In China, beginning roughly in the 9th century, Neo-Confucianism maintained that reality has a rational order expressed in the principle Li, which acts as a ground of being. In ancient Greek philosophy starting in the 6th century BCE, the pre-Socratics discussed the first principles from which all things arise. The school of Vaisheshika arose roughly in the 2nd century BCE and developed a system of six fundamental categories of being. Various historiographical debates address the question of whether a truly objective account of the past is possible.

Levels of reality

It characterizes realism as the view that the truth or meaning of sentences is determined by external standards or mind-independent reality. A semantic approach to the debate between realism and anti-realism, proposed by Michael Dummett, argues that the underlying disagreement concerns the meaning of statements rather than the existence of entities. On this view, reality is made up of countless concrete worlds existing in parallel without interacting with one another. In the social sciences, critical realism holds that observable events in the social world only partially disclose reality. Local realism is a view that combines the principle of locality with the notion that there are definite physical properties, whether or not they are being observed by someone.

Related concepts

Inspired by Leibniz, David Lewis (1941–2001) developed modal realism, maintaining that possible worlds are as real as the actual world. E. Moore (1873–1958) drew on common sense and empirical science to oppose idealism, emphasizing that the world exists independently of the mind. Responding to Kant’s philosophy, the German idealists sought a unifying principle as the foundation of all reality. In Hindu philosophy, the school of Advaita Vedanta emerged in the 8th century and held that the world of everyday appearances is an illusion, contrasting it with the ultimate reality of Brahman. Inspired by Plato’s realm of forms, Plotinus (c. 204 – c. 270 CE) identified the One as the supreme principle underlying all of reality. His student Aristotle (384–322 BCE) proposed a system of ten categories describing the fundamental constituents of reality.

Levels of reality

In a broad sense, appearances are not limited to what people perceive but can also include memories, beliefs, and thoughts. Unreal entities, by contrast, depend for their existence on thoughts and ideas; they would not arise or would vanish without the mental activity creating or sustaining them. A related topic concerns the possibility and limits of knowledge as a successful cognitive contact with reality. Anti-realism, by contrast, holds that certain aspects of reality depend on mental processes, subjective perspectives, or social https://www.zumospin.net/ conventions.

• The structure of reality concerns the fundamental patterns of being, describing how entities are organized and interact with each other.
• One perspective holds that such objects are illusory or unreal because they lack existence in the physical world outside the simulation.
• For example, if a planet or a virus is real then it exists on its own and behaves according to its nature, even if people are unaware or hold false beliefs about it.
• Criteria of reality are proposed features or standards that distinguish real entities from unreal ones.
• Plato (c. 427 – c. 347 BCE) argued for the existence of a realm of eternal forms or ideas in addition to the material world of mutable entities.
• Anti-realism about abstract objects in mathematics takes various forms, including, but not limited to, fictionalism.
• There are different ways to conceptualize the relation between fundamental and non-fundamental entities, including the ideas of ontological dependence, metaphysical grounding, reduction, supervenience, and emergence.

As individual entities, they contrast with universals, which are general, repeatable entities that can have many instances, such as the color blue, the shape roundness, and the property of being a mammal. Various categories of being or constituents of reality are discussed in the academic discourse. Similarly, the many-worlds interpretation of quantum physics suggests that in quantum measurements, not only one but all possible outcomes occur, interpreted as a branching of the universe into multiple worlds. It is often contrasted with essence, which denotes the nature or characteristic features of an entity.
More general constraints arise from limits of human cognitive faculties rather than situation-specific circumstances, such as facts too complex for anyone to conceive. Testimony is a transmission of knowledge from one person to another through communication.k Memory is the capacity to store information from other sources and make it available to cognitive processes when needed. Reason is the ability to draw logical inferences and arrive at truths independent of immediate sensory input. Anti-realism is understood as a view that identifies the meaning of a statement with the evidence that would support it or the conditions under which a person is justified in asserting it. It opposes the idea that world and mind are essentially correlated, emphasizing the mind-independent nature of reality beyond the way humans perceive and think about it.
Skepticism about metaphysics holds that it is not possible to know the fundamental nature of reality, such as claims about categories of being or the existence of universals. It holds that the scientific view of the world is either exactly or at least approximately true by presenting reality as it is. For example, emotivism holds that value statements express emotional attitudes of subjective approval or disapproval rather than objective facts. Anti-realist views reject the mind-independent existence of values and can take various forms. Realists hold that values are objective features of reality, meaning that there are mind-independent facts about whether something is good or bad, irrespective of subjective beliefs or personal preferences.

