I use the term Philosophy of Communication to refer to the use of logical and scientific methods to explain the process of communication.

Communication Theory refers, broadly, to the study of the principles by which communication occurs.  I use it to refer to discursive and rhetorical models of communication. 

HERMENEUTICS

Hermeneutics: the term 'hermeneutics' (from the Greek word Ερμηνεύς, 'interpreter') is thought to be derived from the name of the Greek god Hermes who functioned in classical mythology to relay to humans messages sent by the gods.  (Hermes was often depicted as playing tricks on those he was supposed to give messages to, often altering the messages and influencing the interpretation thereof.)  From at least the Middle Ages, the term 'Hermeneutics' was closely tied to the attempt to formulate principles designed to ensure the correct interpretation of the Bible and related texts in the Christian tradition.  However, more recently, it has come to be used in a broader sense to denote the study of the theories and methods involved in the interpretation of texts more generally.  Modern hermeneutics, which takes its lead from its principal exponent in the nineteenth century, Friedrich von Schleiermacher, has come to denote a particular method of interpretation the goal of which is to use the language of the text in question (either oral or written) to 'get inside,' as it were, the author's mind and thereby identify his intention, that is, the specific meaning which s/he has imparted to the words in question.  Recently, the concept of 'text' has been extended beyond merely oral or written texts to include any number of objects (e.g. film, art, society, etc.) that are accordingly treated as texts and, thus, subjected to interpretation.  Hermeneutics has also increasingly come to be seen by many (e.g. Richard Harvey Brown, Richard Rorty) as something of an alternative (so-called interpretivism) to the positivism which informs the currently dominant approaches to epistemology in philosophy and the natural and social sciences. 

Hermeneutical Phenomenology (or Phenomenological Hermeneutics) studies, from a phenomenological perspective, the interpretive structures by which sense is made of experience, that is, the literary and rhetorical strategies through which we seek to understand and engage with things around us in our human world, including ourselves and others.  Key phenomenological hermeneuticists include Martin Heidegger and Hans-Georg Gadamer in the twentieth century.  

Humanist Hermeneutics: hermeneuticists of this 'school' such as Wilhelm Dilthey, Emilio Betti and E. D. Hirsch see themselves as carrying on the tradition of Romantic Hermeneutics epitomised by  Schleiermacher. 

Rhetorical Hermeneutics is about a way of reading texts as a form of rhetoric.

Romantic Hermeneutics: the founder of modern hermeneutics is Friedrich Schleiermacher, a product of the Romantic movement in Germany during the nineteenth century. 

The Hermeneutical Circle: this is the view that if we are to understand the meaning of the whole, we must grasp the meaning of its constituent parts and, by the same token, if we are to understand the meaning of the verbal parts of a linguistic whole, we must also have some prior sense of the meaning of the whole. This circular interpretive process applies to the relationship between individual words and the sentence of which it is part as well the relationship between particular sentences and the work as a whole.

LINGUISTICS

Linguistics is often defined as the field of study devoted to the scientific study of natural language.  It can be either Applied or Theoretical in nature.  Mainstream Linguistics is predicated on at least three core assumptions: that there is a transcendental form, structure or systemic core common to all language (what Saussure calls 'langue' and Chomsky 'competence') which may be scientifically studied; that linguists should seek to neutrally describe, rather than prescribe, the properties of languages; and that spoken language is prior to and more fundamental than written forms of language.

Douglas Robinson labels Oppositional or Counter-Hegemonic Linguistics the views of those linguists who reject the assumption that there is a transcendental form, structure or systemic core common to all language and who contend, rather, that what people actually say or write (discourse) ought to be the focus of study; that the scientific study of language may accordingly be an illusion; and that spoken forms of language may in fact not be prior to written forms.  Some of the major schools of thought studied under this rubric include: Deconstruction, Dialogism, Marxism, Phenomenology, Pragmatism, Psychoanalysis, Romantic Linguistics, and Speech-Act Theory.

Applied Linguistics puts linguistic theories into practice in areas such as foreign language teaching, forensics, lexicography, speech therapy, translation, and speech pathology. 

Forensic Linguistics

Theoretical (or General) Linguistics encompasses a number of sub-fields, branches or topics:

A) Grammar: the study of the structure or form of language, that is, the rules that govern the composition of words, phrases and sentences in any language.  Grammar encompasses

Morphology: the study of the "properties of words and word-building rules" (Akmajian, et al, 6);

The Lexicon of a given language is its vocabulary.

