Get it on Google Play
New! Download Unionpedia on your Android™ device!
Faster access than browser!


Index Logic

Logic (from the logikḗ), originally meaning "the word" or "what is spoken", but coming to mean "thought" or "reason", is a subject concerned with the most general laws of truth, and is now generally held to consist of the systematic study of the form of valid inference. [1]

289 relations: A Greek–English Lexicon, Abductive reasoning, ACM Computing Classification System, Alan Turing, Alfred North Whitehead, Alfred Tarski, Ammonius Saccas, An Essay Concerning Human Understanding, Analytic philosophy, Annals of Mathematics, Anti-realism, Antoine Arnauld, Anviksiki, Arend Heyting, Argument, Argumentation theory, Aristotle, Arithmetic, Arithmetic logic unit, Arthur Prior, Artificial intelligence, Atomic sentence, Augustus De Morgan, Automated theorem proving, Avicenna, Axiom, Axiom of choice, Barber paradox, Barry Smith (academic), Begriffsschrift, Bertrand Russell, Boethius, Boolean algebra, Cambridge University Press, Cantor's theorem, Charles Babbage, Charles Sanders Peirce, Christian, Church–Turing thesis, Clarence Irving Lewis, Classical logic, Completeness (logic), Complexity class, Computability theory, Computational linguistics, Computer science, Consequent, Consistency, Continuum hypothesis, Cooperative principle, ..., Critical thinking, Curry–Howard correspondence, David Hilbert, De Interpretatione, Decision tree, Deductive reasoning, Default logic, Defeasible reasoning, Deontic logic, Description logic, Dialectic, Dialectical logic, Dialetheism, Digital electronics, Domain of discourse, Dov Gabbay, Dynamic logic (modal logic), Edward N. Zalta, Elliott Mendelson, Encyclopædia Britannica, Entscheidungsproblem, Epistemic modal logic, Epistemology, Erasmus Montanus, Euclid, Europe, Fallacy, First-order logic, Formal methods, Formal system, Formula, Foundations of mathematics, Free logic, Friedrich Nietzsche, Fuzzy logic, Game semantics, Garrett Birkhoff, Gödel's completeness theorem, Gödel's incompleteness theorems, General relativity, Geometry, Georg Cantor, Georg Wilhelm Friedrich Hegel, George Boole, George Boolos, Gerhard Gentzen, Gongsun Long, Gottfried Wilhelm Leibniz, Gottlob Frege, Graham Priest, Graph theory, György Lukács, Han Feizi, Harvard University Press, High Middle Ages, Hilary Putnam, Hilbert's program, Hoare logic, Horn clause, Human, All Too Human, Hypothetical syllogism, If and only if, Immanuel Kant, Indian logic, Individual, Inductive reasoning, Inference, Infinitary logic, Informal logic, Intuitionism, Intuitionistic logic, Is Logic Empirical?, Jan Łukasiewicz, Józef Maria Bocheński, Jürgen Habermas, John Locke, John von Neumann, Jon Barwise, Joseph Goguen, Karl Marx, Knowledge representation and reasoning, Kripke semantics, Kurt Gödel, L. E. J. Brouwer, Large cardinal, Law, Law of excluded middle, Law of noncontradiction, Lewis Carroll, Linguistic modality, Linguistics, List of logic journals, List of logic symbols, List of logicians, Lists of mathematics topics, Logic gate, Logic in China, Logic programming, Logic puzzle, Logica Universalis, Logical biconditional, Logical conjunction, Logical connective, Logical consequence, Logical disjunction, Logical form, Logical truth, Logicism, Logos, Ludvig Holberg, Ludwig Wittgenstein, Many-sorted logic, Many-valued logic, Material conditional, Material inference, Mathematical logic, Mathematical model, Mathematical notation, Mathematics, Mechanics, Metalogic, Metaphysics, Michael Dummett, Modal fallacy, Modal logic, Model theory, Modus ponens, Monotonicity of entailment, Natural language, Navya-Nyāya, Necessity and sufficiency, Negation, Nicholas Rescher, Nicolai A. Vasiliev, Non-classical logic, Nuel Belnap, Nyaya, On Truth and Lies in a Nonmoral Sense, Online Etymology Dictionary, Organon, Outline of logic, Outline of mathematics, Outline of philosophy, Paraconsistent logic, Paradox, Paradoxes of material implication, Perseus Project, Philo the Dialectician, Philosophical logic, Philosophical realism, Philosophical skepticism, Philosophy, Philosophy of mathematics, Philosophy of mind, Plato, Port-Royal Logic, Posterior Analytics, Potentiality and actuality, Pragma-dialectics, Predicable, Principia Mathematica, Principle of bivalence, Principle of distributivity, Principle of explosion, Principles of Mathematical Logic, Prior Analytics, Problem of future contingents, Problem of multiple generality, Programming language, Prolog, Proof calculus, Proof theory, Proof-theoretic semantics, Proposition, Propositional calculus, Psychologism, Psychology, Qin dynasty, Quantifier (logic), Quantum logic, Rationality, Real number, Reason, Relevance logic, Rhetoric, Rival conceptions of logic, Robert Brandom, Routledge, Rule induction, Rule of inference, Russell's paradox, Saul Kripke, Scholasticism, Second-order logic, Semantic theory of truth, Semantics, Semantics (computer science), Set theory, Sextus Empiricus, Soundness, Southern Illinois University Press, Stanford Encyclopedia of Philosophy, Stephen Toulmin, Stewart Shapiro, Stoic logic, Stoicism, Strict conditional, Structural proof theory, Structure (mathematical logic), Sum of Logic, Supervaluationism, Supposition theory, Susan Haack, Syllogism, Tautology (logic), Temporal logic, Term logic, Terminology, Tetralemma, The Gay Science, The Laws of Thought, Three-valued logic, Topics (Aristotle), Truth, Truth value, Turing degree, Universal logic, Universal quantification, University of California Press, Validity, Vector logic, Walter Burley, Wilfrid Hodges, Wilfrid Sellars, Wilhelm Ackermann, Willard Van Orman Quine, William Kneale, William of Ockham, William Wallace (philosopher). Expand index (239 more) »

A Greek–English Lexicon

A Greek–English Lexicon, often referred to as Liddell & Scott, Liddell–Scott–Jones, or LSJ, is a standard lexicographical work of the Ancient Greek language.

New!!: Logic and A Greek–English Lexicon · See more »

Abductive reasoning

Abductive reasoning (also called abduction,For example: abductive inference, or retroduction) is a form of logical inference which starts with an observation or set of observations then seeks to find the simplest and most likely explanation.

New!!: Logic and Abductive reasoning · See more »

ACM Computing Classification System

The ACM Computing Classification System (CCS) is a subject classification system for computing devised by the Association for Computing Machinery (ACM).

New!!: Logic and ACM Computing Classification System · See more »

Alan Turing

Alan Mathison Turing (23 June 1912 – 7 June 1954) was an English computer scientist, mathematician, logician, cryptanalyst, philosopher, and theoretical biologist.

New!!: Logic and Alan Turing · See more »

Alfred North Whitehead

Alfred North Whitehead (15 February 1861 – 30 December 1947) was an English mathematician and philosopher.

New!!: Logic and Alfred North Whitehead · See more »

Alfred Tarski

Alfred Tarski (January 14, 1901 – October 26, 1983), born Alfred Teitelbaum,School of Mathematics and Statistics, University of St Andrews,, School of Mathematics and Statistics, University of St Andrews.

New!!: Logic and Alfred Tarski · See more »

Ammonius Saccas

Ammonius Saccas (Ἀμμώνιος Σακκᾶς; fl. 3rd century AD) was a Greek philosopher from Alexandria who was often referred to as one of the founders of Neoplatonism.

New!!: Logic and Ammonius Saccas · See more »

An Essay Concerning Human Understanding

An Essay Concerning Human Understanding is a work by John Locke concerning the foundation of human knowledge and understanding.