Realism and anti-realism

This view emphasizes that reality is encountered, rather than invented, and can resist or frustrate beliefs and desires, unlike malleable imaginary creations. Another influential proposal treats mind-independence as a criterion of reality, arguing that real entities do not depend on how people think about them. The Eleatic principle is controversial because it is typically taken to deny that abstract objects studied in fields like mathematics, such as numbers, are real. However, stories about Santa Claus, such as written texts in children’s books, are part of reality since they can influence how people think. Discussed in ancient Greek philosophy as the Eleatic principle, it states that to be real is to be able to produce changes and to be affected by them. Criteria of reality are proposed features or standards that distinguish real entities from unreal ones.

• Other suggested criteria identify reality with what is observable, measurable,a coherent,b useful, objective, intersubjective, or fundamental.
• Although it is not a widely accepted position, various thought experiments undermining the reliability of human cognitive faculties are discussed in the academic literature.
• Relativism, another form of anti-realism, holds that what counts as real varies based on one’s perspective or conceptual framework.
• For example, psychologism asserts that mathematical objects are mental constructions or ideas rather than abstract objects.
• According to a common view, concrete objects exist in space and time, such as a flower, a horse, and a ship.
• The term reality overlaps with various related concepts, such as being, existence, world, actuality, and truth.
• On this view, reality is made up of countless concrete worlds existing in parallel without interacting with one another.

Anti-realism rejects this view, arguing instead that there is no external world or that reality depends in certain respects on mental processes, subjective perspectives, or social conventions. Realism and anti-realism are families of views concerning the mind-independence of reality. Some interpretations of quantum mechanics hold that measurement outcomes are inherently probabilistic, thereby rejecting causal determinism, but this is not true for all interpretations.g According to this view, what happened in the past fixes what will happen in the future, including human behavior. Causal determinism is the view that every event is fully determined or necessitated by prior events. Laws of nature play a central role in the physical sciences by providing frameworks for predicting outcomes under specified conditions.

Levels of reality

Accordingly, worldviews address not only theoretical matters but also practical and evaluative outlooks about what matters and how one should act. Another view maintains that they are real as digital objects with genuine existence and causal powers, residing within and being constituted by computational processes. Similarly, virtual reality worlds may incorporate real-world objects into the simulation or be entirely virtual.l Although it is not a widely accepted position, various thought experiments undermining the reliability of human cognitive faculties are discussed in the academic literature. It denies the existence of knowledge in any form or domain, arguing that knowledge is impossible. These limitations indicate a gap whereby reality is not fully captured and exceeds knowledge.

Values

Anti-realism about abstract objects in mathematics takes various forms, including, but not limited to, fictionalism. Anti-realists hold that there are no abstract objects and offer alternative explanations. Realists and anti-realists about abstract objects debate whether, or in what sense, such entities form part of reality. Nominalism, another anti-realist view, rejects both mental and non-mental interpretations of universals. For example, a person may be a realist about universals and an anti-realist about values. In this sense, realism and anti-realism encompass many domain-specific positions across diverse fields.
For example, the laws of thermodynamics describe how heat and other forms of energy behave, such as the idea that the total amount of energy is always conserved. Existence monism contrasts with existence pluralism, which aligns more closely with everyday experience by asserting that reality is made up of many objects. There are different ways to conceptualize the relation between fundamental and non-fundamental entities, including the ideas of ontological dependence, metaphysical grounding, reduction, supervenience, and emergence. Another structural feature concerns the idea that some entities depend on, or are grounded in, other entities.
On this view, unobservable entities may be invoked in theory construction to aid prediction but should not be taken to exist. Scientific realism is the view that the best scientific theories provide an accurate description of a mind-independent world. Error theory asserts that all value statements are false because there are no values.i Another form of anti-realism maintains that value statements are neither true nor false but meaningless. According to subjectivism, values depend on the attitudes and preferences of individuals. Non-naturalism, another form of realism, maintains that values differ significantly from empirical properties and belong to another domain of reality.