Reality is the sum or aggregate of all that is real or existent, as opposed to that which is merely imaginary. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of the universe, known and unknown. Philosophical questions about the nature of reality or existence or being are considered under the rubric of ontology, which is a major branch of metaphysics in the Western philosophical tradition. Ontological questions also feature in diverse branches of philosophy, including the philosophy of science, philosophy of religion, philosophy of mathematics, and philosophical logic. These include questions about whether only physical objects are real, whether reality is fundamentally immaterial, whether hypothetical unobservable entities posited by scientific theories exist, whether God exists, whether numbers and other abstract objects exist, and whether possible worlds exist.
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics, and purports to provide a viewpoint of the nature and methodology of mathematics, and to understand the place of mathematics in people's lives. The logical and structural nature of mathematics itself makes this study both broad and unique among its philosophical counterparts.
Moral realism is the position that ethical sentences express propositions that refer to objective features of the world, some of which may be true to the extent that they report those features accurately. This makes moral realism a non-nihilist form of ethical cognitivism with an ontological orientation, standing in opposition to all forms of moral anti-realism and moral skepticism, including ethical subjectivism, error theory ; and non-cognitivism. Within moral realism, the two main subdivisions are ethical naturalism and ethical non-naturalism.
Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted.
Coherentism is the name given to a few philosophical theories in modern epistemology.
Modal logic is a type of formal logic primarily developed in the 1960s that extends classical propositional and predicate logic to include operators expressing modality. A modal—a word that expresses a modality—qualifies a statement. For example, the statement "John is happy" might be qualified by saying that John is usually happy, in which case the term "usually" is functioning as a modal. The traditional alethic modalities, or modalities of truth, include possibility, necessity, and impossibility. Other modalities that have been formalized in modal logic include temporal modalities, or modalities of time, deontic modalities, epistemic modalities, or modalities of knowledge and doxastic modalities, or modalities of belief.
The is–ought problem, as articulated by the Scottish philosopher and historian David Hume (1711–76), states that many writers make claims about what ought to be, based on statements about what is. Hume found that there seems to be a significant difference between positive statements and prescriptive or normative statements, and that it is not obvious how one can coherently move from descriptive statements to prescriptive ones. The is–ought problem is also known as Hume's law, Hume's guillotine or fact–value gap.
"Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951. According to City University of New York professor of philosophy Peter Godfrey-Smith, this "paper [is] sometimes regarded as the most important in all of twentieth-century philosophy". The paper is an attack on two central aspects of the logical positivists' philosophy. One is the analytic–synthetic distinction between analytic truths and synthetic truths, explained by Quine as truths grounded only in meanings and independent of facts, and truths grounded in facts. The other is reductionism, the theory that each meaningful statement gets its meaning from some logical construction of terms that refers exclusively to immediate experience.
"Is Logic Empirical?" is the title of two articles that discuss the idea that the algebraic properties of logic may, or should, be empirically determined; in particular, they deal with the question of whether empirical facts about quantum phenomena may provide grounds for revising classical logic as a consistent logical rendering of reality. The replacement derives from the work of Garrett Birkhoff and John von Neumann on quantum logic. In their work, they showed that the outcomes of quantum measurements can be represented as binary propositions and that these quantum mechanical propositions can be combined in much the same way as propositions in classical logic. However, the algebraic properties of this structure are somewhat different from those of classical propositional logic in that the principle of distributivity fails.
Bastiaan Cornelis van Fraassen is a Dutch-American philosopher. He is a Distinguished Professor of Philosophy at San Francisco State University and the McCosh Professor of Philosophy Emeritus at Princeton University, noted for his seminal contributions to philosophy of science.
Quasi-realism is the meta-ethical view which claims that:
- Ethical sentences do not express propositions.
- Instead, ethical sentences project emotional attitudes as though they were real properties.
Language, Truth, and Logic is a 1936 work of philosophy by Alfred Jules Ayer. It brought some of the ideas of the Vienna Circle and the logical empiricists to the attention of the English-speaking world.
Speculative realism is a movement in contemporary Continental-inspired philosophy that defines itself loosely in its stance of metaphysical realism against the dominant forms of post-Kantian philosophy.
Following the developments in formal logic with symbolic logic in the late nineteenth century and mathematical logic in the twentieth, topics traditionally treated by logic not being part of formal logic have tended to be termed either philosophy of logic or philosophical logic if no longer simply logic.
The Pinocchio paradox arises when Pinocchio says "My nose grows now" and is a version of the liar paradox. The liar paradox is defined in philosophy and logic as the statement "This sentence is false." Any attempts to assign a classical binary truth value to this statement lead to a contradiction, or paradox. This occurs because if the statement "This sentence is false" is true, then it is false; this would mean that it is technically true, but also that it is false, and so on without end. Although the Pinocchio paradox belongs to the liar paradox tradition, it is a special case because it has no semantic predicates, as for example "My sentence is false" does.
Realism, Realistic, or Realists may refer to:
