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.

• Inspired by Plato’s realm of forms, Plotinus (c. 204 – c. 270 CE) identified the One as the supreme principle underlying all 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 is often contrasted with essence, which denotes the nature or characteristic features of an entity.
• Nominalism, another anti-realist view, rejects both mental and non-mental interpretations of universals.
• Accordingly, worldviews address not only theoretical matters but also practical and evaluative outlooks about what matters and how one should act.
• 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.
• Debates between realists and anti-realists span multiple domains, addressing the objective existence of universals, abstract objects, values, and unobservable entities posited by scientific theories.

Related concepts

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. For example, value theory is concerned with the reality of values, and the philosophy of mathematics explores in what sense mathematical objects, like numbers and sets, form part of reality. Different worldviews offer distinct answers to existential questions about meaning, morality, and the nature of reality, such as the contrast between religious and secular worldviews. A worldview is a comprehensive framework for understanding reality and humanity’s place within it. One perspective holds that such objects are illusory or unreal because they lack existence in the physical world outside the simulation. The reality–virtuality continuum is a theoretical framework that posits a continuous scale of mixed reality forms. 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. According to a common view, concrete objects exist in space and time, such as a flower, a horse, and a ship. Events are proposed constituents of reality that occur in time, such as the discovery of penicillin and the Second World War.

Related concepts

• Anti-realism, by contrast, holds that certain aspects of reality depend on mental processes, subjective perspectives, or social conventions.
• By contrast, Arthur Schopenhauer (1788–1860) criticized German idealism and held that a blind, irrational will is the underlying principle of reality.
• For example, one view suggests that macroscopic objects, such as a chair, depend on the microscopic objects that underlie them, such as elementary particles.
• Computer scientists discuss how systems of knowledge representation can organize information about reality and make it accessible to computational processes.
• Events are proposed constituents of reality that occur in time, such as the discovery of penicillin and the Second World War.

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

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, https://www.zumospin.net/ 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. 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. 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. Monism and pluralism are families of views about the roles of unity and multiplicity in the structure of reality. According to this view, even a complete understanding of physics would not render sciences dedicated to higher levels, such as psychology, obsolete. Non-reductive physicalists hold that everything is ultimately physical while insisting that higher-level psychological facts cannot be reduced to fundamental physics. In this sense, there can be matter without biological life, whereas life is built upon matter and depends on it. Lower levels, by contrast, operate according to more basic mechanisms and are prior to the higher ones.

Related concepts

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. 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.

Realism and anti-realism

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. Moral skepticism is the view that there is no moral knowledge, for instance, that one cannot know whether a given behavior is morally right or wrong. Some forms target specific domains of knowledge, such as religious skepticism, which denies that beliefs about God or other religious doctrines amount to knowledge. Philosophers examine various limitations of knowledge or obstacles to the cognitive contact with reality. Philosophers discuss various sources of knowledge as ways of how this cognitive contact is established, including perception, introspection, reason, memory, and testimony. 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. 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. 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.