this free play with an absence of conceptual activity. Aesthetic experiences may also be normative, meaning that certain responses are appropriate, like the positive appreciation of beauty, but others are not, such as the positive appreciation of ugliness.

A central aspect of aesthetic experience is the aesthetic attitude—a special way of observing or engaging with art and nature. This attitude involves a form of pure appreciation of perceptual qualities detached from personal desires and practical concerns. It is disinterested in this sense by engaging with an object for its own sake without ulterior motives or practical consequences. For example, the experience of a violent storm through the aesthetic attitude may focus on its intricate patterns of lightning and thunder rather than preparing for its immediate dangers. One characterization understands the aesthetic attitude as a natural form of apprehension that occurs on its own in certain situations. Another outlook holds that the aesthetic attitude is a voluntary stance people can choose to adopt towards any object. There is debate about the extent and type of emotional engagement a disinterested stance requires, for instance, whether fear during a horror movie can be disinterested.

The aesthetic attitude is sometimes contrasted with other attitudes, such as the practical attitude, which is interested in usefulness and seeks to utilize or manipulate objects to achieve specific goals. Similarly, it differs from the scientific attitude, which aims to explain phenomena and acquire factual knowledge about the world. Some philosophers, such as Arthur Schopenhauer and Martin Heidegger, suggest that the aesthetic attitude can reveal aspects of reality obscured in other attitudes.

Aesthetic experience is further associated with aesthetic pleasure—a form of enjoyment in response to natural and artistic beauty. It is typically characterized as disinterested pleasure. It contrasts with interested pleasure that arises from the satisfaction of desires, such as the joy of achieving a personal goal or indulging in a particular type of food one craved. Another difference is that aesthetic pleasure does not depend on the existence of the enjoyed object, like enjoying the beauty of a sunset in a dream. The joy in achieving a personal goal, by contrast, would be frustrated if one discovered that the achievement was merely a dream. Philosophers like Immanuel Kant argue that aesthetic pleasure is pre-conceptual, meaning that it arises from a free interplay between imagination and understanding rather than from cognitive judgments or conceptual analysis. Some theorists distinguish refined from unrefined aesthetic pleasures based on whether the pleasure is evoked by a cultivated taste or an immediate, instinctual response.

Aesthetic pleasure is central to the characterization of various aesthetic phenomena, which are said to involve or evoke such pleasure. However, the view that aesthetic pleasure is the defining characteristic of the entire aesthetic domain is controversial. It faces challenges in explaining phenomena such as the sublime, drama, tragedy, and various forms of modern art, which may evoke diverse emotions not primarily linked to pleasure.

Aesthetic judgments and taste

Oil painting of Immanuel Kant
According to Immanuel Kant, aesthetic judgments are subjective, universal, disinterested, and involve an interplay of sense, imagination, and understanding.

Aesthetic judgments are assessments of the aesthetic features and values of objects, expressed in statements like "this music is beautiful". They can apply both to natural objects and artworks. Aesthetic judgments also include assessments about how or why an object has aesthetic value without explicitly determine its overall aesthetic worth, as in the statement "this music is balanced". Many debates in aesthetics concern the nature of aesthetic judgments, in particular, whether they can be as objective and universal as empirical judgments made by natural scientists. Subjectivists argue that aesthetic judgments express personal feelings and dislikes without universal validity. This view is contested by objectivists, who hold that aesthetic judgments describe objective features that are independent of the particular preferences of the judging individual. Intermediate views suggest that the standards of aesthetic judgment are grounded in stable shared dispositions rather than variable individual preferences, resulting in a form of subjective universality. This position is reflected in Kant's view, which identifies four core features of aesthetic judgments: they are subjective, universal, disinterested, and involve an interplay of sense, imagination, and understanding.

Philosophers such as Francis Hutcheson and David Hume argue that there are general aesthetic principles or universal criteria that are applied when making aesthetic judgments. Particularists, by contrast, assert that the unique nature of each aesthetic object requires a case-by-case evaluation that cannot be fully subsumed under general principles. A related debate between rationalism and the immediacy thesis concerns whether aesthetic judgments are mediated through concept application and reasoning or emerge directly from sensory intuition.

Aesthetic judgments rely on taste, which is a sensitivity to aesthetic qualities, a capacity to feel aesthetic pleasure, or an ability to discern beauty and other aesthetic qualities. Taste is a type of preference expressed in immediate reactions and is sometimes understood as an inner sense or cognitive faculty. Differences in taste are often used to explain why people disagree about aesthetic judgments and why the judgments of some people, such as art critics with extensive experience and a refined sense, carry more weight than those of casual observers. Taste varies both between cultures and between individuals within a culture.[e] However, there are also some cross-cultural agreements. Various philosophers argue that taste can be learned to some extent and that the judgments of experienced observers follow similar standards, suggesting the existence of social norms of right and wrong aesthetic assessments.

The term "aesthetic universal" refers to aspects of taste and other aesthetic phenomena that are shared across different cultures and societies, indicating common features of human nature underlying aesthetics. Suggested general tendencies include the dispositions to engage in artistic expressions or to derive aesthetic pleasure from appreciating these expressions. The existence of more specific shared tendencies is debated. An example is the idea that humans generally find savanna-like landscapes with open grassy plains and scattered trees pleasing.