New!!: Logic and An Essay Concerning Human Understanding · See more »

Analytic philosophy

Analytic philosophy (sometimes analytical philosophy) is a style of philosophy that became dominant in the Western world at the beginning of the 20th century.

New!!: Logic and Analytic philosophy · See more »

Annals of Mathematics

The Annals of Mathematics is a bimonthly mathematical journal published by Princeton University and the Institute for Advanced Study.

New!!: Logic and Annals of Mathematics · See more »


In analytic philosophy, anti-realism is an epistemological position first articulated by British philosopher Michael Dummett.

New!!: Logic and Anti-realism · See more »

Antoine Arnauld

Antoine Arnauld (6 February 16128 August 1694) was a French Roman Catholic theologian, philosopher and mathematician.

New!!: Logic and Antoine Arnauld · See more »


Ānvīkṣikī is a term in Sanskrit denoting roughly the "science of inquiry" and it should have been recognized in India as a distinct branch of learning as early as 650 BCE.

New!!: Logic and Anviksiki · See more »

Arend Heyting

__notoc__ Arend Heyting (9 May 1898 – 9 July 1980) was a Dutch mathematician and logician.

New!!: Logic and Arend Heyting · See more »


In logic and philosophy, an argument is a series of statements typically used to persuade someone of something or to present reasons for accepting a conclusion.

New!!: Logic and Argument · See more »

Argumentation theory

Argumentation theory, or argumentation, is the interdisciplinary study of how conclusions can be reached through logical reasoning; that is, claims based, soundly or not, on premises.

New!!: Logic and Argumentation theory · See more »


Aristotle (Ἀριστοτέλης Aristotélēs,; 384–322 BC) was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidiki, in the north of Classical Greece.

New!!: Logic and Aristotle · See more »


Arithmetic (from the Greek ἀριθμός arithmos, "number") is a branch of mathematics that consists of the study of numbers, especially the properties of the traditional operations on them—addition, subtraction, multiplication and division.

New!!: Logic and Arithmetic · See more »

Arithmetic logic unit

An arithmetic logic unit (ALU) is a combinational digital electronic circuit that performs arithmetic and bitwise operations on integer binary numbers.

New!!: Logic and Arithmetic logic unit · See more »

Arthur Prior

Arthur Norman Prior (4 December 1914 – 6 October 1969), usually cited as A. N. Prior, was a noted logician and philosopher.

New!!: Logic and Arthur Prior · See more »

Artificial intelligence

Artificial intelligence (AI, also machine intelligence, MI) is intelligence demonstrated by machines, in contrast to the natural intelligence (NI) displayed by humans and other animals.

New!!: Logic and Artificial intelligence · See more »

Atomic sentence

In logic, an atomic sentence is a type of declarative sentence which is either true or false (may also be referred to as a proposition, statement or truthbearer) and which cannot be broken down into other simpler sentences.

New!!: Logic and Atomic sentence · See more »

Augustus De Morgan

Augustus De Morgan (27 June 1806 – 18 March 1871) was a British mathematician and logician.

New!!: Logic and Augustus De Morgan · See more »

Automated theorem proving

Automated theorem proving (also known as ATP or automated deduction) is a subfield of automated reasoning and mathematical logic dealing with proving mathematical theorems by computer programs.

New!!: Logic and Automated theorem proving · See more »


Avicenna (also Ibn Sīnā or Abu Ali Sina; ابن سینا; – June 1037) was a Persian polymath who is regarded as one of the most significant physicians, astronomers, thinkers and writers of the Islamic Golden Age.

New!!: Logic and Avicenna · See more »


An axiom or postulate is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments.

New!!: Logic and Axiom · See more »

Axiom of choice

In mathematics, the axiom of choice, or AC, is an axiom of set theory equivalent to the statement that the Cartesian product of a collection of non-empty sets is non-empty.

New!!: Logic and Axiom of choice · See more »

Barber paradox

The barber paradox is a puzzle derived from Russell's paradox.

New!!: Logic and Barber paradox · See more »

Barry Smith (academic)

Barry Smith (born June 4, 1952) is an academic working in the fields of ontology and biomedical informatics.

New!!: Logic and Barry Smith (academic) · See more »


Begriffsschrift (German for, roughly, "concept-script") is a book on logic by Gottlob Frege, published in 1879, and the formal system set out in that book.

New!!: Logic and Begriffsschrift · See more »

Bertrand Russell

Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, historian, writer, social critic, political activist, and Nobel laureate.

New!!: Logic and Bertrand Russell · See more »


Anicius Manlius Severinus Boëthius, commonly called Boethius (also Boetius; 477–524 AD), was a Roman senator, consul, magister officiorum, and philosopher of the early 6th century.

New!!: Logic and Boethius · See more »

Boolean algebra

In mathematics and mathematical logic, Boolean algebra is the branch of algebra in which the values of the variables are the truth values true and false, usually denoted 1 and 0 respectively.

New!!: Logic and Boolean algebra · See more »

Cambridge University Press

Cambridge University Press (CUP) is the publishing business of the University of Cambridge.

New!!: Logic and Cambridge University Press · See more »

Cantor's theorem

In elementary set theory, Cantor's theorem is a fundamental result that states that, for any set A, the set of all subsets of A (the power set of A, denoted by \mathcal(A)) has a strictly greater cardinality than A itself.

New!!: Logic and Cantor's theorem · See more »

Charles Babbage

Charles Babbage (26 December 1791 – 18 October 1871) was an English polymath.

New!!: Logic and Charles Babbage · See more »

Charles Sanders Peirce

Charles Sanders Peirce ("purse"; 10 September 1839 – 19 April 1914) was an American philosopher, logician, mathematician, and scientist who is sometimes known as "the father of pragmatism".

New!!: Logic and Charles Sanders Peirce · See more »


A Christian is a person who follows or adheres to Christianity, an Abrahamic, monotheistic religion based on the life and teachings of Jesus Christ.

New!!: Logic and Christian · See more »

Church–Turing thesis

In computability theory, the Church–Turing thesis (also known as computability thesis, the Turing–Church thesis, the Church–Turing conjecture, Church's thesis, Church's conjecture, and Turing's thesis) is a hypothesis about the nature of computable functions.

New!!: Logic and Church–Turing thesis · See more »

Clarence Irving Lewis

Clarence Irving Lewis (April 12, 1883 – February 3, 1964), usually cited as C. I. Lewis, was an American academic philosopher and the founder of conceptual pragmatism.

New!!: Logic and Clarence Irving Lewis · See more »

Classical logic

Classical logic (or standard logic) is an intensively studied and widely used class of formal logics.

New!!: Logic and Classical logic · See more »

Completeness (logic)

In mathematical logic and metalogic, a formal system is called complete with respect to a particular property if every formula having the property can be derived using that system, i.e. is one of its theorems; otherwise the system is said to be incomplete.

New!!: Logic and Completeness (logic) · See more »

Complexity class

In computational complexity theory, a complexity class is a set of problems of related resource-based complexity.

New!!: Logic and Complexity class · See more »

Computability theory

Computability theory, also known as recursion theory, is a branch of mathematical logic, of computer science, and of the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees.

New!!: Logic and Computability theory · See more »

Computational linguistics

Computational linguistics is an interdisciplinary field concerned with the statistical or rule-based modeling of natural language from a computational perspective, as well as the study of appropriate computational approaches to linguistic questions.

New!!: Logic and Computational linguistics · See more »

Computer science

Computer science deals with the theoretical foundations of information and computation, together with practical techniques for the implementation and application of these foundations.

New!!: Logic and Computer science · See more »


A consequent is the second half of a hypothetical proposition.

New!!: Logic and Consequent · See more »


In classical deductive logic, a consistent theory is one that does not contain a contradiction.

New!!: Logic and Consistency · See more »

Continuum hypothesis

In mathematics, the continuum hypothesis (abbreviated CH) is a hypothesis about the possible sizes of infinite sets.

