It is often contrasted with essence, which denotes the nature or characteristic features of an entity. 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.
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. In this sense, it is the state of being real or what all real entities have in common, separating them from unreal or illusory ones. In a slightly different sense, reality is not the totality itself but an aspect shared by all its constituents. Theories of the nature of reality have been discussed since antiquity and continue to shape contemporary inquiry, with influential early traditions originating in ancient Indian, Chinese, and Greek thought. Contemporary technology in the form of augmented and virtual reality can inform experience and raises questions about the ontological status of virtual objects.
Another structural feature concerns the idea that some entities depend on, or are grounded in, other entities. 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. Various categories of being or constituents of reality are discussed in the academic discourse.
Realism and anti-realism
An even wider definition includes everything that has existed, exists, or will exist. This time, The Traitors is bringing in ordinary people, a whole new group of players who seem more… The longtime judge discussed his… Netflix is bringing a new dating series to its lineup with Weight To Date, which will follow people navigating love… On the review aggregator website Rotten Tomatoes, 93% of 92 critics’ reviews are positive, with an average rating of 8/10.
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. For example, psychologism asserts that mathematical objects are mental constructions or ideas rather than abstract objects. It holds that this practice can be useful in some contexts without ascribing substantive or framework-independent reality to such entities. According to conceptualism, universals exist in the mind as concepts through which people categorize and order their impressions, acting as tools of cognitive organization rather than properties of external entities. Platonism about universals holds that they are part of reality in their own right, independent of the particular entities that instantiate them.
Related concepts
Inspired by Leibniz, David Lewis (1941–2001) developed modal realism, maintaining that possible worlds are as real as the actual world. Responding to Kant’s philosophy, the German idealists sought a unifying principle as the foundation of all reality. 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. In ancient Greek philosophy starting in the 6th century BCE, the pre-Socratics discussed the first principles from which all things arise. In psychoanalytic theory, the reality principle is a proposed mechanism that counteracts the pleasure principle, delaying immediate gratification when it collides with the demands of external reality.
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. For example, one view suggests that macroscopic objects, such as a chair, depend on the microscopic objects that underlie them, such as elementary particles. The structure of reality concerns the fundamental patterns of being, describing how entities are organized and interact with each other.
- Criteria of reality are proposed features or standards that distinguish real entities from unreal ones.
- 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.
- In a broad sense, appearances are not limited to what people perceive but can also include memories, beliefs, and thoughts.
- While some skeptical scenarios use the idea of a simulated reality to challenge the reliability of human cognition, contemporary technologies such as augmented reality and virtual reality can also inform experience.
- 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.
- 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.
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.
The reality–virtuality continuum is a theoretical framework that posits a continuous scale of mixed reality forms. 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.
- On this view, higher levels show greater complexity and new phenomena but depend on the lower ones and could not exist without them.
- Lower levels, by contrast, operate according to more basic mechanisms and are prior to the higher ones.
- Anti-realism, by contrast, holds that certain aspects of reality depend on mental processes, subjective perspectives, or social conventions.
- 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.
- E. Moore (1873–1958) drew on common sense and empirical science to oppose idealism, emphasizing that the world exists independently of the mind.
- The simulation hypothesis is the view that the whole world and everything within it is a simulated reality, including humans.
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. In the broadest sense, being is the most general category that applies to everything and contrasts only with mister golden nothingness.