Art

Art is a central topic of aesthetics and the main subject of the philosophy of art. It encompasses diverse forms, including painting, sculpture, music, dance, literature, and theater. This field covers both artworks and the skills or activities involved in their creation. Artworks are artifacts or performances typically created by humans. They differ in this respect from naturally occurring aesthetic objects, like landscapes and sunsets.

Definitions

A central debate in the philosophy of art concerns the definition of art or how to distinguish it from non-art. There are diverse theories, each offering a unique perspective about the nature of art.

Black-and-white photo of a porcelain urinal signed "R. Mutt"
Conventionalist definitions of art assert that art is a socially constructed category. They explain that readymade objects like Marcel Duchamp's Fountain are considered art by reference to established conventions.

Essentialist approaches argue that there is an essence or a set of inherent features shared by all artworks and only by them. They often define artworks in terms of other aesthetic concepts, such as representation, beauty, or aesthetic experience. An early object-centered approach, first proposed by Plato, characterizes artworks as representations that seek to reflect or imitate certain aspects of reality. Another definition suggests that artworks are objects designed to evoke aesthetic experiences or pleasure. A related approach proposes that all artworks have certain aesthetic properties in common, such as beauty. Aesthetic formalism argues that specific formal features, such as a "significant form", are the hallmark of art. Artist-centered approaches see artistic activity as the essential aspect of artworks. One conception understands artworks as special vehicles through which artists express emotions and other mental states.

Conventionalist definitions view art as a socially constructed category. This means that it does not primarily depend on the inherent properties of objects, for example, what they represent or what forms they have. Instead, art is defined by social and cultural agreements, which are subject to change. A key motivation for this approach has been the emergence of modern art, which has challenged many earlier conceptions. Conventionalist definitions can explain, for instance, that even mundane ready-made objects like a urinal are considered art if conventions say so. Institutional theories argue that the conventions are set by social institutions of the art world. Because of this social dependence, an object considered art in one society may not be art in another society. Historical theories, another form of conventionalism, assert that the category of art depends on established traditions and historical contexts. They claim that an object becomes part of this category if it stands in the right relation to these traditions, for example, by being created in an artistic context and resembling other recognized artworks.

There are also hybrid theories that combine elements from other theories. For instance, one approach holds that an object is an artwork if it either meets certain aesthetic standards or is conventionally regarded as art. The diversity of proposed definitions and the difficulties in reconciling them have led some philosophers to argue against the existence of precise criteria. Some conclude that a definition is strictly impossible. Others provide vague characterizations, suggesting that the domain of art is characterized by overlapping similarities, known as family resemblance.

Ontology and categories

The ontology of art seeks to discern the fundamental categories of being to which all artworks belong. Universalists argue that artworks are universals—general or repeatable entities that can have several instances at the same time. For example, a novel can have many copies, a film can have many screenings, and a photo can have many prints. One version of this view distinguishes artworks as types from their instances, which are considered tokens of this type. Particularists reject the idea that artworks are universals, arguing instead that they are particulars or unique concrete entities. For them, if there are several instances then the artwork is the collection or sum of all instances. According to this view, Alfred Stieglitz's photograph The Steerage is not a type underlying its prints but rather the collection or sum of all prints together.

A similar discussion addresses whether artworks are material objects, which exist independent of observers, or intentional objects, which exist in the experience of observers. Pluralists argue that different types of artworks belong to distinct ontological categories. Contextualists accept this view and further propose that the ontological category depends on the context of discussion. Deflationism is skeptical about the fundamental existence of artworks in any form. It acknowledges that the term art may be practically useful in everyday language but rejects that it refers to any fundamental entities of reality.

Photo of various tubes of oil paint
Some categorizations of art forms focus on the medium used to express artistic ideas, such as the use of oil paint.

Artworks are categorized in various ways. Some distinctions focus on the medium used to express artistic ideas. For example, paintings typically use paint, such as oil or acryl paint, which is distributed on a surface, whereas dance involves bodily movements. Similarly, music is performed using instruments and voice to produce sounds, and literature relies on language. Hybrid forms like opera and film combine several of these elements. Another distinction is between performance works and object works. Performance works, like a song performed on stage, are dynamically enacted in time, whereas object works, like a painting, have a more static nature. Artworks can also be classified by style, such as impressionism and surrealism, and by their intended purpose, like political and religious art.

Meaning

The meaning of an artwork is what is involved in understanding it or comprehending what it communicates, encompassing factors such as representation and expression. Certain aspects of meaning may be directly accessible while others require in-depth interpretation, for example, to grasp symbolic or metaphorical elements. Understanding influences aesthetic experience and for certain artworks, a comprehensive understanding may be required to fully appreciate them. One approach to the analysis of meaning is the distinction between form and content. Content refers to what is presented, such as the depicted topic, expressed ideas, and conceptual messages. Form refers to how the content is presented, such as medium, technique, composition, and style. Form encompasses diverse modes of presentation in different art forms, like color and spatial arrangement in painting, harmony and rhythm in music, and narrative voice and plot structure in literature.