Phonetics: the study of the "physiology involved in the production of speech sounds" (6) and of the "transcription systems used to represent" (6) these sounds;

Phonology: the study of the "organisational principles that determine the patterns that speech sounds are subject to" (6);

Syntax: the study of the "structure of sentences and phrases" (6);

B) Semantics: the study of the production and reception of the meaning of words, phrases and sentences. 

C) Pragmatics the study of the process of communication in the course of which language is put to use, that is, the practical use of language made by individuals and groups in specifiable circumstances.  There are several goals: to explore how the production and reception of the meaning of a proposition is shaped by various aspects of the context in which language-use occurs, not least the social status of those involved; the establishment of the speaker's intention; the study of implicatures (i.e. the difference between manifest and latent levels of meaning); the study of impediments to clear communication such as ambiguity; etc.

D) Comparative (or Synchronic or Descriptive) Linguistics: the study of language variation, that is, the linguistic differences that distinguish individuals and communities from each other.  Comparative Linguistics seeks to determine the relatedness of given languages by grouping them into language families.

E) Historical (or Diachronic) Linguistics: the study of language change, that is, "how languages change over time" (6).  Historical Linguistics has four main concerns: to describe and account for observed changes in particular languages, to describe the history of speech communities, to reconstruct the pre-history of languages, and to develop general theories about how and why language changes. 

Philology (from the Greek philología, love of words) refers to the "study of a culture through its literature" (Sampson 243, n1), a field of study which reached its apogee in Continental Europe especially (and Germany in particular) during the nineteenth century.  Classical philology, for example, "concerned itself with the Latin and Greek languages only as means to a better understanding of Roman and Greek civilisation" (Sampson 243, n1).  However, starting with the Romantic period, an increased emphasis on studying languages "as ends in themselves rather than as literary vehicles" (Sampson 243, n1) gave rise bit by bit to what in Germany came to be called Sprachwissenschaft or Linguistik.  In "modern English usage linguistics normally means linguistics in the twentieth century style -- therefore primarily synchronic linguistics -- while philology, if used at all, refers . . . to historical linguistics as practised in the nineteenth century" (Sampson 243, n1).

Some Definitions:

Overshadowed in the twentieth century by its offspring Linguistics, it continues in a more muted fashion, sharing much with the subdiscipline historical linguistics, and focusing particularly on the evolution of languages, especially in terms of their groupings (‘families’) and their elements (Concise Oxford Companion to the English Language). 

It refers to the study of both language and literature.  In addition to phonetics, grammar and the structure of language, philology also includes literary criticism, etymology, and the study of art, archaeology, religion and any system related to ancient or classical languages (World Encyclopedia). 

It refers to the study of literature and of disciplines relevant to literature or to language as used in literature; the study of human speech especially as the vehicle of literature and as a field of study that sheds light on cultural history (Merriam-Webster Online Dictionary). 

The study of human speech especially as the vehicle of literature and as a field of study that sheds light on cultural history (L. H. Gray Foundations of Language).

The study of the issues outlined above is divided into several approaches:

Formalist approaches emphasise the autonomy of language and accordingly seek explanations of linguistic properties from within the linguistic system itself. 

Generative Linguistics (associated in particular with the work of linguists like Noam Chomsky) is the approach that is currently the dominant paradigm in mainstream Linguistics.  Although it originated as an attempt to explain how human beings acquire language and to grasp the biological constraints shaping this acquisition, it has evolved into a tendency to explain linguistic patterns by means of appeals to structural properties internal to and specific to language.

Structuralist Linguistics (associated with Ferdinand de Saussure) is a forerunner of Generative Grammar that stresses that both grammar and semantics are explicable with reference solely to the properties of language itself. 

Functionalist approaches stress the functional relationship between linguistic and extra-linguistic phenomena and accordingly seek explanations of linguistic properties outside the linguistic system itself.

Biolinguistics

Evolutionary Linguistics is the scientific study of the neurobiological origins and development of language.  It contends that language has evolved in tandem with the development of mental faculties as these have evolved and speciated over time.  The main challenge in this research is the lack of empirical data for the simple reason that spoken language leaves no traces which led to the abandonment of the field for more than a century.  Since the late 1980s, however, the field has been revived in the wake of progress made in the related fields of biology, psycholinguistics, neurolinguistics, evolutionary anthropology and cognitive science.