New!!: Logic and Continuum hypothesis · See more »

Cooperative principle

In social science generally and linguistics specifically, the cooperative principle describes how effective communication in conversation is achieved in common social situations, that is, how listeners and speakers must act cooperatively and mutually accept one another to be understood in a particular way.

New!!: Logic and Cooperative principle · See more »

Critical thinking

Critical thinking is the objective analysis of facts to form a judgment.

New!!: Logic and Critical thinking · See more »

Curry–Howard correspondence

In programming language theory and proof theory, the Curry–Howard correspondence (also known as the Curry–Howard isomorphism or equivalence, or the proofs-as-programs and propositions- or formulae-as-types interpretation) is the direct relationship between computer programs and mathematical proofs.

New!!: Logic and Curry–Howard correspondence · See more »

David Hilbert

David Hilbert (23 January 1862 – 14 February 1943) was a German mathematician.

New!!: Logic and David Hilbert · See more »

De Interpretatione

De Interpretatione or On Interpretation (Greek: Περὶ Ἑρμηνείας, Peri Hermeneias) is the second text from Aristotle's Organon and is among the earliest surviving philosophical works in the Western tradition to deal with the relationship between language and logic in a comprehensive, explicit, and formal way.

New!!: Logic and De Interpretatione · See more »

Decision tree

A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility.

New!!: Logic and Decision tree · See more »

Deductive reasoning

Deductive reasoning, also deductive logic, logical deduction is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion.

New!!: Logic and Deductive reasoning · See more »

Default logic

Default logic is a non-monotonic logic proposed by Raymond Reiter to formalize reasoning with default assumptions.

New!!: Logic and Default logic · See more »

Defeasible reasoning

In logic, defeasible reasoning is a kind of reasoning that is rationally compelling, though not deductively valid.

New!!: Logic and Defeasible reasoning · See more »

Deontic logic

Deontic logic is the field of philosophical logic that is concerned with obligation, permission, and related concepts.

New!!: Logic and Deontic logic · See more »

Description logic

Description logics (DL) are a family of formal knowledge representation languages.

New!!: Logic and Description logic · See more »


Dialectic or dialectics (διαλεκτική, dialektikḗ; related to dialogue), also known as the dialectical method, is at base a discourse between two or more people holding different points of view about a subject but wishing to establish the truth through reasoned arguments.

New!!: Logic and Dialectic · See more »

Dialectical logic

Dialectical logic is the system of laws of thought, developed within the Hegelian and Marxist traditions, which seeks to supplement or replace the laws of formal logic.

New!!: Logic and Dialectical logic · See more »


Dialetheism is the view that there are statements which are both true and false.

New!!: Logic and Dialetheism · See more »

Digital electronics

Digital electronics or digital (electronic) circuits are electronics that operate on digital signals.

New!!: Logic and Digital electronics · See more »

Domain of discourse

In the formal sciences, the domain of discourse, also called the universe of discourse, universal set, or simply universe, is the set of entities over which certain variables of interest in some formal treatment may range.

New!!: Logic and Domain of discourse · See more »

Dov Gabbay

Dov M. Gabbay (born October 23, 1945) is a British logician.

New!!: Logic and Dov Gabbay · See more »

Dynamic logic (modal logic)

Dynamic logic is an extension of modal logic originally intended for reasoning about computer programs and later applied to more general complex behaviors arising in linguistics, philosophy, AI, and other fields.

New!!: Logic and Dynamic logic (modal logic) · See more »

Edward N. Zalta

Edward N. Zalta (born March 16, 1952) is a senior research scholar at the Center for the Study of Language and Information.

New!!: Logic and Edward N. Zalta · See more »

Elliott Mendelson

Elliott Mendelson (born 1931) is an American logician.

New!!: Logic and Elliott Mendelson · See more »

Encyclopædia Britannica

The Encyclopædia Britannica (Latin for "British Encyclopaedia"), published by Encyclopædia Britannica, Inc., is a general knowledge English-language encyclopaedia.

New!!: Logic and Encyclopædia Britannica · See more »


In mathematics and computer science, the Entscheidungsproblem (German for "decision problem") is a challenge posed by David Hilbert in 1928.

New!!: Logic and Entscheidungsproblem · See more »

Epistemic modal logic

Epistemic modal logic is a subfield of modal logic that is concerned with reasoning about knowledge.

New!!: Logic and Epistemic modal logic · See more »


Epistemology is the branch of philosophy concerned with the theory of knowledge.

New!!: Logic and Epistemology · See more »

Erasmus Montanus

Erasmus Montanus is a satirical play about academic conceit in rural Denmark, written by Ludvig Holberg in 1722.

New!!: Logic and Erasmus Montanus · See more »


Euclid (Εὐκλείδης Eukleidēs; fl. 300 BC), sometimes given the name Euclid of Alexandria to distinguish him from Euclides of Megara, was a Greek mathematician, often referred to as the "founder of geometry" or the "father of geometry".

New!!: Logic and Euclid · See more »


Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere.

New!!: Logic and Europe · See more »


A fallacy is the use of invalid or otherwise faulty reasoning, or "wrong moves" in the construction of an argument.

New!!: Logic and Fallacy · See more »

First-order logic

First-order logic—also known as first-order predicate calculus and predicate logic—is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science.

New!!: Logic and First-order logic · See more »

Formal methods

In computer science, specifically software engineering and hardware engineering, formal methods are a particular kind of mathematically based techniques for the specification, development and verification of software and hardware systems.

New!!: Logic and Formal methods · See more »

Formal system

A formal system is the name of a logic system usually defined in the mathematical way.

New!!: Logic and Formal system · See more »


In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a chemical formula.

New!!: Logic and Formula · See more »

Foundations of mathematics

Foundations of mathematics is the study of the philosophical and logical and/or algorithmic basis of mathematics, or, in a broader sense, the mathematical investigation of what underlies the philosophical theories concerning the nature of mathematics.

New!!: Logic and Foundations of mathematics · See more »

Free logic

A free logic is a logic with fewer existential presuppositions than classical logic.

New!!: Logic and Free logic · See more »

Friedrich Nietzsche

Friedrich Wilhelm Nietzsche (15 October 1844 – 25 August 1900) was a German philosopher, cultural critic, composer, poet, philologist and a Latin and Greek scholar whose work has exerted a profound influence on Western philosophy and modern intellectual history.

New!!: Logic and Friedrich Nietzsche · See more »

Fuzzy logic

Fuzzy logic is a form of many-valued logic in which the truth values of variables may be any real number between 0 and 1.

New!!: Logic and Fuzzy logic · See more »

Game semantics

Game semantics (dialogische Logik, translated as dialogical logic) is an approach to formal semantics that grounds the concepts of truth or validity on game-theoretic concepts, such as the existence of a winning strategy for a player, somewhat resembling Socratic dialogues or medieval theory of Obligationes.

New!!: Logic and Game semantics · See more »

Garrett Birkhoff

Garrett Birkhoff (January 19, 1911 – November 22, 1996) was an American mathematician.

New!!: Logic and Garrett Birkhoff · See more »

Gödel's completeness theorem

Gödel's completeness theorem is a fundamental theorem in mathematical logic that establishes a correspondence between semantic truth and syntactic provability in first-order logic.

New!!: Logic and Gödel's completeness theorem · See more »

Gödel's incompleteness theorems

Gödel's incompleteness theorems are two theorems of mathematical logic that demonstrate the inherent limitations of every formal axiomatic system containing basic arithmetic.

New!!: Logic and Gödel's incompleteness theorems · See more »

General relativity

General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.

New!!: Logic and General relativity · See more »


Geometry (from the γεωμετρία; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.

New!!: Logic and Geometry · See more »

Georg Cantor

Georg Ferdinand Ludwig Philipp Cantor (– January 6, 1918) was a German mathematician.

New!!: Logic and Georg Cantor · See more »

Georg Wilhelm Friedrich Hegel

Georg Wilhelm Friedrich Hegel (August 27, 1770 – November 14, 1831) was a German philosopher and the most important figure of German idealism.