Representation and expression

Oil painting of a person screaming against the backdrop of an orange sky
The emotions artworks express are a central topic in the philosophy of art, such as the feelings of alienation and existential dread in Edvard Munch's 1893 painting The Scream.

Representation is a depiction of real or imagined entities. For example, a portrait painting represents a person, while a fantasy novel represents an imaginary chain of events. Similarity is a crucial element in many forms of artistic representation, meaning that the artwork resembles the depicted entity. However, representation can also happen through other means, such as conventional symbols and established codes. It is particularly prevalent in some art forms and styles, such as classical art and realism. Since antiquity, representation has been a key concept in theories of art, such as Plato's idea of defining art as imitation. However, it is controversial whether representation plays a central role in all art forms, including music and abstract modern art.

Expression is the conveyance of psychological states, such as emotions, moods, and attitudes. For example, a painter may depict a barren landscape in muted colors to express sadness, while a musician might use a fast tempo and upbeat melody to convey excitement. The expressed mental states often align with the artist's personal experience. However, this is not necessarily the case and artists may explore psychological states they observed in others or entirely fictional experiences. An artwork can express a mental state like sadness by evoking it in the experience of the audience. Alternatively, the expression can also happen if observers recognize the presence of sadness in the artwork even if they do not personally feel it. Expression theories consider expression a core feature of artworks. They characterize artworks as expressions of the artist's mind, focusing on creativity and originality in the manifestation of aesthetic experiences.

Interpretation and criticism

The process of interpretation is the attempt to uncover the meaning of an artwork to understand its significance and value. In the widest sense, interpretation encompasses any way of assigning meaning, including obvious descriptions of depicted entities and explanations of literal word meanings. In philosophy of art, the term is typically used in a more narrow sense for assignments of meaning that involve deeper analysis and creative thought. Interpretations aim to discover underlying aspects that are relevant to the understanding and appreciation of the artwork. The terms interpretation and criticism are sometimes used interchangeably. However, criticism is typically associated with more components, like a general description of the criticized artwork and a classification of style and genre. Criticism also explains the art-historical background and evaluates positive and negative qualities.

Critics sometimes propose conflicting interpretations of the same artwork. According to critical monism, there is only one comprehensive correct interpretation, implying that conflicting interpretations cannot both be correct. Critical pluralism, by contrast, asserts that there can be different but equally valid interpretations and that it is not always possible to determine which of two conflicting interpretations is superior. A similar issue involves whether interpretations can be true or false in an objective sense.

Various frameworks of interpretation have been proposed. According to intentionalism, the meaning of an artwork is determined by the author's intent—their reasons and motives that led to the creation of the artwork. This typically involves analyzing the ideas the artist aimed to express but can also include a biographical analysis to learn about psychological and social circumstances in the artist's life.

Intentionalism is a controversial theory, termed intentional fallacy by its critics. Some objections point to cases where the author's intention cannot be known, where the author themselves cannot be identified, or where no traditional author exists, as artworks created by artificial intelligence. In these cases, meaning would be inaccessible or non-existent. Other objections assert that an artist may fail to accurately express their intention or may manifest unintended aesthetic features, suggesting that an artwork can contain both less and more than the artist intended.

An alternative to intentionalism argues that meaning is determined by artistic, stylistic, linguistic, and other cultural conventions. For example, linguistic conventions determine the literal meanings of words and thereby influence the overall meaning of a poem. Another framework holds that meaning is shaped by how the audience, rather than the author, interprets or would interprets the intention underlying the work. Artistic formalism proposes a different approach by focusing interpretation exclusively on formal or perceptual features of artworks.

Aestheticism and instrumentalism are theories about the value of art. Aestheticism asserts that the primary value of art lies in its intrinsic aesthetic merits, independent of any external purposes. This idea of the autonomy of art is expressed in the slogan "art for art's sake". Strong forms of aestheticism not only disregard external purposes but see them as detrimental influences that undermine artistic integrity. Instrumentalism, by contrast, explains the value of art by the effects it has on other domains. It understands art as a means to things such as moral education, spiritual growth, therapeutic benefits, and social cohesion.

The individual arts

The individual arts are diverse practices or disciplines in the domain of art. They encompass a wide range of fields, including traditionally established forms such as painting, music, and literature, as well as newer types like video games. One classification divides them into visual arts, literary arts, and performance arts. However, the boundaries between these categories are not always clear, and alternative classifications have been proposed.

Photo of dancing African women
Dance is a performance art involving a series of bodily movements.

Painting is a visual art in which a painter applies colors to a surface. It allows for a diverse range of motives and styles, and is often considered a paradigm form of art. The representation of real entities plays a central role in many forms of painting, ranging from landscapes and people to historic events. This process involves artistic choices that go beyond simple replication, such as guiding the viewer's attention to specific aspects or highlighting important but easily overlooked features. The issue of representation is also crucial in photography, a visual art shaped by technological developments in camera design and editing processes. A key topic in the philosophy of photography concerns its mechanical manner of authentically representing real objects, frequently drawing parallels and distinctions with painting. The status of photographs as true artworks is disputed, with critics arguing that the mechanical nature of capturing images lacks the necessary artistic creativity.