Psycholinguistics (or Psychology of Language) is the study of the psychological and neurobiological factors that enable humans to acquire, produce, and understand language.  It explores the cognitive processes that make it possible both to generate and comprehend meaningful propositions.  Neurolinguistics is devoted specifically to the study of the neural mechanisms in the human brain that are responsible for these processes.

Cognitive Linguistics is the view (associated with linguists like George Lakoff) that language is best explained by reference to an understanding of the processes of human cognition in general, that is, an effect or function of those basic underlying mental faculties that are common to all humans and studied by cognitive science. 

Sociocultural approaches are "concerned with the intersection of language, culture, and society" (Bucholtz and Hall 5).

Anthropological Linguistics is the branch of Linguistics that studies language through the prism of anthropological accounts of human nature.  Linguistic Anthropology is the branch of Anthropology that studies humans via linguistic accounts of the languages that they use.  Where the former brings anthropological methods to bear on the study of language, the latter brings linguistic methods to bear on anthropological problems.  In both cases, however, a link is drawn between between language, on the one hand, and human biology and culture, on the other.

Sociolinguistics (or the Sociology of Language) is the study of relationship between linguistic variation and change, on the one hand, and differences in social structure, on the other.  It explores the effect of any and all aspects of society on the way language is used by focusing on how 'lects' differ between speech communities (more or less discrete groups of people who use language in a unique and mutually accepted way among themselves) separated by certain social variables (e.g. ethnicity, religion, status, gender, level of education, etc.) and how creation and adherence to these rules is used to categorize individuals in social class or socio-economic classes. 

Corpus (Empirical) Linguistics is the study of language as expressed in samples (corpora) or 'real world' texts.  This method represents a digestive approach to deriving a set of abstract rules by which a natural language is governed or else relates to another language.  Originally done by hand, corpora are now largely derived by an automated processes.

Critical Linguistics is an "enquiry into the relations between signs, meanings and the social and historical conditions which govern the semiotic structure of discourse, using a particular kind of linguistic analysis" (Roger Fowler, Language in the News).

Discourse Analysis is a general term for a number of approaches to analyzing written, spoken or signed forms of language use (speech, written texts, sign-language, etc.). 

Critical Discourse Studies scrutinises the relations between language, social structure and individual agency.  It interrogates institutionalized ways of thinking, socially-derived boundaries defining what can be said about a specific topic and, thus, what can be taken to be true.  It thus studies language as a form of social practice and focuses on the ways in which social and political domination is reproduced (or subverted) through the uses to which language is put (discourses).

Stylistics is the study of varieties of language whose properties position that language in context.  For example, the language of advertising, politics, religion, individual authors, etc., or the language of a period in time, all arguably derive from and thus are explicable with reference to a particular socio-historical situation.

PHILOSOPHY OF LANGUAGE AND LOGIC

Philosophy of Language is largely devoted to understanding the logic by means of which any sign or sequence of signs may be said to have meaning and why a given sign or sequence of signs has the distinctive meaning which it does.  It is also devoted to explaining what enables humans both to produce and to understand meaning.   

Formal Logic (from the Classical Greek λόγος [logos], originally meaning the word or what is spoken and later thought or reason), is the branch of philosophy devoted to the study of arguments, to be precise, the study of patterns found in reasoning and criteria for the evaluation of arguments.  More precisely, logic studies the laws of valid inference.  The task of the logician is to advance an account of valid and fallacious inference to allow one to distinguish logical from flawed arguments.  In short, logicians take arguments apart and study their structure in more detail than a cursory glance would otherwise allow.

Philosophical Logic is the application of formal logical techniques to philosophical problems.  In the UK, according to Anthony Grayling, philosophical logic is the attempt to solve general philosophical problems that arise when we use or think about formal logic: problems about existence, necessity, analyticity, a prioricity, propositions, identity, predication, truth. 

Philosophy of Logic is concerned with the nature and justification of systems of logic, dealing with questions such as whether there exists only a single logic or whether there are many logics.

RHETORIC AND COMPOSITION STUDIES

Rhetoric (from Greek word rhêtôr, orator, teacher, in turn derived from the Greek eiro, I say) refers, broadly speaking, to the art, practice, and study of human communication.  Rhetoric is devoted at least in part to the study of the art or technique of effective speaking and writing within specific situations (e.g. in a court or in parliament) with the goal of persuading a particular audience to adopt a point of view or perform a particular action.  It is concerned, more broadly, with studying the nature of human discourse, how meaning is produced and to what end.  A rhetor is someone who presents a discourse, either written or oral, while a rhetorician is someone who studies the rhetoric of a given discourse, written or oral.