New!!: Logic and Georg Wilhelm Friedrich Hegel · See more »

George Boole

George Boole (2 November 1815 – 8 December 1864) was a largely self-taught English mathematician, philosopher and logician, most of whose short career was spent as the first professor of mathematics at Queen's College, Cork in Ireland.

New!!: Logic and George Boole · See more »

George Boolos

George Stephen Boolos (September 4, 1940 – May 27, 1996) was an American philosopher and a mathematical logician who taught at the Massachusetts Institute of Technology.

New!!: Logic and George Boolos · See more »

Gerhard Gentzen

Gerhard Karl Erich Gentzen (November 24, 1909 – August 4, 1945) was a German mathematician and logician.

New!!: Logic and Gerhard Gentzen · See more »

Gongsun Long

Gongsun Long (BC) was a member of the School of Names (Logicians) of ancient Chinese philosophy.

New!!: Logic and Gongsun Long · See more »

Gottfried Wilhelm Leibniz

Gottfried Wilhelm (von) Leibniz (or; Leibnitz; – 14 November 1716) was a German polymath and philosopher who occupies a prominent place in the history of mathematics and the history of philosophy.

New!!: Logic and Gottfried Wilhelm Leibniz · See more »

Gottlob Frege

Friedrich Ludwig Gottlob Frege (8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician.

New!!: Logic and Gottlob Frege · See more »

Graham Priest

Graham Priest (born 1948) is Distinguished Professor of Philosophy at the CUNY Graduate Center, as well as a regular visitor at the University of Melbourne where he was Boyce Gibson Professor of Philosophy and also at the University of St Andrews.

New!!: Logic and Graham Priest · See more »

Graph theory

In mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects.

New!!: Logic and Graph theory · See more »

György Lukács

György Lukács (also Georg Lukács; born György Bernát Löwinger; 13 April 1885 – 4 June 1971) was a Hungarian Marxist philosopher, aesthetician, literary historian, and critic.

New!!: Logic and György Lukács · See more »

Han Feizi

The Han Feizi is an ancient Chinese text attributed to foundational political philosopher, "Master" Han Fei.

New!!: Logic and Han Feizi · See more »

Harvard University Press

Harvard University Press (HUP) is a publishing house established on January 13, 1913, as a division of Harvard University, and focused on academic publishing.

New!!: Logic and Harvard University Press · See more »

High Middle Ages

The High Middle Ages, or High Medieval Period, was the period of European history that commenced around 1000 AD and lasted until around 1250 AD.

New!!: Logic and High Middle Ages · See more »

Hilary Putnam

Hilary Whitehall Putnam (July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, and computer scientist, and a major figure in analytic philosophy in the second half of the 20th century.

New!!: Logic and Hilary Putnam · See more »

Hilbert's program

In mathematics, Hilbert's program, formulated by German mathematician David Hilbert in the early part of the 20th century, was a proposed solution to the foundational crisis of mathematics, when early attempts to clarify the foundations of mathematics were found to suffer from paradoxes and inconsistencies.

New!!: Logic and Hilbert's program · See more »

Hoare logic

Hoare logic (also known as Floyd–Hoare logic or Hoare rules) is a formal system with a set of logical rules for reasoning rigorously about the correctness of computer programs.

New!!: Logic and Hoare logic · See more »

Horn clause

In mathematical logic and logic programming, a Horn clause is a logical formula of a particular rule-like form which gives it useful properties for use in logic programming, formal specification, and model theory.

New!!: Logic and Horn clause · See more »

Human, All Too Human

Human, All Too Human: A Book for Free Spirits (Menschliches, Allzumenschliches: Ein Buch für freie Geister) is a book by 19th-century philosopher Friedrich Nietzsche, originally published in 1878.

New!!: Logic and Human, All Too Human · See more »

Hypothetical syllogism

In classical logic, hypothetical syllogism is a valid argument form which is a syllogism having a conditional statement for one or both of its premises.

New!!: Logic and Hypothetical syllogism · See more »

If and only if

In logic and related fields such as mathematics and philosophy, if and only if (shortened iff) is a biconditional logical connective between statements.

New!!: Logic and If and only if · See more »

Immanuel Kant

Immanuel Kant (22 April 1724 – 12 February 1804) was a German philosopher who is a central figure in modern philosophy.

New!!: Logic and Immanuel Kant · See more »

Indian logic

The development of Indian logic dates back to the anviksiki of Medhatithi Gautama (c. 6th century BCE) the Sanskrit grammar rules of Pāṇini (c. 5th century BCE); the Vaisheshika school's analysis of atomism (c. 6th century BCE to 2nd century BCE); the analysis of inference by Gotama (c. 6th century BC to 2nd century CE), founder of the Nyaya school of Hindu philosophy; and the tetralemma of Nagarjuna (c. 2nd century CE).

New!!: Logic and Indian logic · See more »


An individual is that which exists as a distinct entity.

New!!: Logic and Individual · See more »

Inductive reasoning

Inductive reasoning (as opposed to ''deductive'' reasoning or ''abductive'' reasoning) is a method of reasoning in which the premises are viewed as supplying some evidence for the truth of the conclusion.

New!!: Logic and Inductive reasoning · See more »


Inferences are steps in reasoning, moving from premises to logical consequences.

New!!: Logic and Inference · See more »

Infinitary logic

An infinitary logic is a logic that allows infinitely long statements and/or infinitely long proofs.

New!!: Logic and Infinitary logic · See more »

Informal logic

Informal logic, intuitively, refers to the principles of logic and logical thought outside of a formal setting.

New!!: Logic and Informal logic · See more »


In the philosophy of mathematics, intuitionism, or neointuitionism (opposed to preintuitionism), is an approach where mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality.

New!!: Logic and Intuitionism · See more »

Intuitionistic logic

Intuitionistic logic, sometimes more generally called constructive logic, refers to systems of symbolic logic that differ from the systems used for classical logic by more closely mirroring the notion of constructive proof.

New!!: Logic and Intuitionistic logic · See more »

Is Logic Empirical?

"Is Logic Empirical?" is the title of two articles (one by Hilary Putnam and another by Michael Dummett) 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.

New!!: Logic and Is Logic Empirical? · See more »

Jan Łukasiewicz

Jan Łukasiewicz (21 December 1878 – 13 February 1956) was a Polish logician and philosopher born in Lwów, a city in the Galician kingdom of Austria-Hungary.

New!!: Logic and Jan Łukasiewicz · See more »

Józef Maria Bocheński

Józef Maria Bocheński (Czuszów, Congress Poland, Russian Empire, 30 August 1902 – 8 February 1995, Fribourg, Switzerland) was a Polish Dominican, logician and philosopher.

New!!: Logic and Józef Maria Bocheński · See more »

Jürgen Habermas

Jürgen Habermas (born 18 June 1929) is a German sociologist and philosopher in the tradition of critical theory and pragmatism.

New!!: Logic and Jürgen Habermas · See more »

John Locke

John Locke (29 August 1632 – 28 October 1704) was an English philosopher and physician, widely regarded as one of the most influential of Enlightenment thinkers and commonly known as the "Father of Liberalism".

New!!: Logic and John Locke · See more »

John von Neumann

John von Neumann (Neumann János Lajos,; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, and polymath.

New!!: Logic and John von Neumann · See more »

Jon Barwise

Kenneth Jon Barwise (June 29, 1942 – March 5, 2000) was an American mathematician, philosopher and logician who proposed some fundamental revisions to the way that logic is understood and used.

New!!: Logic and Jon Barwise · See more »

Joseph Goguen

Joseph Amadee Goguen (28 June 1941 – 3 July 2006) was a US computer scientist.

New!!: Logic and Joseph Goguen · See more »

Karl Marx

Karl MarxThe name "Karl Heinrich Marx", used in various lexicons, is based on an error.