Music is a performance art in which sounds are combined to create aesthetic patterns, relying on aspects such as melody and rhythm. Unlike painting and photography, music is typically less associated with objective representation, having a closer link to the expression of emotions. A key discussion in the philosophy of music revolves around the definition of music or the criteria under which a combination of sounds is music. Proposals range from objective criteria, such as the organization of sounds, to subjective criteria, like the way sounds are interpreted or experienced. Dance is another performance art in which dancers perform a series of bodily movements, often following a choreography. It is typically accompanied by music and shares with music an emphasis on expressive features.

Photo of the Sagrada Família, a cathedral with tall, intricate towers and detailed facades
Architecture is an art that typically combines aesthetic with functional goals, such as Antoni Gaudí's Sagrada Família.

Architecture is the art or craft of designing and building, encompassing a wide range of structures from monuments and cathedrals to skyscrapers and residential homes. It typically combines aesthetic with functional goals, seeking to create buildings that are both visually appealing and practically useful. This dual nature is a central topic of the philosophy of architecture, with one theory suggesting that mere buildings can be distinguished from artistic architecture by the presence of decorative elements. Sculpture is another art form that, like architecture, involves the creation of three-dimensional works. Sculptures are usually static objects made of robust materials like stone, metal, and wood. However, the field of sculpture is broader and covers diverse three-dimensional objects, including kinetic sculptures. Key discussions in the philosophy of sculpture address the definition, representational aspects, and aesthetic features of sculptures as well as the influence of the chosen material.

Literature has language as its primary medium. In its widest sense, literature encompasses any written document. However, the term is typically used in a more narrow sense in aesthetics for forms of writing that belong to the high arts, such as poems, novels, and drama. Literature as an art is often characterized by its deliberate, elaborate, and organized use of language, but there is no universally accepted demarcation between artistic literature and other forms of writing. Poetry is a distinct form of literature often written in verses composed of several lines that may follow specific patterns, such as meter and rhyme. Many poems are characterized by a deliberate economical use of language that seeks to evoke specific experiences while being difficult to paraphrase.

Theater is a performance art that combines elements from other art forms. It typically includes a carefully prepared set or stage where actors perform, usually incorporating storytelling and sound design to create immersive experiences. Theater is performed before a live audience, which can create a sense of immediacy that is less prevalent in related art forms, such as film. Film also integrates aspects from various artistic disciplines but relies more heavily on technological means of recording and editing. Films can involve actors but may also include animated characters or document real-life events. They are normally the result of collaborative efforts of many people, which complicates the identification of a singular author in the traditional sense.

Video games are a more recent form of art. Like theater and film, they usually blend visual, auditory, and narrative elements. They typically stand out through their emphasis on player interaction, allowing active exploration of and engagement with the game world. The status of films and video games as serious forms of art is disputed. Proponents tend to emphasize their aesthetic qualities, while critics often point to their association with mass production and popular culture as counterarguments. For video games, a related debate centers on the elements of competition and winning, questioning whether these elements run counter to the spirit of art.

In various fields

Aesthetic phenomena are investigated in diverse fields. They cover the relation between aesthetics and other branches of philosophy, scientific inquiry using empirical methods, comparisons of different artistic traditions, and the study of aesthetic elements in specific areas of life.

Ethics

Ethics is the branch of philosophy that studies moral phenomena in general and right behavior in particular. Artworks can have various ethical consequences by influencing how people feel, perceive, and evaluate their circumstances. For example, artworks can glorify violence and reinforce biases, just as they can inspire empathy and challenge societal norms. As a result, art is also relevant to the field of politics since it can steer political sentiment to legitimize authority or mobilize resistance, thereby influencing voter attitudes. However, artworks can also explore morally relevant topics without expressing a clear positive or negative evaluation.

Since both ethics and aesthetics deal with values, philosophers seek to clarify the relation between moral and aesthetic values, proposing diverse theories of their interaction. Ethicism asserts that the moral value of an artwork can increase its aesthetic value, while ethical defects may undermine its artistic merit. This view is reversed by immoralism, which suggests that in some cases, moral flaws enhance aesthetic experience. Autonomism rejects both positions, arguing that these domains of evaluation are independent.

Scientific approaches rooted in psychology and related fields employ empirical methods to conduct inquiries and justify hypotheses. The psychology of aesthetics examines the mental processes involved in the perception and appreciation of beauty and art, using methods such as experimentation, observation, and surveys.

Experimental aesthetics is an early and influential approach pioneered by Gustav Fechner. It follows a bottom-up methodology that starts with human sensation, investigating preferences to simple physical stimuli, such as basic colors and shapes. Gestalt psychology relies on a more holistic outlook, examining how composition and object placement influence aesthetic experience, like the relation between balanced organization and a sense of calm. Some works, such as Daniel Berlyne's approach, shift the focus from perception to emotion, suggesting that features like novelty and complexity cause arousal and that the right amount of arousal is pleasurable.

Psychological analysis also examines the temporal structure of aesthetic experiences of art. One outlook identifies two phases: an initial first impression in which the observer forms a rough general idea of the artwork's topic, structure, and meaning, followed by a focal analysis of more specific features. Research further explores how circumstances influence aesthetic experience, like the contrast between encountering a painting in a museum or a shopping mall. In addition to physical circumstances, social and personal factors also influence aesthetic experience, such as group dynamics, prior knowledge, and the motivation for seeking the experience.

