Linguistics

In linguistics, displacement is the capability of language to communicate about things that are not immediately present (spatially or temporally); i.e., things that are either not here or are not here now.

In 1960, Charles F. Hockett proposed displacement as one of 13 design features of language that distinguish human language from animal communication systems (ACSs):

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 work." Premises and conclusions express propositions or claims that can be true or false. An important feature of propositions is their internal structure. For example, complex propositions are made up of simpler propositions linked by logical vocabulary like ${\displaystyle \land }$ (and) or ${\displaystyle \to }$ (if...then). Simple propositions also have parts, like "Sunday" or "work" in the example. The truth of a proposition usually depends on the meanings of all of its parts. However, this is not the case for logically true propositions. They are true only because of their logical structure independent of the specific meanings of the individual parts.

In linguistics, the comparative method is a technique for studying the development of languages by performing a feature-by-feature comparison of two or more languages with common descent from a shared ancestor and then extrapolating backwards to infer the properties of that ancestor. The comparative method may be contrasted with the method of internal reconstruction in which the internal development of a single language is inferred by the analysis of features within that language. Ordinarily, both methods are used together to reconstruct prehistoric phases of languages; to fill in gaps in the historical record of a language; to discover the development of phonological, morphological and other linguistic systems and to confirm or to refute hypothesised relationships between languages.

The comparative method emerged in the early 19th century with the birth of Indo-European studies, then took a definite scientific approach with the works of the Neogrammarians in the late 19th–early 20th century. Key contributions were made by the Danish scholars Rasmus Rask (1787–1832) and Karl Verner (1846–1896), and the German scholar Jacob Grimm (1785–1863). The first linguist to offer reconstructed forms from a proto-language was August Schleicher (1821–1868) in his Compendium der vergleichenden Grammatik der indogermanischen Sprachen, originally published in 1861. Here is Schleicher's explanation of why he offered reconstructed forms:

Glottolog is an open-access online bibliographic database of the world's languages. In addition to listing linguistic materials (grammars, articles, dictionaries) describing individual languages, the database also contains the most up-to-date language affiliations based on the work of expert linguists.

Glottolog was first developed and maintained at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and between 2015 and 2020 at the Max Planck Institute of Geoanthropology in Jena, Germany. Its main curators include Harald Hammarström and Martin Haspelmath.

In linguistics and the philosophy of language, a locutionary act is the performance of an utterance, and is one of the types of force, in addition to illocutionary act and perlocutionary act, typically cited in Speech Act Theory. Speech Act Theory is a subfield of pragmatics that explores how words and sentences are not only used to present information, but also to perform actions. As an utterance, a locutionary act is considered a performative, in which both the audience and the speaker must trust certain conditions about the speech act. These conditions are called felicity conditions and are divided into three different categories: the essential condition, the sincerity condition, and the preparatory condition.

The term equally refers to the surface meaning of an utterance because, according to J. L. Austin's posthumous How To Do Things With Words, a speech act should be analysed as a locutionary act (i.e. the actual utterance and its ostensible meaning, comprising phonetic, phatic, and rhetic acts corresponding to the verbal, syntactic, and semantic aspects of any meaningful utterance), as well as an illocutionary act (the semantic 'illocutionary force' of the utterance, thus its real, intended meaning), and in certain cases a further perlocutionary act (i.e. its actual effect, whether intended or not).

The concept of illocutionary acts was introduced into linguistics by the philosopher J. L. Austin in his investigation of the various aspects of speech acts. In his framework, locution is what was said and meant, illocution is what was done, and perlocution is what happened as a result.

When somebody says "Is there any salt?" at the dinner table, the illocutionary act is a request: "please give me some salt" even though the locutionary act (the literal sentence) was to ask a question about the presence of salt. The perlocutionary act (the actual effect), might be to cause somebody to pass the salt.

In linguistic pragmatics, the term metalocutionary act is sometimes used for a speech act that refers to the forms and functions of the discourse itself rather than continuing the substantive development of the discourse.

The term metalocutionary act originated as metalocution (Gibbon 1976, 1983) in functional descriptions of intonation in English and German, by analogy with locution (locutionary act), illocution (illocutionary act) and perlocution (perlocutionary act) in speech act theory. The term metalocutionary act has developed a more general meaning and may include, for example, quotation acts and comments on preceding speech acts.

In the philosophy of language and linguistics, a speech act is an utterance considered as an instance of action in a social context rather than as the mere expression of a proposition. To say "I resign", "I apologise" or "You're fired" is, in suitable circumstances, to perform the very act of resigning, apologising or dismissing, not simply to describe it. Speech-act theory therefore treats speaking a language as a kind of rule-governed social behaviour in which people make claims, issue orders, ask questions, make promises and so on by means of utterances.

Following J. L. Austin and John R. Searle, many accounts distinguish at least three levels of act in ordinary utterances: the locutionary act of producing a meaningful expression, the illocutionary act performed in saying something (such as asserting, warning, requesting or promising), and the perlocutionary act consisting in its further effects on an audience, such as persuading, amusing or alarming them. Later work has added notions such as metalocutionary acts, which organise or comment on the discourse itself, and has analysed performative utterances and indirect speech acts, in which one kind of act is performed by way of another.

Alexander Bain (11 June 1818 – 18 September 1903) was a Scottish philosopher and educationalist in the British school of empiricism and a prominent and innovative figure in the fields of psychology, linguistics, logic, moral philosophy and education reform. He founded Mind, the first ever journal of psychology and analytical philosophy, and was the leading figure in establishing and applying the scientific method to psychology. Bain was the inaugural Regius Chair in Logic and Professor of Logic at the University of Aberdeen, where he also held Professorships in Moral Philosophy and English Literature and was twice elected Lord Rector of the University of Aberdeen.

A pun, also known as a paronomasia in the context of linguistics, is a form of word play that exploits multiple meanings of a term, or of similar-sounding words, for an intended humorous or rhetorical effect. These ambiguities can arise from the intentional use of homophonic, homographic, metonymic, or figurative language. A pun differs from a malapropism in that a malapropism is an incorrect variation on a correct expression, while a pun involves expressions with multiple (correct or fairly reasonable) interpretations. Puns may be regarded as in-jokes or idiomatic constructions, especially as their usage and meaning are usually specific to a particular language or its culture.

Puns have a long history in writing. For example, the Roman playwright Plautus was famous for his puns and word games.