Epistemic Rhetoric: the relationship between rhetoric and knowledge is one of its oldest and most interesting problems confronting rhetoricians.  The stereotype that equates the term 'rhetoric' with the empty or even deceitful use of words is a long-standing one traceable back to Peter Ramus in the Renaissance and, before him, to at least Plato in the course of his conflict with the Sophists and his attempt to differentiate the emerging discipline of 'philosophy' per se from that of Sophism.  It is an attempt to distance the aims of rhetoric from the acquisition of true knowledge.  Many contemporary rhetoricians, however, envisage an intimate relationship between rhetoric and the production of knowledge, positing an inherently literary and social dimension to the latter.  Emphasizing this close relationship between discourse and knowledge, contemporary rhetoricians have tended to see language and discourse as integral to, rather than in conflict with, knowledge-making.  All in all, while

classical rhetoric sought to train speakers to be effective orators in public forums and institutions like the courtroom and political assemblies, contemporary rhetoric seeks to investigate human discourse writ large and, to this end, train their attention on the discourses produced within a wide variety of disciplines, including politics, the law, the natural and social sciences, the fine arts, religious study, journalism, history, cartography, architecture, public relations, lobbying, marketing, professional and technical writing, and advertising, among others.  In short, rhetoric is partly a method for training effective communicators (rhetors) and partly a method for understanding how humans use language ('discourse') to alter or shape our understanding of reality.  I use the term 'rhetoric' here to refer to approaches that emphasise the socio-historical context and literary dimension of human discourse in its attempt to persuade us that a particular truth-claim is correct.  Rhetoric focuses, to these ends, on the "texts, discourses, and cultural practices by which public beliefs and identities are constituted, empowered, and enacted," as the Quarterly Journal of Speech puts it, by exploring the "theory and criticism of situated discourse in its various forms and venues, including the oral, the written, and the visual; official and vernacular; direct and mediated; historical and contemporary."

Argumentation is the process by which humans can, do, and should reach conclusions through logical reasoning, that is, claims based on premises.  It includes the arts and sciences of civil debate, dialogue, conversation, and persuasion.  It studies rules of inference, logic, and procedural rules in both artificial and real world settings.  Frans van Eemeren, Rob Grootendorst, and Snoeck Henkemans define argumentation as a

verbal and social activity of reason aimed at increasing (or decreasing) the acceptability of a controversial standpoint for the listener or reader, by putting forward a constellation of propositions intended to justify (or refute) the standpoint before a rational judge.  (Fundamentals of Argumentation Theory: a Handbook of Historical Backgrounds and Contemporary Developments)

Argumentation Theory studies the credibility of arguments by identifying the premises, conclusions, and fallacies found in various types of communication that occur in every day, practical, real-life situations.  Logic, generally speaking, is devoted to the study of inference.  Formal logic seeks to compare the form of a particular argument with one of the forms of proper inference (that is, whereby the conclusion can be derived from the premises using accepted rules of derivation, or by some other formal method.)  Informal Logic, by contrast, studies inference without formalizing it to any (great) extent.  Ralph Johnson and J. Anthony Blair define Informal Logic as a

branch of logic whose task is to develop non-formal standards, criteria, procedures for the analysis, interpretation, evaluation, criticism and construction of argumentation.  ("The Current State of Informal Logic," Informal Logic 9.2–3 (1987): 147–151). 

In general, the label 'argumentation' is used by speech and communication scholars while the label 'informal logic' is used by philosophers. 

Persuasion is a form of influence that achieves its goal by guiding people toward the adoption of an idea, attitude, or action through rational and symbolic (though not only logical) means and relying on 'appeals' to reason or the emotions, rather than force. 

Rhetorical Analysis / Criticism, in turn, studies the use of language in oral and written texts by a given speaker or writer, focusing not only on the logical development of its argument but also the literary dimensions of a given utterance (not least its use of figurative language and its narrative structure).   

Rhetorical Theory is devoted to the study of the principles informing the production of meaning in discourse (the identity of the author, the signifying processes of language, and so on) and the nature of its impact on audiences.