Photo of a landscape with grass, trees, and a blue sky with clouds
Evolutionary psychology examines the evolutionary function of aesthetic sensitivities, like preferences for environments conducive to survival, such as landscapes resembling the African savannah.

Evolutionary psychology analyzes mental phenomena as products of natural selection. It asserts that genetic variations responsible for new capacities are passed on to future generations if they enhance survival and reproduction. Adopting this approach, evolutionary aesthetics interprets beauty and other aesthetic experiences as adaptive traits that serve diverse functions. Examples are aesthetic preferences for environments conducive to survival, such as landscapes resembling the African savannah, and sexual selection by identifying genetically fit mates. By focusing on the relatively permanent biological nature of humans, evolutionary psychology sees aesthetic values as universal or transcultural patterns of taste and appreciation, contrasting with theories in the philosophy of art that understand aesthetic values as cultural constructs.

Neuroaesthetics applies neuroscientific insights and methods to study the relation between brain activity and aesthetic experience. Aesthetic experiences arise from diverse brain processes responsible for organizing sensory stimuli, forming cognitive interpretations, and generating emotional responses. Neuroaesthetics examines these processes using various methods, including neuroimaging techniques like fMRI. In one type of experiment, participants view diverse artworks, some considered beautiful and others ugly. By comparing brain responses measured through neuroimaging, researchers can discern, for example, that the brain area known as the orbitofrontal cortex is more active when viewing beautiful paintings.

Cognitive science employs an interdisciplinary approach to study mental phenomena by examining how they access and transform information. An influential theory, suggested by Ernst Gombrich, analyzes aesthetic experience through the interplay of low-level and high-level information processes: human sensation provides low-level information, which is organized and interpreted using high-level conceptual background knowledge. Specific frameworks in cognitive science have also been used to analyze aesthetic phenomena. For instance, the modularity of mind—the hypothesis that the mind is composed of mental modules that function independently—has been employed to explain that paintings can represent real objects by triggering the same mental modules responsible for the recognition of real objects.

Comparative aesthetics

Comparative aesthetics examines diverse aesthetic traditions, analyzing the similarities and differences in their standards of beauty and theoretical approaches. For example, the focus in Western aesthetics on high art and its separation from everyday affairs is not common in most other traditions, for which art is typically closely integrated with practical functions in everyday life, including religion and moral education. Artistic differences between different traditions also encompass dominant media, common styles, and chosen motifs.

The comparison of cultural products from different traditions presents various conceptual challenges associated with tradition-specific aesthetic concepts and standards of evaluation. The uncritical application of standards from one tradition to evaluate the works of another can result in cultural imperialism. However, these differences also provide opportunities to artists and philosophers to incorporate new elements and explore novel perspectives.

Indian aesthetics draws a close connection between artistic activity and religious practice. It argues that artistic expression is a spiritual endeavor that should be informed by knowledge of the self and reality, express devotion to the divine, and avoid attachments to the fruits of the activity. Indian aesthetics analyzes art in terms of basic life emotions, called rasas, such as delight, humor, sadness, and anger. It sees art as a play that imitates reality by conveying experiences of the rasas. Its focus is on the universal expressions of human emotional life rather than person-specific feelings. This school of thought identifies artistic creativity as the ability to harness the full potential of the medium, like colors, sounds, and words, to convey experiential universals. For the audience, it recommends an aesthetic attitude characterized by a psychic distance from private concerns to transcend the personal self and become receptive to universal elements.

Painting of a hilly landscape together with poetry in the top right area
Chinese aesthetics places specific emphasis on poetry, painting, and calligraphy. They are known as the three perfections and are sometimes combined in a single artwork, as in Kun Can's Landscape after Night Rain Shower.

Chinese aesthetics emphasizes the spontaneous nature of artistic creativity and its connection to the moral and spiritual domains. It argues that art should foster harmony within society and align with the natural order of the universe. In this role, art is both self-expression and self-cultivation aimed to promote social well-being. The main focus of Chinese aesthetics is on poetry, painting, and calligraphy, known as the three perfections. This tradition influenced Japanese aesthetics, which is characterized by its interest in nature. Different art styles in this tradition are shaped by religious outlooks, particularly Shinto and Buddhism. Japanese theories of art stress the interrelation between the experience of the artist and the response of the audience.

Islamic philosophers see art as a means of communicating philosophical and religious truths, making them accessible to the general public without requiring abstract theoretical thought. Thinkers such as Al-Farabi and Avicenna argued that imagination rather than reasoning underlies artistic creation and appreciation. According to this view, art imitates reality and evokes emotions to convey underlying truths and positively influence behavior. Religious teachings play a central role in Islamic aesthetics. For example, the belief that Allah is transcendent and boundless has resulted in the avoidance of figurative depictions and the emphasis on abstract art forms.

African aesthetics emphasizes the intuitive and emotional nature of art, highlighting its communal function in social life. Early scholarship on this tradition was typically conducted from an ethnocentric perspective using Western aesthetic standards to interpret and evaluate African art. This usually resulted in the portrayal of African artworks as exotic curiosities that lack the sophistication of high art. The emergence of indigenous scholarship in the 20th century sought to correct this interpretation, arguing that the emphasis on moral, emotional, and intuitive aspects reflects different artistic standards rather than a deficiency. This school of thought, often associated with the concept of Négritude, focuses on the importance of feelings in contrast to abstraction and intellectual analysis.

