This book is about the notion of ‘system’ in Systemic Functional Linguistics, or SFL. SFL is a system-based theory of language in context, so ‘system’ is quite central to the theory. There are a number of distinct but related senses of the term “system”, which I identify, explain and differentiate in this introductory chapter. By way of introduction, I give examples of systems of choice in text in context, showing how speakers make choices and then revise them, thereby revealing aspects of the system behind their choices. This key sense of system as a choice or contrast among options in meaning (and wording, and sounding) will run through the whole book, but the related senses of “system” will also be part of the overall picture that I present.

An excellent way of understanding ‘system’ as it has been used in SFL and the phenomena that it was developed to capture is to observe how its manifestations emerge in the course of ontogenesis, from the early phase of young children learning how to mean to the later phase when they have begun to master the mother tongue(s) spoken by members of their immediate meaning group and the wider community that it is part of. In this chapter, I review the systemic functional account of how children learn how to mean from the point of view of the development of the system, beginning with emergence of protolanguage and its separate microfunctional meaning potentials. I use it to illuminate the gradual separation of the two semiotic dimensions of axis and stratification, and introduce the basics of systems forming system networks.

In the previous chapter, I traced ‘system’ in the ontogenesis of language – its emergence as young children learn how to mean as they construct protolanguages in interaction with members of their immediate meaning group, and then make the transition to  the mother tongue (or tongues) spoken by these members. In this chapter, I examine the system as a principle of organization in relation to the other dimensions that make up the organization of language in context, starting with the hierarchy of stratification. While the hierarchies of axiality and stratification are fused in protolanguage, they are separated in the transition to the mother tongue, so the question arises if the axial organization is the same within all strata. I suggest that it is: all strata can be interpreted, represented and described by means system networks although they have not yet been explored to the same extent as the best-described stratum, lexicogrammar, in any language. I illustrate the description of content plane systems within language, semantics and lexicogrammar, and of expression plane systems, phonology and phonetics. The language used for illustration is English, but also Akan and Chinese. Along the way, I touch on central systemic topics: double agnation, systemic fractals, metaphor, the lexicogrammatical continuum, semantic composition. After the sweep through linguistic system networks, I turn to system networks “outside” languages, starting with contextual system networks.

In the previous chapter, I have shown how language can be conceptualized as a resource and represented by means of systems forming system networks. These system networks are ‘dispersed’ throughout the stratal systems that make up language and also the extra-linguistic higher-order system of context. Systemic terms are related across strata by inter-stratal realization so that all of language in fact can be thought of as a gigantic system network. In this chapter, I will discuss some of the consequences of modelling language systemically – of foregrounding the paradigmatic mode of axial order. I show how the system can serve as a cartographic and navigational tool in both descriptions of the linguistic system and the analysis of texts. First I explain the notion of systemic cartography, and then I show how systemic descriptions are used in text analysis, and how systemic text analysis can be presented as systemic scores with chords. In the course of this account, I introduce systemic frequencies in text and relate them to probabilities in the system, noting how this conception of language as a probabilistic system enables us to interpret evolution as gradual change in systemic probabilities and register variation as variation in probabilities. I end the chapter with a summary of the system as a navigational tool.

In the previous chapter, I was concerned with the deployment of systems and system networks as navigational tools in the study of language in general terms, including different regions along the cline of instantiation. Here I will continue on this theme, but move to interfaces between linguistics and applications that are sometimes seen as on the borders between linguistics and other disciplines. Systemic Functional Linguistics has been developed as a resource capable of supporting a wide range of applications; Halliday characterized this kind of linguistics as appliable linguistics. In this chapter, I am concerned with the notion of system in SFL in different domains of applications – centrally applications where system networks are used as representation of choice. As a kind of appliable linguistics, SFL has been deployed in a wide range of contexts, but I will only focus on examples of those where the system plays a central role. Thus in this chapter, I will only illustrate the appliability of ‘system’; and I will not focus on other aspects of SFL that have turned out to be of crucial importance in various areas of application.

In the previous chapters, I have presented the systemic functional conception of language, and also of other semiotic systems, and illustrated how system networks have been used to represent ontogenesis and learning how to mean (Chapter 2), to describe all of the strata of language in context (Chapter 3), to map out the resources of language (Chapter 4) and to engage in different fields of application (Chapter 5). Along the way, I have identified various challenges such as the interpretation of recursive system networks used in the representation of logical resources and of marking conventions while I have highlighted possibilities opened up by the systemic angle of approach and the representation of axial order in language by means of system networks. In this chapter,  I will focus on both challenges and possibilities, starting with a review of the benefits of what we might call the ‘systemic turn’ in linguistics contributed by systemic functional linguistics as a way of understanding language and other semiotic systems as resources. I then compare and contrast possible representations of systemic organization other than system networks — taxonomies, mind maps, flow charts — and explain why system networks have advantages, and illustrate how we can move between systemic representations. Next I identify a challenge to system networks, viz. patterns of agnation that are hard to capture by means of such networks, and I review the complementarity of systemic typologies and topologies, and experiments with fuzzy set theory. I also suggest how indeterminacy can be handled by means of system network, pointing to certain difficulties. Finally, I introduce possible enhancements to system networks, including multilingual system networks, going on to illustrate how they can also be used in language comparison and typology. I end the chapter with a summary of challenges and opportunities.

Each chapter of this book has its own summary, and, to a certain extent, the chapters can be read independently of one another (hence the many cross references). Instead of summarizing the book here, touching on the presentation in the previous chapters on the distinct but related senses of ‘system’ identified in Chapter 1, here I take a step back and try to contextualize, or even recontextualize, ‘system’ in the light of the previous chapters but with additional perspectives that are possible to adopt only at this point.  I begin by viewing axiality, i.e. axial order (paradigmatic vs. syntagmatic) trinocularly. I then suggest an analogy between the distinction between paradigmatic and syntagmatic order and David Bohm’s distinction between implicate and explicate order. Finally, I return to the view of ‘system’ in an ordered typology of systems operating in different phenomenal realms, again noting the connection between SFL and different manifestations of systems thinking – as one possible preamble to future research.

Systemic Functional Linguistics is unique among linguistic theories in treating the concept of system as the central organising principle of language (and also of other semiotic systems, including context), most theories being focussed on syntagmatic structure. This book introduces the notion of system as the foundation of the systemic functional architecture of language, relating the general notion of system in systems thinking (holistic approaches) to the principle that language is organised as a system of systems (the polysystemic principle) and, by another step, to the technical sense of system in SFL as the basic category of paradigmatic patterning – i.e. the organisation of language as a resource for making meaning. The concept of system is then used to explore the emergence of complexity in language (within different semogenetic timeframes), to show how it is manifested in the organisation of all subsystems of language (the fractal principle), to illustrate the system at work in the development of language descriptions and in the process of text analysis, to reveal the power of the system in different areas of application, e.g. in computational modelling, in educational analysis and curriculum development, in multilingual and multimodal studies. Finally, challenges are identified e.g. in the relationship between the paradigmatic axis and the syntagmatic one, in the representation of logical iteration and interpersonal continua; and current and new opportunities are suggested.