Composition Studies (also referred to as 'Composition and Rhetoric,' 'College Composition,' or simply 'Composition') is the professional field of writing instruction, especially at the college level in the United States.  Composition scholars study not only the theory and practice of postsecondary writing instruction, but also the influence of different writing conventions and genres on writers' composing processes.   

Rhetoricians on Rhetoric:

The "faculty of observing in any given case the available means of persuasion." (Aristotle, Rhetoric)

"Speech designed to persuade."  (Cicero, )

The "art of speaking well."  (Quintilian, )

Rhetoric is the udder of eloquence; tropes and figures are the teats.  (1690 Harvard senior thesis, qtd. in Perry Miller)

The "use of words by human agents to form attitudes or to induce actions in other human agents. . . .  The use of language as symbolic means of inducing cooperation in beings that by nature respond to symbols."  (Kenneth Burke, Rhetoric of Motives 43)

A "mode of altering reality, not by the direct application of energy to objects, but by the creation of discourse which changes reality through the mediation of thought and action."  (Lloyd Bitzer, )

The "discipline which studies all of the ways in which men may influence each other's thinking and behaviour through the strategic use of symbols."  (Douglas Ehninger, )

Rhetoric is an "organized, consistent, coherent way of talking about practical discourse in any of its forms or modes."  (Douglas Ehninger, On Systems of Rhetoric)

The "functional organization of discourse, within its social and cultural context, in all its aspects, exception made for its realization as a strictly formal metalanguage - in formal logic, mathematics, and in the sciences whose metalanguages share the same features.  In other words: rhetoric is all of language, in its realization as discourse."  (Paolo Valesio, Novantiqua: Rhetorics as a Contemporary Theory 7)

[The problem is bringing] rhetoric, the orator, the struggle of discourse within the field of analysis; not to do, as linguists do, a systematic analysis of rhetorical procedures, but to study discourse, even the discourse of truth, as rhetorical procedures, as ways of conquering, of producing events, of producing decisions, of producing battles, of producing victories.  In order to “rhetoricize” philosophy.  (Michel Foucault, )

What happens, then, if we choose to begin with our knowledge that we are essentially creatures made in symbolic exchange, created in the process of sharing intentions, values, meanings, in fact more like each other than different, more valuable in our commonality than in our idiosyncrasies: not, in fact, anything at all when considered separately from our relations? What happens if we think of ourselves as essentially participants in a field or process or mode of being persons together? If man is essentially a rhetorical animal, in the sense that his nature is discovered and lived only in symbolic process, then the whole world shifts: even the usage of words like I, my, mine, self, must be reconsidered, because the borderlines between the self and the other have either disappeared or shifted sharply . . . All we need do is honour what we know about who we are and how we come to be, in language. Once we give up the limiting notions of language and knowledge willed to us by scientism, we can no longer consider adequate any notion of 'language as a means of communication.' . . . It is, in recent models, the medium in which selves grow, the social invention through which we make each other and the structures that are our world, the shared product of our efforts to cope with experience.  (Wayne C. Booth )

Rhetoric, which was the received form of critical analysis all the way from ancient society to the 18th century, examined the way discourses are constructed in order to achieve certain effects. It was not worried about whether its objects of inquiry were speaking or writing, poetry or philosophy, fiction or historiography: its horizon was nothing less than the field of discursive practices in society as a whole, and its particular interest lay in grasping such practices as forms of power and performance. This is not to say that it ignored the truth-value of the discourses in question, since this could often be crucially relevant to the kinds of effect they produced in their readers and listeners. Rhetoric in its major phase was neither a language, nor a “formalism,” preoccupied simply with analyzing linguistic devices. It looked at such devices in terms of concrete performance-they were means of pleading, persuading, inciting and so on-and at people’s responses to discourse in terms of linguistic structures and the material situations in which they functioned. It saw speaking and writing not merely as textual objects, to be aesthetically contemplated or endlessly deconstructed, but as forms of activity inseparable from the wider social relations between writers and readers, orators and audiences, and as largely unintelligible outside the social purposes and conditions in which they were embedded.  (Terry Eagleton, )

The "process of using language to organize experience and communicate it to others.  It is also the study of how people use language to organize and communicate experience.  The word denotes, as I use it, both a distinctive human activity and the 'science' concerned with understanding that activity.  All human beings are 'rhetors' because they naturally conceive as well as share their knowledge of the world by means of discourse.  Certain individuals are also 'rhetoricians' because they study the nature, operations, and purposes of discourse.  I suggest further that rhetoric, as a generic discipline, encompasses all forms of written as well as oral expression and includes the efforts of undeveloped speakers and writers as well as the achievements of literary artists."  (C. H. Knoblauch, "Modern Rhetorical Theory and its Future Directions" 29)

