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Term Logic
In logic and formal semantics, term logic, also known as traditional logic, syllogistic logic or Aristotelian logic, is a loose name for an approach to formal logic that began with Aristotle and was developed further in ancient history mostly by his followers, the Peripatetics. It was revived after the third century CE by Porphyry's Isagoge. Term logic revived in medieval times, first in Islamic logic by Alpharabius in the tenth century, and later in Christian Europe in the twelfth century with the advent of new logic, remaining dominant until the advent of predicate logic in the late nineteenth century. However, even if eclipsed by newer logical systems, term logic still plays a significant role in the study of logic. Rather than radically breaking with term logic, modern logics typically expand it. Aristotle's system Aristotle's logical work is collected in the six texts that are collectively known as the '' Organon''. Two of these texts in particular, namely th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure of arguments alone, independent of their topic and content. Informal logic is associated with informal fallacies, critical thinking, and argumentation theory. Informal logic examines arguments expressed in natural language whereas formal logic uses formal language. When used as a countable noun, the term "a logic" refers to a specific logical formal system that articulates a proof system. Logic plays a central role in many fields, such as philosophy, mathematics, computer science, and linguistics. Logic studies arguments, which consist of a set of premises that leads to a conclusion. An example is the argument from the premises "it's Sunday" and "if it's Sunday then I don't have to work" leading to the conclusion "I don't have to wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Lukasiewicz
Jan, JaN or JAN may refer to: Acronyms * Jackson, Mississippi (Amtrak station), US, Amtrak station code JAN * Jackson-Evers International Airport, Mississippi, US, IATA code * Jabhat al-Nusra (JaN), a Syrian militant group * Japanese Article Number, a barcode standard compatible with EAN * Japanese Accepted Name, a Japanese nonproprietary drug name * Job Accommodation Network, US, for people with disabilities * ''Joint Army-Navy'', US standards for electronic color codes, etc. * ''Journal of Advanced Nursing'' Personal name * Jan (name), male variant of ''John'', female shortened form of ''Janet'' and ''Janice'' * Jan (Persian name), Persian word meaning 'life', 'soul', 'dear'; also used as a name * Ran (surname), romanized from Mandarin as Jan in Wade–Giles * Ján, Slovak name Other uses * January, as an abbreviation for the first month of the year in the Gregorian calendar * Jan (cards), a term in some card games when a player loses without taking any tricks or scoring a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subject (grammar)
A subject is one of the two main parts of a Sentence (linguistics), sentence (the other being the Predicate (grammar), predicate, which modifies the subject). For the simple Sentence (linguistics), sentence ''John runs'', ''John'' is the subject, a person or thing about whom the statement is made. Traditionally the subject is the word or phrase which controls the verb in the clause, that is to say with which the verb Agreement (linguistics), agrees (''John is'' but ''John and Mary are''). If there is no verb, as in ''Nicola what an idiot!'', or if the verb has a different subject, as in ''John I can't stand him!'', then 'John' is not considered to be the grammatical subject, but can be described as the ''Topic and comment, topic'' of the sentence. While these definitions apply to simple English sentences, defining the subject is more difficult in more complex sentences and languages. For example, in the sentence ''It is difficult to learn French'', the subject seems to be the wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predicate (grammar)
The term predicate is used in two ways in linguistics and its subfields. The first defines a predicate as everything in a standard declarative sentence except the subject (grammar), subject, and the other defines it as only the main content verb or associated predicative expression of a clause. Thus, by the first definition, the predicate of the sentence ''Frank likes cake'' is ''likes cake'', while by the second definition, it is only the content verb ''likes'', and ''Frank'' and ''cake'' are the argument (linguistics), arguments of this predicate. The conflict between these two definitions can lead to confusion. Syntax Traditional grammar The notion of a predicate in traditional grammar traces back to Aristotelian logic. A predicate is seen as a property that a subject has or is characterized by. A predicate is therefore an expression that can be ''true of'' something. Thus, the expression "is moving" is true of anything that is moving. This classical understanding of pred ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Part Of Speech
In grammar, a part of speech or part-of-speech ( abbreviated as POS or PoS, also known as word class or grammatical category) is a category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are assigned to the same part of speech generally display similar syntactic behavior (they play similar roles within the grammatical structure of sentences), sometimes similar morphological behavior in that they undergo inflection for similar properties and even similar semantic behavior. Commonly listed English parts of speech are noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, numeral, article, and determiner. Other terms than ''part of speech''—particularly in modern linguistic classifications, which often make more precise distinctions than the traditional scheme does—include word class, lexical class, and lexical category. Some authors restrict the term ''lexical category'' to refer only to a par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reasoning
Reason is the capacity of consciously applying logic by drawing valid conclusions from new or existing information, with the aim of seeking the truth. It is associated with such characteristically human activities as philosophy, religion, science, language, mathematics, and art, and is normally considered to be a distinguishing ability possessed by humans. Reason is sometimes referred to as rationality. Reasoning involves using more-or-less rational processes of thinking and cognition to extrapolate from one's existing knowledge to generate new knowledge, and involves the use of one's intellect. The field of studies the ways in which humans can use formal reasoning to produce logically valid arguments and true conclusions. Reasoning may be subdivided into forms of logical reasoning, such as deductive reasoning, inductive reasoning, and abductive reasoning. Aristotle drew a distinction between logical discursive reasoning (reason proper), and intuitive reasoning, in whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbol (formal)
