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 conventions.
- Mereological universalism holds that any collection of entities constitutes a whole, even if the entities are otherwise unrelated.
- These limitations indicate a gap whereby reality is not fully captured and exceeds knowledge.
- His student Aristotle (384–322 BCE) proposed a system of ten categories describing the fundamental constituents of reality.
- However, stories about Santa Claus, such as written texts in children’s books, are part of reality since they can influence how people think.
- For example, emotivism holds that value statements express emotional attitudes of subjective approval or disapproval rather than objective facts.
- The concept of reality overlaps with notions such as being, existence, world, actuality, and truth.
It overlaps with the cognitive sciences, which investigate how cognitive processes transform information about the world, and with neuroscience, which studies the brain activities underlying such processes. It concerns the question of how mental and linguistic entities, such as thoughts and words, can establish contact with reality by successfully referring to things in the world. It focuses on how individuals experience reality and how conscious states are intentional or directed towards entities other than themselves. Epistemology, another philosophical subdiscipline, explores how people can know reality. They examine what it means for something to be real, how entities are divided into different categories of being, and which entities exist at the most fundamental level.
Related concepts
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.
Values
- It comprises beliefs, ideas, and attitudes that form a background against which people interpret experiences, make decisions, and navigate life.
- Formalism, another form of anti-realism, understands mathematics as a practice of symbol manipulation, suggesting that mathematical truth is grounded in whether the manipulation rules permit the construction of a proof.
- Some outlooks suggest that only the fundamental level is ultimately real, arguing that non-fundamental entities are in some sense eliminable since reality can be described without them.
- Scientific realism is the view that the best scientific theories provide an accurate description of a mind-independent world.
- Immanuel Kant (1724–1804) rejected the possibility of objective knowledge of the things in themselves, arguing instead that all experience is shaped by the innate structures of human cognition.
- Testimony is a transmission of knowledge from one person to another through communication.k
- In a slightly different sense, reality is not the totality itself but an aspect shared by all its constituents.
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 https://www.zumospin.net/ 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.
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.
A central topic in ontology is the categories of being—fundamental classes that map out a comprehensive inventory of reality. Becoming, by contrast, covers change, like when an entity shifts from one state of being to another. Other suggested criteria identify reality with what is observable, measurable,a coherent,b useful, objective, intersubjective, or fundamental. It focuses on how things seem to be, distinguishing real appearances, which are as they seem, from illusory ones, which are not as they seem.
Related concepts
Mereological universalism holds that any collection of entities constitutes a whole, even if the entities are otherwise unrelated. Various theories of the mereological principles underlying composition have been proposed. For example, David Lewis’s modal realism asserts that there exist countless spatiotemporally unified possible worlds, each just as real as the actual world. A different view suggests that reality is made up of many worlds that exist in parallel to one another, each representing a distinct way of how things could have been. In a narrow sense, being contrasts with becoming, and denotes stable or permanent aspects of reality. Some philosophers, such as Alexius Meinong, hold that being is a broader concept than reality, encompassing nonexistent objects, such as merely possible or incomplete objects, in addition to real or actual ones.
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.
Some doctrines hold that God constitutes the most fundamental level of reality as the divine origin of all creation. One strand of the field analyzes culture-specific worldviews and compares them across societies. The simulation hypothesis is the view that the whole world and everything within it is a simulated reality, including humans. Computer scientists discuss how systems of knowledge representation can organize information about reality and make it accessible to computational processes. Reality testing is another suggested psychological function in which individuals distinguish intrapsychic from external events to assess how their experience aligns with reality.
Levels of reality
It comprises beliefs, ideas, and attitudes that form a background against which people interpret experiences, make decisions, and navigate life. By contrast, Arthur Schopenhauer (1788–1860) criticized German idealism and held that a blind, irrational will is the underlying principle of reality. Immanuel Kant (1724–1804) rejected the possibility of objective knowledge of the things in themselves, arguing instead that all experience is shaped by the innate structures of human cognition. 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.
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.
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.
Values
It holds that the debate is not based on a substantive disagreement but arises instead from conceptual confusions. For example, metaphysical idealism asserts that everything is essentially mental, for instance, by understanding material objects as ideas in the mind. In this sense, reality does not depend on human knowledge or consciousness and exists apart from them, including the aspects that no one is aware of. The widely accepted Big Bang theory holds that the universe began about 13.8 billion years ago, initially in an extremely hot, dense state, expanding and cooling ever since.
Naturalism argues that values are part of the natural world and can be studied by the natural sciences through empirical observation. Some positions concern the existence of values in general, while others are limited to specific domains, such as moral, aesthetic, or religious values. Formalism, another form of anti-realism, understands mathematics as a practice of symbol manipulation, suggesting that mathematical truth is grounded in whether the manipulation rules permit the construction of a proof. According to conventionalism, the truth of mathematical statements rests on linguistic conventions or definitions, rather than on their relation to language-independent reality.

