Editing Michael Halliday (section)

==Linguistic theory and description==
Halliday's grammatical theory and descriptions gained wide recognition after the publication of the first edition of his book ''An Introduction to Functional Grammar'' in 1985. A second edition was published in 1994, and then a third, in which he collaborated with [[C.M.I.M. Matthiessen|Christian Matthiessen]], in 2004. A fourth edition was published in 2014. Halliday's conception of grammar – or "lexicogrammar", a term he coined to argue that lexis and grammar are part of the same phenomenon – is based on a more general theory of language as a social semiotic resource, or "meaning potential" (see [[Systemic functional linguistics]]). Halliday follows [[Louis Hjelmslev|Hjelmslev]] and [[John Rupert Firth|Firth]] in distinguishing theoretical from descriptive categories in linguistics.<ref name="Perspective p. 12">Halliday, "A Personal Perspective". In ''On Grammar'', Vol. 1 in ''The Collected Works'', p. 12.</ref> He argues that "theoretical categories, and their inter-relations, construe an abstract model of language ... they are interlocking and mutually defining.<ref name="Perspective p. 12" /> The theoretical architecture derives from work on the description of natural discourse, and as such 'no very clear line is drawn between '(theoretical) linguistics' and 'applied linguistics'".<ref>Halliday, 2002. "A Personal Perspective". In ''On Grammar''; Vol. 1 in ''The Collected Works'', pp. 7, 14.</ref> So the theory "is continually evolving as it is brought to bear on solving problems of a research or practical nature".<ref name="Perspective p. 12" /> Halliday contrasts theoretical categories with descriptive categories, defined as "categories set up in the description of particular languages".<ref name="Perspective p. 12" /> His descriptive work has focused on English and Mandarin.

Halliday argues against some claims about language associated with the generative tradition. Language, he argues, "cannot be equated with 'the set of all grammatical sentences', whether that set is conceived of as finite or infinite".<ref>Halliday, M.A.K. 1985. Systemic Background. In "Systemic Perspectives on Discourse, Vol. 1: Selected Theoretical Papers" from the ''Ninth International Systemic Workshop'', Benson and Greaves (eds); Vol. 3 in ''The Collected Works'', p. 192.</ref> He rejects the use of formal logic in linguistic theories as "irrelevant to the understanding of language" and the use of such approaches as "disastrous for linguistics".<ref name=Missteps236>Halliday, M.A.K. 1995. "A Recent View of 'Missteps' in Linguistic Theory". In ''Functions of Language'' 2.2. Vol. 3 of ''The Collected Works'', p. 236.</ref> On Chomsky specifically, he writes that "imaginary problems were created by the whole series of dichotomies that Chomsky introduced, or took over unproblematized: not only syntax/semantics but also grammar/lexis, language/thought, competence/performance. Once these dichotomies had been set up, the problem arose of locating and maintaining the boundaries between them."<ref name=Missteps236 />