Rhetoric deals with "questions surrounding any study of language: the relation between language and the world, the relation between discourse and knowledge, the heuristic and communicative functions of verbal expression, the roles of situation and audience in shaping utterance, the social and ethical aspects of discourse. . . ."  (C. H. Knoblauch, )

The "political effectivity of trope and argument in culture.  Such a working definition includes the two traditional meanings of rhetoric: figurative language and persuasive action."  (Stephen Mailloux, Rhetorical Power xii)

The "primordial function of rhetoric is to 'make-known' meaning both to oneself and to others.  Meaning is derived by a human being in and through the interpretive understanding of reality.  Rhetoric is the process of making known that meaning.  Is not rhetoric defined as pragmatic communication, more concerned with the contemporary audiences and specific questions than with universal audiences and general questions?"  (Michael Hyde and Craig Smith, "Hermeneutics and Rhetoric")

The "study of how people use language and other symbols to realize human goals and carry out human activities. . . .  [It is] ultimately a practical study offering people great control over their symbolic activity.  (Charles Bazerman, Shaping Written Knowledge 6)

"Scholars have traditionally defined rhetoric either as the study of schemes and tropes (verbal artifice) or as the study of persuasion."  (George L. Dillon, "Rhetoric")

Rhetoric is the "study of how we organize and employ language effectively, and thus it becomes the study of how we organize our thinking on a wide range of subjects."  (James Herrick, The History and Theory of Rhetoric)

Rhetoric is the art of describing reality through language. Under this definition, the study of rhetoric becomes an effort to understand how humans, in various capacities and in a variety of situations, describe reality through language. To act rhetorically is to use language in asserting or seeming to assert claims about reality. At the heart of this definition is the assumption that what renders discourse potentially persuasive is that a rhetor (e.g. a speaker or writer) implicitly or explicitly sets forth claims that either differ from or cohere with views of reality held by audiences (e.g. a specific scholarly community, a reader of fiction, or an assembly of persons attending a political rally).  (Cherwitz and Hikins, "Communication and Knowledge: An Investigation in Rhetorical Epistemology" 62)

Rhetoric has a number of overlapping meanings: the practice of oratory; the study of the strategies of effective oratory; the use of language, written or spoken, to inform or persuade; the study of the persuasive effects of language; the study of the relation between language and knowledge; the classification and use of tropes and figures; and, of course, the use of empty promises and half-truths as a form of propaganda.  Nor does this list exhaust the definitions that might be given. Rhetoric is a complex discipline with a long history: it is less helpful to try to define it once and for all than to look at the many definitions it has accumulated over the years and to attempt to understand how each arose and how each still inhabits and shapes the field.  (Patricia Bizzell and Bruce Herzberg, "General Introduction." The Rhetorical Tradition: Readings from Classical Times to the Present 1)

SEMIOTICS

Semiotics (from the Greek σημειωτικός, semeiotikos, an interpreter of signs) (or Semiology) is, broadly speaking, the study of the production, communication and interpretation of meaning.  More specifically, it is the study of communication and sign systems, in short, of the ways people understand phenomena and organize them mentally, and of the ways in which they transmit that understanding and share it with others.  Although natural and artificial languages are therefore central to semiotics, its field covers all non-verbal signalling and extends to domains whose communicative dimension is perceived only unconsciously or subliminally.  Knowledge, meaning, intention and action are thus fundamental concepts in the semiotic investigation of phenomena.  (University of Toronto Semiotics and Communication Theory programme).  The focus is on the nature of signs, both individually and grouped in sign systems, by exploring how the meaning of a given sign is a function of its relation to other signs within the sign system in question.  Semiotics studies how meaning is accordingly produced, conveyed and interpreted.  Semiotics differs from Linguistics in that it expands the definition of the sign, sign systems and sign relations beyond mere spoken or written words.  Semiosis is a term coined by Charles Sanders Peirce to denote the process by which signs produce meaning.  Peirce defined semiosis as any "action, or influence, which is, or involves, a cooperation of three subjects, such as a sign, its object, and its interpretant, this tri-relative influence not being in any way resolvable into actions between pairs." (Pragmatism [1907], ).

