There are many reasons people use tautology in both everyday discussion and poetry, research papers, prose, and song lyrics. Needless repetition of the same sense in different words. Dictionary grammar blog school scrabble thesaurus translator quiz more resources more from collins. Pdf on mar 1, 1971, joseph agassi and others published tautology and testability in economics find, read and cite all the research you. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Basically, find the truth value of each side then plug in a biconditional sign to see if it works. In pin number the word number is a tautology because a pin is always a number. Philosophy a compound propositional form all of whose instances are true. If their biconditional is a tautology, then theyre logically equivalent. A less abstract example is the ball is all green, or the ball is not all green.
In logic, it can be a universal truth that is always valid. It outlines current philosophical problems and issues, as well as an overview of. In logic, a tautology is a formula or assertion that is true in every possible interpretation. Tautology rhetorical devices literature ultius glossary. Wikipedia has this to say about a logical tautology.
In manyvalued logic, a tautology is a formula which in any set from an accepted universal system of values for variables retains the same distinctive value. D is a tautology b d b b v d d f a tautology will never be false, so if we plug in a value of f for the main connective and get a coherent truth assignment for b and d, we know that the sentence can be false, and so cannot be a tautology. Russells moral philosophy stanford encyclopedia of. By including all possibilities the statement must inherently be true. Mar 01, 2020 tautology countable and uncountable, plural tautologies uncountable redundant use of words, a pleonasm, an unnecessary and tedious repetition. Logic and the philosophy of science princeton university.
Russells moral philosophy first published mon dec 17, 2007. Classical logic stanford encyclopedia of philosophy. It refers to a redundant logic wherein a principle is restated or is evident in its expression. If you are given any statement or argument, you can determine if it is a tautology by constructing a truth table for the statement and looking at. Definition of tautology from our glossary of english linguistic and grammatical terms containing explanations and crossreferences to other relevant english grammar terms.
This might involve, for example, taking the presence of an effect to argue for the presence of a cause, which is then claimed to bring. A statement that is always true, especially a truthfunctional expression that takes the value of true for all combinations of values of its components. A tautology in firstorder logic is a sentence that can be obtained by taking a tautology of propositional logic and uniformly replacing each propositional variable by a firstorder formula one formula per propositional variable. Tautology definition of tautology by the free dictionary. The expression raze to the ground is a tautology, since the word raze includes the notion to the ground. Any opinions in the examples do not represent the opinion of the cambridge dictionary editors or of cambridge university press or its licensors. The mathematical study of logic, and philosophical thought about logic, are two of the oldest. Tautology definition of tautology by merriamwebster. Tautology is the repetitive use of phrases or words that have similar meanings. The opposite of a tautology is a contradiction, a formula which is always false. This type of tautology is used in proofs of independence. Tautologies are necessarily true, contradictions necessarily false, and so one might ex. Does the phrase vacuous tautology have specific meaning. Learn the definition and increase your comprehension by reading the word tautology in a sentence.
And to say so is not to engage in tautology, which i think you were referring to, andrew, when you made that remark about philosophy classes. Tautological statement synonyms, tautological statement pronunciation, tautological statement translation, english dictionary definition of tautological statement. The word tautology is derived from the greek word tauto, meaning the same, and logos, meaning a word or an idea. Meaning of tautology in a sentence words in sentences. A tautology is a formula which is always true that is, it is true for every assignment of truth values to its simple components. Tautology, in logic, a statement so framed that it cannot be denied without inconsistency. English chinese french german hindi italian portuguese spanish.
See priest 2006a for a description of how being the best reasoningguiding logic could make a logic the one right logic. This might involve, for example, taking the presence of an effect to argue for the presence of. An example of this type of tautology is the law of the excluded middle. A statement that is always true by a virtue of its components. Anaphora is the repetition of a certain phrase at the beginning of successive sentences or phrases. Philosophy a compound propositional form all of whose instances are true, as a or not a. Tautology definition, needless repetition of an idea, especially in words other than those of the immediate context, without imparting additional force or clearness, as in widow woman. Tautology is nothing but repeated use of words or phrases that have a similar meaning. The word is sometimes used for satire or insult, for example, see the second usage example below. Often, repetition is meaningful or poetic and may emphasize an important aspect. For this reason, a tautology is usually undesirable, as it can make you sound wordier than you need to be, and make you appear foolish. Tautology is the repetitive use of words or phrases which have similar meanings to one another. Tautology is the use of different words to say the same thing twice in the same. A tautology is a repetition, a redundancy, saying the same thing more than once where no additional information is provided.
A tautology is a single proposition, not an argument, that is true due to its form alone therefore true in any model. Its only a tautology is you pretend life and niches dont have distinguishable properties and that a niche cant be populated. If assuming a false sentence prevents us from arriving at any coherent truth. For examples of meaningful repetition, consider anaphora and epistrophe. An expression that features tautology a statement that is true for all values of its variables. A tautology in logic is a formula that is always true on any valuation or. Tautology is a type of logic construct that can be applied in it. Pdf tautology and testability in economics researchgate. From longman dictionary of contemporary english tautology tau.
The same thing happens with pdf format, pin number and upc code. Whatever you have to say, whatever you do, avoid tautology. Tautology meaning in the cambridge english dictionary. Anthropological term of polynesian origin applied to persons or things with which contacts are forbidden under severe social and religious penalties. Examples of tautology a tautology is an expression or phrase that says the same thing twice, just in a different way. The philosopher ludwig wittgenstein first applied the term to redundancies of. A tautology often involves just a few words in a sentence that have the same meaning, or in which one word is part of the.
Tautology definition and meaning collins english dictionary. A grammatical tautology refers to an idea repeated. In simple words, it is expressing the same thing, an idea, or saying, two or more times. Essentially, a tautology expresses the same thing, idea, or saying repeatedly. Here is a truth table for the tautology priest considered. Thus, all humans are mammals is held to assert with regard to anything whatsoever that either it is not a human or it is a mammal. Tautology and pleonasm are not consistently differentiated in literature. Mar 10, 2019 at the risk of being redundant and repetitive, and redundant, let me say that tautology is the last thing children need from their parents, especially when they are in trouble. It would be a tautology for which no row of the truth table has all of the premises true.
In literary criticism and rhetoric, a tautology is a statement which repeats an idea, using nearsynonymous morphemes, words or phrases, saying the same thing twice. This might be the criteria for a vacuous tautology. Tautology is an unwanted repetition, but not all repetition is pointless. Jan 01, 2011 a statement or conclusion that involves. A tautology is, to define it in a tautological manner, to repeat the same thing twice in different words. At least thats what the n originally stood for if the term pin evolved to include letters someday then pin number would. Either well get in trouble, or we wont is a logical tautology. That classical logic has been given as the answer to which logic ought to guide reasoning is not unexpected. For this reason, classical logic has often been called the one right logic. Tautology definition is needless repetition of an idea, statement, or word. But that universal truth follows not from any facts noted about real humans but only from the actual use of. Tautology article about tautology by the free dictionary.
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