New!!: Logic and Karl Marx · See more »

Knowledge representation and reasoning

Knowledge representation and reasoning (KR, KR², KR&R) is the field of artificial intelligence (AI) dedicated to representing information about the world in a form that a computer system can utilize to solve complex tasks such as diagnosing a medical condition or having a dialog in a natural language.

New!!: Logic and Knowledge representation and reasoning · See more »

Kripke semantics

Kripke semantics (also known as relational semantics or frame semantics, and often confused with possible world semantics) is a formal semantics for non-classical logic systems created in the late 1950s and early 1960s by Saul Kripke and André Joyal.

New!!: Logic and Kripke semantics · See more »

Kurt Gödel

Kurt Friedrich Gödel (April 28, 1906 – January 14, 1978) was an Austrian, and later American, logician, mathematician, and philosopher.

New!!: Logic and Kurt Gödel · See more »

L. E. J. Brouwer

Luitzen Egbertus Jan Brouwer (27 February 1881 – 2 December 1966), usually cited as L. E. J. Brouwer but known to his friends as Bertus, was a Dutch mathematician and philosopher, who worked in topology, set theory, measure theory and complex analysis.

New!!: Logic and L. E. J. Brouwer · See more »

Large cardinal

In the mathematical field of set theory, a large cardinal property is a certain kind of property of transfinite cardinal numbers.

New!!: Logic and Large cardinal · See more »


Law is a system of rules that are created and enforced through social or governmental institutions to regulate behavior.

New!!: Logic and Law · See more »

Law of excluded middle

In logic, the law of excluded middle (or the principle of excluded middle) states that for any proposition, either that proposition is true or its negation is true.

New!!: Logic and Law of excluded middle · See more »

Law of noncontradiction

In classical logic, the law of non-contradiction (LNC) (also known as the law of contradiction, principle of non-contradiction (PNC), or the principle of contradiction) states that contradictory statements cannot both be true in the same sense at the same time, e.g. the two propositions "A is B" and "A is not B" are mutually exclusive.

New!!: Logic and Law of noncontradiction · See more »

Lewis Carroll

Charles Lutwidge Dodgson (27 January 1832 – 14 January 1898), better known by his pen name Lewis Carroll, was an English writer, mathematician, logician, Anglican deacon, and photographer.

New!!: Logic and Lewis Carroll · See more »

Linguistic modality

In linguistics, modality is a feature of language that allows for communicating things about, or based on, situations which need not be actual.

New!!: Logic and Linguistic modality · See more »


Linguistics is the scientific study of language, and involves an analysis of language form, language meaning, and language in context.

New!!: Logic and Linguistics · See more »

List of logic journals

This is a list of academic journals in logic.

New!!: Logic and List of logic journals · See more »

List of logic symbols

In logic, a set of symbols is commonly used to express logical representation.

New!!: Logic and List of logic symbols · See more »

List of logicians

A logician is a person whose topic of scholarly study is logic.

New!!: Logic and List of logicians · See more »

Lists of mathematics topics

This article itemizes the various lists of mathematics topics.

New!!: Logic and Lists of mathematics topics · See more »

Logic gate

In electronics, a logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more binary inputs and produces a single binary output.

New!!: Logic and Logic gate · See more »

Logic in China

Formal logic in China has a special place in the history of logic due to its repression and abandonment—in contrast to the strong ancient adoption and continued development of the study of logic in Europe, India, and the Islamic world.

New!!: Logic and Logic in China · See more »

Logic programming

Logic programming is a type of programming paradigm which is largely based on formal logic.

New!!: Logic and Logic programming · See more »

Logic puzzle

A logic puzzle is a puzzle deriving from the mathematics field of deduction.

New!!: Logic and Logic puzzle · See more »

Logica Universalis

Logica Universalis is a peer-reviewed academic journal which covers research related to Universal logic.

New!!: Logic and Logica Universalis · See more »

Logical biconditional

In logic and mathematics, the logical biconditional (sometimes known as the material biconditional) is the logical connective of two statements asserting "P if and only if Q", where P is an antecedent and Q is a consequent.

New!!: Logic and Logical biconditional · See more »

Logical conjunction

In logic, mathematics and linguistics, And (∧) is the truth-functional operator of logical conjunction; the and of a set of operands is true if and only if all of its operands are true.

New!!: Logic and Logical conjunction · See more »

Logical connective

In logic, a logical connective (also called a logical operator, sentential connective, or sentential operator) is a symbol or word used to connect two or more sentences (of either a formal or a natural language) in a grammatically valid way, such that the value of the compound sentence produced depends only on that of the original sentences and on the meaning of the connective.

New!!: Logic and Logical connective · See more »

Logical consequence

Logical consequence (also entailment) is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically follows from one or more statements.

New!!: Logic and Logical consequence · See more »

Logical disjunction

In logic and mathematics, or is the truth-functional operator of (inclusive) disjunction, also known as alternation; the or of a set of operands is true if and only if one or more of its operands is true.

New!!: Logic and Logical disjunction · See more »

Logical form

In philosophy and mathematics, a logical form of a syntactic expression is a precisely-specified semantic version of that expression in a formal system.

New!!: Logic and Logical form · See more »

Logical truth

Logical truth is one of the most fundamental concepts in logic, and there are different theories on its nature.

New!!: Logic and Logical truth · See more »


Logicism is one of the schools of thought in the philosophy of mathematics, putting forth the theory that mathematics is an extension of logic and therefore some or all mathematics is reducible to logic.

New!!: Logic and Logicism · See more »


Logos (lógos; from λέγω) is a term in Western philosophy, psychology, rhetoric, and religion derived from a Greek word variously meaning "ground", "plea", "opinion", "expectation", "word", "speech", "account", "reason", "proportion", and "discourse",Henry George Liddell and Robert Scott,: logos, 1889.

New!!: Logic and Logos · See more »

Ludvig Holberg

Ludvig Holberg, Baron of Holberg (3 December 1684 – 28 January 1754) was a writer, essayist, philosopher, historian and playwright born in Bergen, Norway, during the time of the Dano-Norwegian dual monarchy.

New!!: Logic and Ludvig Holberg · See more »

Ludwig Wittgenstein

Ludwig Josef Johann Wittgenstein (26 April 1889 – 29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.

New!!: Logic and Ludwig Wittgenstein · See more »

Many-sorted logic

Many-sorted logic can reflect formally our intention not to handle the universe as a homogeneous collection of objects, but to partition it in a way that is similar to types in typeful programming.

New!!: Logic and Many-sorted logic · See more »

Many-valued logic

In logic, a many-valued logic (also multi- or multiple-valued logic) is a propositional calculus in which there are more than two truth values.

New!!: Logic and Many-valued logic · See more »

Material conditional

The material conditional (also known as material implication, material consequence, or simply implication, implies, or conditional) is a logical connective (or a binary operator) that is often symbolized by a forward arrow "→".

New!!: Logic and Material conditional · See more »

Material inference

In logic, inference is the process of deriving logical conclusions from premises known or assumed to be true.

New!!: Logic and Material inference · See more »

Mathematical logic

Mathematical logic is a subfield of mathematics exploring the applications of formal logic to mathematics.

New!!: Logic and Mathematical logic · See more »

Mathematical model

A mathematical model is a description of a system using mathematical concepts and language.

New!!: Logic and Mathematical model · See more »

Mathematical notation

Mathematical notation is a system of symbolic representations of mathematical objects and ideas.

New!!: Logic and Mathematical notation · See more »


Mathematics (from Greek μάθημα máthēma, "knowledge, study, learning") is the study of such topics as quantity, structure, space, and change.

New!!: Logic and Mathematics · See more »


Mechanics (Greek μηχανική) is that area of science concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment.

New!!: Logic and Mechanics · See more »


Metalogic is the study of the metatheory of logic.

New!!: Logic and Metalogic · See more »


Metaphysics is a branch of philosophy that explores the nature of being, existence, and reality.