Semioticians on Semiotics:

The doctrine that our knowledge of the things in the world is mediated by signs, that we build up structures of signs through experience and these structures define what we take as reality.  (Donald Cunningham, )

Semiotics is "coextensive with the whole range of cultural phenomena" (Umberto Eco, )

REASONING

Reasoning is, broadly speaking, the cognitive process of looking for reasons to justify beliefs, conclusions, actions or feelings.  It also refers, more specifically, to the act or process of using one's reason to derive one statement or assertion (the conclusion) from a prior group of statements or assertions (the premises) by means of a given method. 

An argument is an attempt to demonstrate the validity of an assertion called a conclusion based on the truth of a set of assertions called premises.  To put this another way, it is a set of premises (a justification) offered in support of a conclusion (a truth-claim or belief).  It typically comprises a set of assumptions (the premises), a method of reasoning, and a conclusion.  Etymologically-speaking, as Peter Caws has argued in an email to the Philos-L list, the word 'argument' derives (on the mythological side) from Argus, the many-eyed and (on the philological side) from the Latin verb 'arguo,' which means 'to put in a clear light.'  The

main idea is of seeing clearly, getting clear about, throwing light on, and ideally that's what argument would be for.  Formal argument aims for inferences of logical or mathematical clarity; in other cases it's more a matter of give and take in discussion, aiming for an agreement in which the parties come to see whatever it is in the same way, or to understand why they can't do so.  A bad argument would be one that doesn't help in this way, and the worst would presumably be one that produces maximum obscurity rather than clarity.  (Ibid)

A logical assertion is a statement that asserts or claims that a particular premise is valid.  A proposition is the content of an assertion, that is, it is true-or-false and defined by the meaning of a particular piece of language.  The proposition is independent of the medium of communication with the result that different statements may communicate the same proposition.  A logical argument is one in which the validity of the conclusion derives from a logical relationship that exists between the premises themselves, any intermediate assertions that may be present, and the conclusion.  Inference is the act or process of deriving a conclusion from prior premises and takes several forms.  The two most important forms of reasoning are deduction and induction.  A valid argument does not presuppose that one's conclusion is necessarily true, that is, that it corresponds to reality.  Validity is a property of the reasoning in the argument, not a property of the premises in the argument or the argument as a whole.  In fact, the truth or falsity of the premises and the conclusion is irrelevant to the validity of the reasoning in the argument.  An argument may be described as 'truth-preserving' when, if the premises are true, the conclusion is accordingly also true.  Alternatively, an argument may be fallacious, though not necessarily untrue.  Formal fallacies occur when there is a problem with the form, or structure, of the argument.  An informal fallacy is an error in reasoning that occurs due to a problem with the content, rather than mere structure, of the argument. 

Deduction is the process of reasoning in which an assertion (the conclusion) is necessitated by, or derived from, or entailled by previously known facts (the premises).  In other words, if the premises are true, the conclusion must be true.  For example,

Induction is the process of reasoning in which the particular premises of an argument are believed to support a conclusion of a general nature but do not ensure it (e.g. the specific proposition 'this ice is cold' is used to infer that 'all ice is cold').  Even in the best, or strongest, cases of inductive reasoning, the truth of the premises does not guarantee the truth of the conclusion.  Instead, the conclusion of an inductive argument follows with some degree of probability.  In addition, the conclusion of an inductive argument contains more information than is already contained in the premises.  Thus, this method of reasoning is ampliative.  For example,

Abduction (or inference to the best explanation) is a method of reasoning, employed in the sciences especially, in which one chooses which hypothesis would, if true, best explain the relevant evidence.  It is the reasoning process that starts from a set of observed facts and derives their most likely explanations.  What separates abduction from the other forms of reasoning is an attempt to favor one conclusion above others, by attempting to falsify alternative explanations or by demonstrating the likelihood of the favored conclusion, given a set of more or less disputable assumptions.  Though it often involves both inductive and deductive arguments, because the conclusion in an abductive argument does not follow with certainty from its premises it is best thought of as a form of inductive reasoning. 

Argument by analogy, also a form of inductive reasoning, is an inference from one particular to another particular.  It normally takes the following form:

Critical thinking refers to the general process of analyzing or evaluating information, particularly statements or propositions that people have offered as true, by reflecting on the meaning of statements, studying the process of reasoning, examining the offered evidence, and evaluating the judgments proposed in this way.