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. Anthropological term of polynesian origin applied to persons or things with which contacts are forbidden under severe social and religious penalties. Whatever you have to say, whatever you do, avoid tautology. 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. Philosophy a compound propositional form all of whose instances are true, as a or not a. At least thats what the n originally stood for if the term pin evolved to include letters someday then pin number would. This type of tautology is used in proofs of independence. That classical logic has been given as the answer to which logic ought to guide reasoning is not unexpected. Tautology is nothing but repeated use of words or phrases that have a similar meaning.
Tautology is a type of logic construct that can be applied in it. Tautology article about tautology by the free dictionary. Tautology is the repetitive use of phrases or words that have similar meanings. Tautology and pleonasm are not consistently differentiated in literature. Any opinions in the examples do not represent the opinion of the cambridge dictionary editors or of cambridge university press or its licensors. 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. Needless repetition of the same sense in different words. But that universal truth follows not from any facts noted about real humans but only from the actual use of. 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. A tautology is a repetition, a redundancy, saying the same thing more than once where no additional information is provided.
Nonvacuous tautologies would have at least one row where the premises are all true, such as the tautology, p implies p. Wikipedia has this to say about a logical tautology. A grammatical tautology refers to an idea repeated. 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. Logic and the philosophy of science princeton university. Tautological 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. It outlines current philosophical problems and issues, as well as an overview of.
The philosopher ludwig wittgenstein first applied the term to redundancies of. Definition of tautology from our glossary of english linguistic and grammatical terms containing explanations and crossreferences to other relevant english grammar terms. There are many reasons people use tautology in both everyday discussion and poetry, research papers, prose, and song lyrics. Its only a tautology is you pretend life and niches dont have distinguishable properties and that a niche cant be populated. By including all possibilities the statement must inherently be true. For examples of meaningful repetition, consider anaphora and epistrophe. 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. Tautology definition and meaning collins english dictionary. In logic, a tautology is a formula or assertion that is true in every possible interpretation. Tautology definition is needless repetition of an idea, statement, or word. Often, repetition is meaningful or poetic and may emphasize an important aspect. In simple words, it is expressing the same thing, an idea, or saying, two or more times. Tautology meaning in the cambridge english dictionary.
A tautology in logic is a formula that is always true on any valuation or. Mar 01, 2020 tautology countable and uncountable, plural tautologies uncountable redundant use of words, a pleonasm, an unnecessary and tedious repetition. Tautology is an unwanted repetition, but not all repetition is pointless. The mathematical study of logic, and philosophical thought about logic, are two of the oldest.
Tautology, in logic, a statement so framed that it cannot be denied without inconsistency. Anaphora is the repetition of a certain phrase at the beginning of successive sentences or phrases. In logic, it can be a universal truth that is always valid. Tautological statement synonyms, tautological statement pronunciation, tautological statement translation, english dictionary definition of tautological statement. Pdf on mar 1, 1971, joseph agassi and others published tautology and testability in economics find, read and cite all the research you. 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. A statement that is always true, especially a truthfunctional expression that takes the value of true for all combinations of values of its components.
Tautology definition of tautology by the free dictionary. Here is a truth table for the tautology priest considered. Russells moral philosophy first published mon dec 17, 2007. English chinese french german hindi italian portuguese spanish. Essentially, a tautology expresses the same thing, idea, or saying repeatedly. Tautology rhetorical devices literature ultius glossary. Tautologies are necessarily true, contradictions necessarily false, and so one might ex. It would be a tautology for which no row of the truth table has all of the premises true. It refers to a redundant logic wherein a principle is restated or is evident in its expression. The primitive belief in taboos, affording as it does religious sanctions for moral prohibitions, is of great ethical significance and has even been considered by some to be the origin of morality and ethics.
Meaning of tautology in a sentence words in sentences. The opposite of a tautology is a contradiction, a formula which is always false. 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. In pin number the word number is a tautology because a pin is always a number. 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. A statement that is always true by a virtue of its components. This might involve, for example, taking the presence of an effect to argue for the presence of. The same thing happens with pdf format, pin number and upc code. An example of this type of tautology is the law of the excluded middle. Learn the definition and increase your comprehension by reading the word tautology in a sentence. If assuming a false sentence prevents us from arriving at any coherent truth. Tautology is the use of different words to say the same thing twice in the same. Dictionary grammar blog school scrabble thesaurus translator quiz more resources more from collins. A tautology is a single proposition, not an argument, that is true due to its form alone therefore true in any model.
An expression that features tautology a statement that is true for all values of its variables. A less abstract example is the ball is all green, or the ball is not all green. 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. Jan 01, 2011 a statement or conclusion that involves. Examples of tautology a tautology is an expression or phrase that says the same thing twice, just in a different way. The expression raze to the ground is a tautology, since the word raze includes the notion to the ground.
Basically, find the truth value of each side then plug in a biconditional sign to see if it works. 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. The word is sometimes used for satire or insult, for example, see the second usage example below. Classical logic stanford encyclopedia of philosophy. In this article well give you some easy and funny tautology examples that you might be using knowingly or unknowingly. A tautology is a formula which is always true that is, it is true for every assignment of truth values to its simple components. If their biconditional is a tautology, then theyre logically equivalent. For this reason, classical logic has often been called the one right logic. This might be the criteria for a vacuous tautology. Using tautologies and contradictions semantics archive. Philosophy a compound propositional form all of whose instances are true. Nov 18, 2010 if it is not a tautology, then what is it about laycocks two sentences that is not tautological according to the definition of tautology in logic.
Either well get in trouble, or we wont is a logical tautology. The word tautology is derived from the greek word tauto, meaning the same, and logos, meaning a word or an idea. 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. 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. A tautology is, to define it in a tautological manner, to repeat the same thing twice in different words.
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