A logical symbol is a fundamental concept in logic, type–token distinction, tokens of which may be marks or a configuration of marks which form a particular pattern. Although the term ''symbol'' in common use sometimes refers to the idea being symbolized, and at other times to the marks on a piece of paper or chalkboard which are being used to express that idea; in the formal languages studied in mathematics and logic, the term ''symbol'' refers to the idea, and the marks are considered to be a type-token distinction, token instance of the symbol. In logic, symbols build literal utility to illustrate ideas. Overview Symbols of a formal language need not be symbols ''of'' anything. For instance there are logical constants which do not refer to any idea, but rather serve as a form of punctuation in the language (e.g. parentheses). Symbols of a formal language must be capable of being specified without any reference to any interpretation (logic), interpretation of them. A symbol o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propositions
A proposition is a statement that can be either true or false. It is a central concept in the philosophy of language, semantics, logic, and related fields. Propositions are the object s denoted by declarative sentences; for example, "The sky is blue" expresses the proposition that the sky is blue. Unlike sentences, propositions are not linguistic expressions, so the English sentence "Snow is white" and the German "Schnee ist weiß" denote the same proposition. Propositions also serve as the objects of belief and other propositional attitudes, such as when someone believes that the sky is blue. Formally, propositions are often modeled as functions which map a possible world to a truth value. For instance, the proposition that the sky is blue can be modeled as a function which would return the truth value T if given the actual world as input, but would return F if given some alternate world where the sky is green. However, a number of alternative formalizations have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formal System
A formal system is an abstract structure and formalization of an axiomatic system used for deducing, using rules of inference, theorems from axioms. In 1921, David Hilbert proposed to use formal systems as the foundation of knowledge in mathematics. The term ''formalism'' is sometimes a rough synonym for ''formal system'', but it also refers to a given style of notation, for example, Paul Dirac's bra–ket notation. Concepts A formal system has the following: * Formal language, which is a set of well-formed formulas, which are strings of symbols from an alphabet, formed by a formal grammar (consisting of production rules or formation rules). * Deductive system, deductive apparatus, or proof system, which has rules of inference that take axioms and infers theorems, both of which are part of the formal language. A formal system is said to be recursive (i.e. effective) or recursively enumerable if the set of axioms and the set of inference rules are decidable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Categories (Aristotle)
The ''Categories'' (; or ) is a text from Aristotle's '' Organon'' that enumerates all the possible kinds of things that can be the subject or the predicate of a proposition. They are "perhaps the single most heavily discussed of all Aristotelian notions". The work is brief enough to be divided not into books, as is usual with Aristotle's works, but into fifteen chapters. The ''Categories'' places every object of human apprehension under one of ten categories (known to medieval writers as the Latin term ). Aristotle intended them to enumerate everything that can be expressed without composition or structure, thus anything that can be either the subject or the predicate of a proposition. The text The antepraedicamenta The text begins with an explication of what Aristotle means by " synonymous", or univocal words, what is meant by "homonymous", or equivocal words, and what is meant by " paronymous", or denominative (sometimes translated "derivative") words. It then divi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premise
A premise or premiss is a proposition—a true or false declarative statement—used in an argument to prove the truth of another proposition called the conclusion. Arguments consist of a set of premises and a conclusion. An argument is meaningful for its conclusion only when all of its premises are true. If one or more premises are false, the argument says nothing about whether the conclusion is true or false. For instance, a false premise on its own does not justify rejecting an argument's conclusion; to assume otherwise is a logical fallacy called denying the antecedent. One way to prove that a proposition is false is to formulate a sound argument with a conclusion that negates that proposition. An argument is sound and its conclusion logically follows (it is true) if and only if the argument is valid ''and'' its premises are true. An argument is valid if and only if it is the case that whenever the premises are all true, the conclusion must also be true. If there exis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syllogisms
A syllogism (, ''syllogismos'', 'conclusion, inference') is a kind of logical argument that applies deductive reasoning to arrive at a conclusion based on two propositions that are asserted or assumed to be true. In its earliest form (defined by Aristotle in his 350 BC book '' Prior Analytics''), a deductive syllogism arises when two true premises (propositions or statements) validly imply a conclusion, or the main point that the argument aims to get across. For example, knowing that all men are mortal (major premise), and that Socrates is a man (minor premise), we may validly conclude that Socrates is mortal. Syllogistic arguments are usually represented in a three-line form: All men are mortal. Socrates is a man. Therefore, Socrates is mortal.In antiquity, two rival syllogistic theories existed: Aristotelian syllogism and Stoic syllogism. From the Middle Ages onwards, ''categorical syllogism'' and ''syllogism'' were usually used interchangeably. This article is concerne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