Environment, everyday life, and religion

Environmental aesthetics deals with the appreciation of nature, including elements such as forests, mountain ranges, rivers, and flowers. It encompasses both transient appearances, such as the fleeting beauty of a landscape during sunset, and enduring aspects, such as the majesty of a centuries-old tree. This field focuses on sensory and formal qualities associated with beauty and related aesthetic qualities. It contrasts in this respect with the philosophy of art, which typically emphasizes the interpretation of underlying meanings associated with expression and representation. However, some approaches to environmental aesthetics also consider the impact of background knowledge on the aesthetic experience of nature. For instance, ecological awareness of the intricate relationships within an ecosystem can shape the appreciation of a woodland environment by understanding it as a habitat of diverse species.

Photo of a golden Buddha statue
Religious art serves specific religious functions, such as conveying moral teachings or aiding devotional practices.

In its broadest sense, environmental aesthetics encompasses the appreciation of any environment, including those created by humans. This inquiry is closely associated with everyday aesthetics, which examines aesthetic phenomena encountered in daily life. Everyday aesthetics covers both public and private environments, ranging from modern cities and industrial sites to private homes and backyards, as well as personal adornments and consumer products, such as clothing, hairstyles, industrial design, and web design. The aesthetics of popular art, a related discipline, investigates aesthetic qualities in popular culture and compares the evaluative standards of popular art with high or fine art. For example, it studies the contrast between commercial mass art and experimental avant-garde and explores specific types of popular art, such as kitsch.

Art plays a central role in the field of religion and manifests in many forms, including paintings, sculptures, architecture, music, dance, and literature. Its key characteristic comes from its religious function, such as conveying theological and moral teachings, representing symbolic truths, inspiring religious experiences, and aiding devotional practices. Religious art is part of all major religions and was the dominant art form during ancient and medieval times. However, its influence began to wane in the modern period due to secularization. This shift is also reflected in developments in the philosophy of art that introduced a focus on disinterestedness and the autonomy of aesthetic experience from external purposes, including religious goals.

Others

Various theories of aesthetics are associated with specific philosophical schools of thought. Marxist aesthetics examines the relation between art, class structure, and social ideology, exploring how art can enforce or challenge established power hierarchies. Feminist aesthetics criticizes male biases in aesthetic theory and artistic practice while exploring alternatives. It investigates unfair social institutions and aesthetic standards that disadvantage women and exclude them from the art world. An example is the male gaze—a cultural phenomenon that treats women as objects of male spectatorship rather than as artistic creators. Postmodern aesthetics is a diverse movement that challenges established concepts and theories in the field of aesthetics. It typically rejects the focus on disinterested pleasure, the autonomy of art from other domains, and the distinction between high and popular art. It tends to promote a pluralism that embraces diversity, playfulness, and irony.

Rendered geometric fractal of a black shape against a blue background
Computer art includes the generation of images using algorithms, such as the fractal geometry of the Mandelbrot set.

The term mathematical beauty refers to aesthetic qualities of abstract mathematical concepts and theories. For instance, a mathematical proof may be considered beautiful if it demonstrates a profound insight in an effective manner or reveals an underlying unity of seemingly disparate mathematical ideas.

Computer art involves the use of computers in the creation of artworks. It can take many forms, ranging from minor digital enhancements of existing artworks to entirely new creations generated using complex algorithms. Its abstract nature based on symbolic representation and manipulation of electronic signals distinguishes computer art from traditional forms of art, which rely on more tangible media. This medium offers new artistic possibilities, such as virtual reality and interactivity. Rapid developments in artificial intelligence in the 21st century have significantly impacted computer art. They include the emergence of generative models—systems that are trained on existing media to create new texts, images, music, or videos in response to verbal descriptions of the intended result. Examples include ChatGPT, Stable Diffusion, MuseNet, and RunwayML.

Meta-aesthetics examines the fundamental assumptions and concepts underlying aesthetics. It asks about the existence of aesthetic facts, the meaning of aesthetic statements, and the ways of acquiring aesthetic knowledge. A central meta-aesthetic debate between realism and anti-realism addresses whether there are mind-independent aesthetic facts. A related discussion between cognitivism and non-cognitivism considers whether aesthetic statements can be objectively true or primarily express personal emotions.

History

Ancient

Photo of a marble bust of a bearded man
Plato understood art as a craft that imitates reality.[158]

Aesthetics has its roots in ancient thought, which typically interpreted beauty as a metaphysical phenomenon associated with the order of the cosmos. In ancient Greek philosophy, early explorations of the nature of beauty are found in Pythagorean philosophy in the 5th and 4th centuries BCE. This tradition proposed that beauty arises from the proportion and harmony between different elements, an idea later also examined by the StoicsPlato (427–347 BCE) analyzed pure beauty as an immutable form that exists independent of matter. He argued that material entities are beautiful if they participate in the form of beauty. Plato understood art as a craft that seeks to imitate and represent material entities. He acknowledged that art has some didactic value but was overall critical of it, asserting that its derivative nature, based on imitation of sensible features, cannot lead to true knowledge.

Aristotle (384–322 BCE) examined aesthetics through the lens of poetry. He agreed with Plato's idea that art is a form of imitation but adopted a more positive outlook, proposing that it can reveal universal truths. Aristotle suggested that successful artistic imitation is pleasurable and can have therapeutic or cathartic effects. By linking this pleasure to beauty, he tried to explain why the imitation of unpleasurable phenomena, like tragic stories, can be enjoyable. Also influenced by Plato, Plotinus (204–270 CE) argued that beauty is not based on sensory symmetries or simple proportions but embodies an underlying order, harmony, and unity associated with the ultimate source of creation.

In ancient India, the Natya Shastra, traditionally attributed to Bharata (c. 200 BCE–200 CE), formulated the rasa theory of art. This theory posits that the goal of art is to convey fundamental life emotions as experiential universals of human existence. In ancient China, the philosophy of art was shaped by Confucianism. It emphasized self-cultivation and the relation between nature and human culture.

Medieval

During the medieval period, the rise of Christianity led Western aesthetic thinkers to blend ancient Greek thought with religious teachings, often in the form of philosophical theology. Influenced by Plato and Plotinus, Augustine of Hippo (354–430 CE) explored the distinction between artistic creation, which transforms matter, and divine creation, which brings forth existence out of nothing. He thought that all beauty originates from God and analyzed it in terms of unity, equality, number, proportion, and order. Thomas Aquinas defined beauty as what brings pleasure upon perception. For him, the mind plays a central role in this process since beauty lies in the immaterial form of the perceived object that the mind recognizes in the sensory data. Aquinas saw beauty as a basic category of being and identified it with proportion, radiance, and integrity.

Black-and-white image of an elderly man with a long beard wearing a robe
Al-Farabi saw beauty as a divine attribute of Allah.

An integration of Greek philosophy and religious thought also happened in the Islamic world. Al-Farabi (c. 878–950 CE) associated beauty with pleasure and saw it as a degree of perfection and a divine attribute of Allah. Avicenna (980–1037 CE) distinguished sensible from intelligible beauty and explored psychological processes underlying aesthetic judgments, such as the role of imagination.

Meanwhile in India, the rasa theory of art expanded to also encompass devotional practices, including efforts to portray or evoke profound religious experiences of the union with the divine. For example, Abhinavagupta (c. 950–1025 CE) elaborated the spiritual dimension of the rasa theory, drawing a sharp distinction between ordinary worldly emotions and rasas as transcendent aesthetic emotions.

In Chinese thought, Xie He (c. 5th to 6th centuries CE) combined Daoist and Confucian ideas, suggesting that artists align with the natural order of the universe and spontaneously express the movement of life in their artworks. He also proposed a set of basic principles of painting. Guo Xi (c. 1020–1090 CE) argued that artworks reflect the moral character and spiritual outlook of the artist, which he saw as a central factor of the artwork's aesthetic value. During this period, the growing influence of Buddhism on Chinese aesthetic thought led to an artistic shift from objective reality to subjective experiences as a result of Buddhist teachings on the illusory nature of reality.

The medieval period in the West came to an end with the emergence of the Renaissance starting in the 15th century. This change led to the revival of classical aesthetic ideals while secularization paved the way for rationalist inquiries into general laws of beauty and empiricist analyses of sensory and emotional experiences in the subsequent Age of Enlightenment.

Modern and contemporary

Oil painting showing David Hume from the front against a dark background, dressed in a red coat with gold embroidery, his left arm resting on a surface
David Hume understood beauty as a pleasurable sentiment and explored taste as the inner sense responsible for this sentiment.

Modern aesthetics emerged in the 18th century as philosophers systematically engaged with its foundational concepts while carefully formulating and critiquing major positions. A key step in this process happened through the philosophy of Alexander Baumgarten (1714–1762), who first conceived aesthetics as a distinct field of inquiry: the science of sensory cognitions or the study of what is sensed and imagined. In British philosophy, Francis Hutcheson (1694–1746) followed ideas of the third Earl of Shaftesbury (1671–1713) and provided an early theory of taste, conceptualizing it as an inner sense responsible for aesthetic apprehension. This outlook inspired David Hume (1711–1776) to develop a subjective theory of beauty, understanding it as a pleasurable sentiment caused by perceptions. He integrated this perspective with the existence of intersubjective standards of beauty as principles of taste governing which objects are experienced as beautiful.

Immanuel Kant (1724–1804) expanded Hume's idea that aesthetic judgments are both subjective and universally valid, arguing that the underlying pleasure must be disinterested to follow universal standards. According to Kant, this type of pleasure comes from a free play in which the mental faculties of imagination and understanding harmoniously interact. In response to earlier theories by Edmund Burke (1729–1797), Kant also examined the sublime as a distinct aesthetic quality.