New!!: Logic and Metaphysics · See more »

Michael Dummett

Sir Michael Anthony Eardley Dummett, FBA (27 June 192527 December 2011) was an English philosopher, described as "among the most significant British philosophers of the last century and a leading campaigner for racial tolerance and equality." He was, until 1992, Wykeham Professor of Logic at the University of Oxford.

New!!: Logic and Michael Dummett · See more »

Modal fallacy

The formal fallacy of the modal fallacy is a special type of fallacy that occurs in modal logic.

New!!: Logic and Modal fallacy · See more »

Modal logic

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.

New!!: Logic and Modal logic · See more »

Model theory

In mathematics, model theory is the study of classes of mathematical structures (e.g. groups, fields, graphs, universes of set theory) from the perspective of mathematical logic.

New!!: Logic and Model theory · See more »

Modus ponens

In propositional logic, modus ponens (MP; also modus ponendo ponens (Latin for "mode that affirms by affirming") or implication elimination) is a rule of inference.

New!!: Logic and Modus ponens · See more »

Monotonicity of entailment

Monotonicity of entailment is a property of many logical systems that states that the hypotheses of any derived fact may be freely extended with additional assumptions.

New!!: Logic and Monotonicity of entailment · See more »

Natural language

In neuropsychology, linguistics, and the philosophy of language, a natural language or ordinary language is any language that has evolved naturally in humans through use and repetition without conscious planning or premeditation.

New!!: Logic and Natural language · See more »


The Navya-Nyāya or Neo-Logical darśana (view, system, or school) of Indian logic and Indian philosophy was founded in the 13th century CE by the philosopher Gangeśa Upādhyāya of Mithila and continued by Raghunatha Siromani.

New!!: Logic and Navya-Nyāya · See more »

Necessity and sufficiency

In logic, necessity and sufficiency are terms used to describe an implicational relationship between statements.

New!!: Logic and Necessity and sufficiency · See more »


In logic, negation, also called the logical complement, is an operation that takes a proposition P to another proposition "not P", written \neg P (¬P), which is interpreted intuitively as being true when P is false, and false when P is true.

New!!: Logic and Negation · See more »

Nicholas Rescher

Nicholas Rescher (born 15 July 1928) is a German-American philosopher at the University of Pittsburgh.

New!!: Logic and Nicholas Rescher · See more »

Nicolai A. Vasiliev

Nicolai Alexandrovich Vasiliev (Николай Александрович Васильев), also Vasil'ev, Vassilieff, Wassilieff (– December 31, 1940), was a Russian logician, philosopher, psychologist, poet.

New!!: Logic and Nicolai A. Vasiliev · See more »

Non-classical logic

Non-classical logics (and sometimes alternative logics) are formal systems that differ in a significant way from standard logical systems such as propositional and predicate logic.

New!!: Logic and Non-classical logic · See more »

Nuel Belnap

Nuel D. Belnap Jr. (born 1930) is an American logician and philosopher who has made contributions to the philosophy of logic, temporal logic, and structural proof theory.

New!!: Logic and Nuel Belnap · See more »


(Sanskrit: न्याय, ny-āyá), literally means "rules", "method" or "judgment".

New!!: Logic and Nyaya · See more »

On Truth and Lies in a Nonmoral Sense

On Truth and Lies in a Nonmoral Sense (Über Wahrheit und Lüge im aussermoralischen Sinne, also called On Truth and Lie in an Extra-Moral SenseWalter Kaufmann's translation, appearing in The Portable Nietzsche, 1976 edition. Viking Press.) is a philosophical essay by Friedrich Nietzsche.

New!!: Logic and On Truth and Lies in a Nonmoral Sense · See more »

Online Etymology Dictionary

The Online Etymology Dictionary is a free online dictionary written and compiled by Douglas Harper that describes the origins of English-language words.

New!!: Logic and Online Etymology Dictionary · See more »


The Organon (Greek: Ὄργανον, meaning "instrument, tool, organ") is the standard collection of Aristotle's six works on logic.

New!!: Logic and Organon · See more »

Outline of logic

Logic is the formal science of using reason and is considered a branch of both philosophy and mathematics.

New!!: Logic and Outline of logic · See more »

Outline of mathematics

Mathematics is a field of study that investigates topics including number, space, structure, and change.

New!!: Logic and Outline of mathematics · See more »

Outline of philosophy

The following outline is provided as an overview of and topical guide to philosophy: Philosophy – study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language.

New!!: Logic and Outline of philosophy · See more »

Paraconsistent logic

A paraconsistent logic is a logical system that attempts to deal with contradictions in a discriminating way.

New!!: Logic and Paraconsistent logic · See more »


A paradox is a statement that, despite apparently sound reasoning from true premises, leads to an apparently self-contradictory or logically unacceptable conclusion.

New!!: Logic and Paradox · See more »

Paradoxes of material implication

The paradoxes of material implication are a group of formulae that are truths of classical logic but are intuitively problematic.

New!!: Logic and Paradoxes of material implication · See more »

Perseus Project

The Perseus Project (version 4 also known as "Perseus Hopper") is a digital library project of Tufts University, which is located in Medford and Somerville, near Boston, in the U.S. state of Massachusetts.

New!!: Logic and Perseus Project · See more »

Philo the Dialectician

Philo the Dialectician (Φίλων; fl. 300 BC) was a dialectic philosopher of the Megarian school.

New!!: Logic and Philo the Dialectician · See more »

Philosophical logic

Philosophical logic refers to those areas of philosophy in which recognized methods of logic have traditionally been used to solve or advance the discussion of philosophical problems.

New!!: Logic and Philosophical logic · See more »

Philosophical realism

Realism (in philosophy) about a given object is the view that this object exists in reality independently of our conceptual scheme.

New!!: Logic and Philosophical realism · See more »

Philosophical skepticism

Philosophical skepticism (UK spelling: scepticism; from Greek σκέψις skepsis, "inquiry") is a philosophical school of thought that questions the possibility of certainty in knowledge.

New!!: Logic and Philosophical skepticism · See more »


Philosophy (from Greek φιλοσοφία, philosophia, literally "love of wisdom") is the study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language.

New!!: Logic and Philosophy · See more »

Philosophy of mathematics

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.

New!!: Logic and Philosophy of mathematics · See more »

Philosophy of mind

Philosophy of mind is a branch of philosophy that studies the nature of the mind.

New!!: Logic and Philosophy of mind · See more »


Plato (Πλάτων Plátōn, in Classical Attic; 428/427 or 424/423 – 348/347 BC) was a philosopher in Classical Greece and the founder of the Academy in Athens, the first institution of higher learning in the Western world.

New!!: Logic and Plato · See more »

Port-Royal Logic

Port-Royal Logic, or Logique de Port-Royal, is the common name of La logique, ou l'art de penser, an important textbook on logic first published anonymously in 1662 by Antoine Arnauld and Pierre Nicole, two prominent members of the Jansenist movement, centered on Port-Royal.

New!!: Logic and Port-Royal Logic · See more »

Posterior Analytics

The Posterior Analytics (Ἀναλυτικὰ Ὕστερα; Analytica Posteriora) is a text from Aristotle's Organon that deals with demonstration, definition, and scientific knowledge.

New!!: Logic and Posterior Analytics · See more »

Potentiality and actuality

In philosophy, potentiality and actuality are principles of a dichotomy which Aristotle used to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Nicomachean Ethics and De Anima, which is about the human psyche.

New!!: Logic and Potentiality and actuality · See more »


Pragma-dialectics, or pragma-dialectical theory, developed by Frans H. van Eemeren and Rob Grootendorst (see 1984; 1992; 2004) at the University of Amsterdam, is an argumentation theory that is used to analyze and evaluate argumentation in actual practice.

New!!: Logic and Pragma-dialectics · See more »


Predicable (Lat. praedicabilis, that which may be stated or affirmed, sometimes called quinque voces or five words) is, in scholastic logic, a term applied to a classification of the possible relations in which a predicate may stand to its subject.