Kant's thought inspired diverse developments in German philosophy. Friedrich Schiller (1759–1805) saw art as a unifying phenomenon that synthesizes different basic human drives in a type of play. F. W. J. von Schelling (1775–1854) shared a similar perspective, arguing that art reconciles opposites and reveals the underlying unity of the self and nature. G. W. F. Hegel (1770–1831) explored aesthetics through his philosophical system of absolute idealism, seeing artistic beauty as the sensory manifestation of ideas. He analyzed art history from antiquity to his present day as a series of progressive stages of this manifestation.

Combining Kantian and Indian philosophy, Arthur Schopenhauer (1788–1860) saw disinterested aesthetic experience as a suspension of the will, resulting in a temporary peace of mind by interrupting the cycle of striving and suffering. He inspired the Chinese philosopher Wang Guowei (1877–1927), who integrated Schopenhauer's ideas with Buddhist thought. Wang viewed the goal of art as the creation of worlds within the world, which are open to disinterested reflection. Friedrich Nietzsche (1844–1900) rejected the disinterestedness of aesthetic experience and the autonomy of art from other domains. Instead, he considered art an expression of the struggle between opposing life forces and saw art as a vehicle of transformation and life affirmation.

Following the thought of Karl Marx (1818–1883), Marxist aesthetic philosophers like Leon Trotsky (1879–1940) and Georg Lukács (1885–1971) examined how art reflects and shapes social ideologies and power hierarchies. Drawing from Marxist ideas, Theodor Adorno (1903–1969) critiqued the commodification of art and explored its ability to express alienation and challenge societal norms. Also adopting a Marxist perspective, Walter Benjamin (1892–1940) studied how advances in technological reproducibility transform art.

Romanticist thought, expressed in the works of J. W. von Goethe (1749–1832), William Wordsworth (1770–1850), and Samuel Taylor Coleridge (1772–1834), emphasized artistic originality, creativity, and the expression of profound feelings. It saw artworks as products of human genius that defy rule-based understanding. This school of thought inspired the theory of expressionism, which asserts that the primary function of art is to communicate emotions and other mental states. It was explored by thinkers such as Leo Tolstoy (1828–1910), Benedetto Croce (1866–1952), and R. G. Collingwood (1889–1943). Intentionalism, a closely related position, focuses on the author's intent as the source of meaning of artworks. Monroe Beardsley (1915–1985) opposed this view, arguing that meaning is not fixed by the author's intent. Sigmund Freud (1856–1939) and Carl Jung (1875–1961) interpreted art through a psychoanalytic perspective as expressions of the unconscious, an approach also later explored by Richard Wollheim (1923–2005).

In the late 19th and early 20th centuries, aestheticism became a prominent view in English-speaking philosophy. For example, Walter Pater (1839–1894) and Oscar Wilde (1854–1900) proposed that art is an end in itself without an ulterior purpose. Pragmatists rejected this outlook and the idea that aesthetic experience is disinterested. For instance, John Dewey (1859–1952) proposed that the value of art lies in the unique experiences it provides, which can lead to individual and societal improvements. Formalism became another influential theory of art in the early 20th century. It dismisses the focus on expressive and representational aspects and argues instead that artworks are defined by formal features, like the arrangement of perceptual qualities. Clive Bell (1881–1964), a major proponent of this view, termed this arrangement "significant form".

Black-and-white photo of a man wearing a suit and a tie
Martin Heidegger proposed that artworks can reveal truths about human existence and provide new perspectives of understanding.

The emergence of Dadaism and conceptual art challenged traditional definitions of art based on intrinsic features of artworks. As a result, anti-essentialism, which understands art as a social construct without an inherent essence, gained prominence in the second half of the 20th century, exemplified in the theories of Frank Sibley (1923–1996) and Nelson Goodman (1906–1998). These developments inspired Arthur C. Danto (1924–2013) and George Dickie (1926–2020) to propose institutional definitions, arguing that social conventions set by the art world determine which objects are artworks. Mary Mothersill (1923–2008) challenged these developments. She aimed to restore earlier conceptions of beauty associated with Aquinas, Hume, and Kant, focusing on the apprehension of aesthetic qualities.

In continental philosophy, the school of phenomenology explored diverse aspects of the immediate experience of art. For example, it examined how artworks can depict unreal objects, how imagination is involved in the process, and how art can reveal features of reality. This tradition is closely related to existentialist aesthetics, which views artworks as expressions of human freedom that can authentically portray central aspects of the human condition. The philosophy of Martin Heidegger (1889–1976) influenced both traditions. He criticized the focus on disinterested pleasure found in modern philosophy of art, arguing that artworks can reveal truths about human existence and provide new perspectives of understanding. Heidegger's student Hans-Georg Gadamer (1900–2002) further explored the relation between art and truth, examining aesthetic experience and traditional theories through phenomenological analysis and hermeneutic interpretation.

Postmodern thinkers, like Roland Barthes (1915–1980) and Jacques Derrida (1930–2004), challenged the separation of art from everyday life and the idea that artworks have a stable meaning or universal value. They suggested instead that artistic merit depends on historical and cultural contexts. Starting in the 1970s, feminist perspectives in aesthetics challenged male-centric theories and practices within aesthetic philosophy and the art world. For example, Simone de Beauvoir (1908–1986) and Luce Irigaray (1930–present) explored how feminine perspectives are marginalized by masculine standards.

Ethical egoism

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Ethical_egoism In ethical philosophy...