New!!: Logic and Predicable · See more »

Principia Mathematica

The Principia Mathematica (often abbreviated PM) is a three-volume work on the foundations of mathematics written by Alfred North Whitehead and Bertrand Russell and published in 1910, 1912, and 1913.

New!!: Logic and Principia Mathematica · See more »

Principle of bivalence

In logic, the semantic principle (or law) of bivalence states that every declarative sentence expressing a proposition (of a theory under inspection) has exactly one truth value, either true or false.

New!!: Logic and Principle of bivalence · See more »

Principle of distributivity

The principle of distributivity states that the algebraic distributive law is valid for classical logic, where both logical conjunction and logical disjunction are distributive over each other so that for any propositions A, B and C the equivalences and hold.

New!!: Logic and Principle of distributivity · See more »

Principle of explosion

The principle of explosion (Latin: ex falso (sequitur) quodlibet (EFQ), "from falsehood, anything (follows)", or ex contradictione (sequitur) quodlibet (ECQ), "from contradiction, anything (follows)"), or the principle of Pseudo-Scotus, is the law of classical logic, intuitionistic logic and similar logical systems, according to which any statement can be proven from a contradiction.

New!!: Logic and Principle of explosion · See more »

Principles of Mathematical Logic

Principles of Mathematical Logic is the 1950 American translation of the 1938 second edition of David Hilbert's and Wilhelm Ackermann's classic text Grundzüge der theoretischen Logik, on elementary mathematical logic.

New!!: Logic and Principles of Mathematical Logic · See more »

Prior Analytics

The Prior Analytics (Ἀναλυτικὰ Πρότερα; Analytica Priora) is Aristotle's work on deductive reasoning, which is known as his syllogistic.

New!!: Logic and Prior Analytics · See more »

Problem of future contingents

Future contingent propositions (or simply, future contingents) are statements about states of affairs in the future that are contingent: neither necessarily true nor necessarily false.

New!!: Logic and Problem of future contingents · See more »

Problem of multiple generality

The problem of multiple generality names a failure in traditional logic to describe certain intuitively valid inferences.

New!!: Logic and Problem of multiple generality · See more »

Programming language

A programming language is a formal language that specifies a set of instructions that can be used to produce various kinds of output.

New!!: Logic and Programming language · See more »


Prolog is a general-purpose logic programming language associated with artificial intelligence and computational linguistics.

New!!: Logic and Prolog · See more »

Proof calculus

In mathematical logic, a proof calculus or a proof system is built to prove statements.

New!!: Logic and Proof calculus · See more »

Proof theory

Proof theory is a major branchAccording to Wang (1981), pp.

New!!: Logic and Proof theory · See more »

Proof-theoretic semantics

Proof-theoretic semantics is an approach to the semantics of logic that attempts to locate the meaning of propositions and logical connectives not in terms of interpretations, as in Tarskian approaches to semantics, but in the role that the proposition or logical connective plays within the system of inference.

New!!: Logic and Proof-theoretic semantics · See more »


The term proposition has a broad use in contemporary analytic philosophy.

New!!: Logic and Proposition · See more »

Propositional calculus

Propositional calculus is a branch of logic.

New!!: Logic and Propositional calculus · See more »


Psychologism is a philosophical position, according to which psychology plays a central role in grounding or explaining some other, non-psychological type of fact or law.

New!!: Logic and Psychologism · See more »


Psychology is the science of behavior and mind, including conscious and unconscious phenomena, as well as feeling and thought.

New!!: Logic and Psychology · See more »

Qin dynasty

The Qin dynasty was the first dynasty of Imperial China, lasting from 221 to 206 BC.

New!!: Logic and Qin dynasty · See more »

Quantifier (logic)

In logic, quantification specifies the quantity of specimens in the domain of discourse that satisfy an open formula.

New!!: Logic and Quantifier (logic) · See more »

Quantum logic

In quantum mechanics, quantum logic is a set of rules for reasoning about propositions that takes the principles of quantum theory into account.

New!!: Logic and Quantum logic · See more »


Rationality is the quality or state of being rational – that is, being based on or agreeable to reason.

New!!: Logic and Rationality · See more »

Real number

In mathematics, a real number is a value of a continuous quantity that can represent a distance along a line.

New!!: Logic and Real number · See more »


Reason is the capacity for consciously making sense of things, establishing and verifying facts, applying logic, and changing or justifying practices, institutions, and beliefs based on new or existing information.

New!!: Logic and Reason · See more »

Relevance logic

Relevance logic, also called relevant logic, is a kind of non-classical logic requiring the antecedent and consequent of implications to be relevantly related.

New!!: Logic and Relevance logic · See more »


Rhetoric is the art of discourse, wherein a writer or speaker strives to inform, persuade, or motivate particular audiences in specific situations.

New!!: Logic and Rhetoric · See more »

Rival conceptions of logic

The history of logic as a subject has been characterised by many disputes over what the topic deals with, and the main article 'Logic' has as a result been hesitant to commit to a particular definition of logic.

New!!: Logic and Rival conceptions of logic · See more »

Robert Brandom

Robert Boyce Brandom (born March 13, 1950) is an American philosopher who teaches at the University of Pittsburgh.

New!!: Logic and Robert Brandom · See more »


Routledge is a British multinational publisher.

New!!: Logic and Routledge · See more »

Rule induction

Rule induction is an area of machine learning in which formal rules are extracted from a set of observations.

New!!: Logic and Rule induction · See more »

Rule of inference

In logic, a rule of inference, inference rule or transformation rule is a logical form consisting of a function which takes premises, analyzes their syntax, and returns a conclusion (or conclusions).

New!!: Logic and Rule of inference · See more »

Russell's paradox

In the foundations of mathematics, Russell's paradox (also known as Russell's antinomy), discovered by Bertrand Russell in 1901, showed that some attempted formalizations of the naïve set theory created by Georg Cantor led to a contradiction.

New!!: Logic and Russell's paradox · See more »

Saul Kripke

Saul Aaron Kripke (born November 13, 1940) is an American philosopher and logician.

New!!: Logic and Saul Kripke · See more »


Scholasticism is a method of critical thought which dominated teaching by the academics ("scholastics", or "schoolmen") of medieval universities in Europe from about 1100 to 1700, and a program of employing that method in articulating and defending dogma in an increasingly pluralistic context.

New!!: Logic and Scholasticism · See more »

Second-order logic

In logic and mathematics second-order logic is an extension of first-order logic, which itself is an extension of propositional logic.

New!!: Logic and Second-order logic · See more »

Semantic theory of truth

A semantic theory of truth is a theory of truth in the philosophy of language which holds that truth is a property of sentences.

New!!: Logic and Semantic theory of truth · See more »


Semantics (from σημαντικός sēmantikós, "significant") is the linguistic and philosophical study of meaning, in language, programming languages, formal logics, and semiotics.

New!!: Logic and Semantics · See more »

Semantics (computer science)

In programming language theory, semantics is the field concerned with the rigorous mathematical study of the meaning of programming languages.

New!!: Logic and Semantics (computer science) · See more »

Set theory

Set theory is a branch of mathematical logic that studies sets, which informally are collections of objects.

New!!: Logic and Set theory · See more »

Sextus Empiricus

Sextus Empiricus (Σέξτος Ἐμπειρικός; c. 160 – c. 210 CE, n.b., dates uncertain), was a physician and philosopher, who likely lived in Alexandria, Rome, or Athens.

New!!: Logic and Sextus Empiricus · See more »


In mathematical logic, a logical system has the soundness property if and only if every formula that can be proved in the system is logically valid with respect to the semantics of the system.

New!!: Logic and Soundness · See more »

Southern Illinois University Press

Southern Illinois University Press or SIU Press, founded in 1956, is a university press located in Carbondale, Illinois, owned and operated by Southern Illinois University.

New!!: Logic and Southern Illinois University Press · See more »

Stanford Encyclopedia of Philosophy

The Stanford Encyclopedia of Philosophy (SEP) combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users.

New!!: Logic and Stanford Encyclopedia of Philosophy · See more »

Stephen Toulmin

Stephen Edelston Toulmin (25 March 1922 – 4 December 2009) was a British philosopher, author, and educator.

New!!: Logic and Stephen Toulmin · See more »

Stewart Shapiro

Stewart Shapiro (born 1951) is O'Donnell Professor of Philosophy at the Ohio State University.

New!!: Logic and Stewart Shapiro · See more »

Stoic logic

Stoic logic is the system of propositional logic developed by the Stoic philosophers in ancient Greece.

New!!: Logic and Stoic logic · See more »


Stoicism is a school of Hellenistic philosophy founded by Zeno of Citium in Athens in the early 3rd century BC.

New!!: Logic and Stoicism · See more »

Strict conditional

In logic, a strict conditional is a conditional governed by a modal operator, that is, a logical connective of modal logic.

New!!: Logic and Strict conditional · See more »

Structural proof theory

In mathematical logic, structural proof theory is the subdiscipline of proof theory that studies proof calculi that support a notion of analytic proof.

New!!: Logic and Structural proof theory · See more »

Structure (mathematical logic)

In universal algebra and in model theory, a structure consists of a set along with a collection of finitary operations and relations that are defined on it.

New!!: Logic and Structure (mathematical logic) · See more »

Sum of Logic

The Summa Logicae ("Sum of Logic") is a textbook on logic by William of Ockham.

New!!: Logic and Sum of Logic · See more »


In philosophical logic, supervaluationism is a semantics for dealing with irreferential singular terms and vagueness.

New!!: Logic and Supervaluationism · See more »

Supposition theory

Supposition theory was a branch of medieval logic that was probably aimed at giving accounts of issues similar to modern accounts of reference, plurality, tense, and modality, within an Aristotelian context.

New!!: Logic and Supposition theory · See more »

Susan Haack

Susan Haack (born 1945) is Distinguished Professor in the Humanities, Cooper Senior Scholar in Arts and Sciences, Professor of Philosophy, and Professor of Law at the University of Miami.

New!!: Logic and Susan Haack · See more »


A syllogism (συλλογισμός syllogismos, "conclusion, inference") is a kind of logical argument that applies deductive reasoning to arrive at a conclusion based on two or more propositions that are asserted or assumed to be true.

New!!: Logic and Syllogism · See more »

Tautology (logic)

In logic, a tautology (from the Greek word ταυτολογία) is a formula or assertion that is true in every possible interpretation.

New!!: Logic and Tautology (logic) · See more »

Temporal logic

In logic, temporal logic is any system of rules and symbolism for representing, and reasoning about, propositions qualified in terms of time.

New!!: Logic and Temporal logic · See more »

Term logic

In philosophy, term logic, also known as traditional logic, syllogistic logic or Aristotelian logic, is a loose name for an approach to logic that began with Aristotle and that was dominant until the advent of modern predicate logic in the late nineteenth century.

New!!: Logic and Term logic · See more »


Terminology is the study of terms and their use.

New!!: Logic and Terminology · See more »


The tetralemma is a figure that features prominently in the logic of India.

New!!: Logic and Tetralemma · See more »

The Gay Science

The Gay Science (Die fröhliche Wissenschaft) or The Joyful Wisdom is a book by Friedrich Nietzsche, first published in 1882 and followed by a second edition, which was published after the completion of Thus Spoke Zarathustra and Beyond Good and Evil, in 1887.

New!!: Logic and The Gay Science · See more »

The Laws of Thought

An Investigation of the Laws of Thought on Which are Founded the Mathematical Theories of Logic and Probabilities by George Boole, published in 1854, is the second of Boole's two monographs on algebraic logic.

New!!: Logic and The Laws of Thought · See more »

Three-valued logic

In logic, a three-valued logic (also trinary logic, trivalent, ternary, or trilean, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.

New!!: Logic and Three-valued logic · See more »

Topics (Aristotle)

The Topics (Τοπικά; Topica) is the name given to one of Aristotle's six works on logic collectively known as the Organon: The Topics constitutes Aristotle's treatise on the art of dialectic—the invention and discovery of arguments in which the propositions rest upon commonly held opinions or endoxa (ἔνδοξα in Greek).

New!!: Logic and Topics (Aristotle) · See more »


Truth is most often used to mean being in accord with fact or reality, or fidelity to an original or standard.

New!!: Logic and Truth · See more »

Truth value

In logic and mathematics, a truth value, sometimes called a logical value, is a value indicating the relation of a proposition to truth.

New!!: Logic and Truth value · See more »

Turing degree

In computer science and mathematical logic the Turing degree (named after Alan Turing) or degree of unsolvability of a set of natural numbers measures the level of algorithmic unsolvability of the set.

New!!: Logic and Turing degree · See more »

Universal logic

Universal logic is the field of logic that studies the common features of all logical systems, aiming to be to logic what universal algebra is to algebra.

New!!: Logic and Universal logic · See more »

Universal quantification

In predicate logic, a universal quantification is a type of quantifier, a logical constant which is interpreted as "given any" or "for all".

New!!: Logic and Universal quantification · See more »

University of California Press

University of California Press, otherwise known as UC Press, is a publishing house associated with the University of California that engages in academic publishing.

New!!: Logic and University of California Press · See more »


In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.

New!!: Logic and Validity · See more »

Vector logic

Vector logicMizraji, E. (1992).

New!!: Logic and Vector logic · See more »

Walter Burley

Walter Burley (or Burleigh) (c. 1275–1344/5) was a medieval English scholastic philosopher and logician with at least 50 works attributed to him.

New!!: Logic and Walter Burley · See more »

Wilfrid Hodges

Wilfrid Augustine Hodges, FBA (born 27 May 1941) is a British mathematician, known for his work in model theory.

New!!: Logic and Wilfrid Hodges · See more »

Wilfrid Sellars

Wilfrid Stalker Sellars (May 20, 1912 – July 2, 1989) was an American philosopher and prominent developer of critical realism, who "revolutionized both the content and the method of philosophy in the United States".

New!!: Logic and Wilfrid Sellars · See more »

Wilhelm Ackermann

Wilhelm Friedrich Ackermann (29 March 1896 – 24 December 1962) was a German mathematician best known for the Ackermann function, an important example in the theory of computation.

New!!: Logic and Wilhelm Ackermann · See more »

Willard Van Orman Quine

Willard Van Orman Quine (known to intimates as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth century." From 1930 until his death 70 years later, Quine was continually affiliated with Harvard University in one way or another, first as a student, then as a professor of philosophy and a teacher of logic and set theory, and finally as a professor emeritus who published or revised several books in retirement.

New!!: Logic and Willard Van Orman Quine · See more »

William Kneale

William Calvert Kneale (22 June 1906 – 24 June 1990) was an English logician best known for his 1962 book The Development of Logic, a history of logic from its beginnings in Ancient Greece written with his wife Martha.

New!!: Logic and William Kneale · See more »

William of Ockham

William of Ockham (also Occam, from Gulielmus Occamus; 1287 – 1347) was an English Franciscan friar and scholastic philosopher and theologian, who is believed to have been born in Ockham, a small village in Surrey.

New!!: Logic and William of Ockham · See more »

William Wallace (philosopher)

William Wallace (11 May 1844 – 18 February 1897) was a Scottish philosopher and academic who became fellow of Merton College and White's Professor of Moral Philosophy at Oxford University.

New!!: Logic and William Wallace (philosopher) · See more »

Redirects here:

Classical two-valued logic, Compound proposition, DefinitionOfLogic, Formal symbolic logic, Logic of mathematics, Logic/alternate-start, Logical, Logical rules, Logically, Logician, Logico, Logics, Logicus, Logika, Logike, Lógica, Material logic, Types of logic.


[1] https://en.wikipedia.org/wiki/Logic

Hey! We are on Facebook now! »