Yaegan Doran's ISFC 50 Plenary Abstract

Modelling Context: Field, tenor and mode from multiple perspectives

Abstract

That language functions in its context of use is one of the fundamental tenets of SFL. This tenet has supported decades of SFL work into different registers and has contributed to a wide range of applied goals. It has also driven progressive theoretical modelling of context in SFL, even if there has not yet been consensus. This talk will reflect upon this modelling, fifty years after Halliday’s 1975 paper ‘Language as social semiotic: Toward a general sociolinguistic theory’. It will view context trinocularly – not in the typical sense of above, around and below, but in terms of three major dimensions of SFL theory: realisation, instantiation and individuation. Viewing context in this way will allow us to model field, tenor and mode along three distinct contours: in terms of realisation, field, tenor and mode can be viewed as resources for making meaning; for instantiation, they can be viewed as sets of principles for the co-selection and arrangement of choices in language; and for individuation, they can be viewed as domains of variation, contestation and collaboration. This talk will argue that these different perspectives are complementary, providing a view of a wide-range of things our model of context needs to grapple with. But it will also argue that each perspective needs to be modelled in different ways so as to support text analysis and an understanding of social semiosis more broadly. The talk will thus aim to synthesise where we have gotten to in SFL contextual linguistics, and look forward to how we might further expand our worldview.

Blogger Comments:

This abstract describes the paper Rethinking Context: Realisation, Instantiation, And Individuation In Systemic Functional Linguistics (Doran, Martin and Herrington 2024) which is reviewed in meticulous detail at Rethinking Context: Realisation, Instantiation, And Individuation In Systemic Functional Linguistics.

As the review demonstrates, in that paper, the authors misunderstood the dimensions of stratification ("realisation"), instantiation and individuation. The first half of the paper "reconceptualised" the contextual parameters of context, field tenor and mode, as the ideational, interpersonal and textual language that realises each. That is, the authors simply mistook one level of symbolic abstraction for another.

The second half of the paper then "reconceptualised" the original notions of contextual field tenor and mode as 'principles of instantiation' of language, thereby misunderstanding instantiation as an interstratal relation between context and language.

The relevance of individuation was only briefly declared, rather than explored, but it confused individuation as a scale of variation from the reservoir of meanings of a language community to the repertoires of meanings of individuals, whose organising principle is one of elaboration (subtypes of types), with allocation and affiliation, both of whose organising principle is one of extension (association). See Halliday & Matthiessen (1999: 145-6).

ChatGPT Comments:

Context in a Hall of Mirrors: A Critique of Doran’s “Modelling Context”

1. Introduction: A Recurring Confusion

Yaegan Doran’s ISFC50 abstract, Modelling Context: Field, tenor and mode from multiple perspectives, reprises a confusion that has surfaced repeatedly in recent Sydney school publications. It presents as theoretical innovation a series of metaphorical manoeuvres that misrepresent foundational dimensions of Systemic Functional Linguistics (SFL). The abstract aligns with the paper Rethinking Context: Realisation, Instantiation, and Individuation in Systemic Functional Linguistics (Doran, Martin & Herrington, 2024), which is critiqued in detail elsewhere. Here, I offer a briefer but sharper critique of both the content and rhetorical strategies of the abstract, before situating its manoeuvres within a broader pattern of what I call metaphorical opportunism in the Sydney school.

2. Misunderstanding Realisation: The Collapse of Context into Semantics

The abstract proposes to model context "trinocularly," along the dimensions of realisation, instantiation, and individuation. But what follows is not an application of these dimensions to context — rather, it is a substitution of the semantic for the contextual.

The abstract claims that, "in terms of realisation, field, tenor and mode can be viewed as resources for making meaning." But this is a misunderstanding. In Halliday’s theory, field, tenor and mode are parameters of the context of situation, realised by ideational, interpersonal and textual meaning respectively. They are not themselves meaning resources. To treat them as such is to confuse the stratum of context with that of semantics — to collapse one level of symbolic abstraction into another.

This manoeuvre reframes the contextual parameters as though they were metafunctional resources, implying that field is ideational meaning, tenor is interpersonal meaning, and mode is textual meaning. But in SFL, metafunctions are realised by lexicogrammatical systems; contextual parameters are realised through metafunctional semantics. To conflate them is to erase the stratal boundary between context and language, undermining the architecture of the model.

3. Misunderstanding Instantiation: From Meaning Potential to Situational Principles

In a further move, the abstract proposes that, "for instantiation, [field, tenor and mode] can be viewed as sets of principles for the co-selection and arrangement of choices in language." Again, this misrepresents a fundamental category. Instantiation is the relation between a system’s potential and its instances. It does not refer to how context constrains linguistic choice — that is the function of context, not the definition of instantiation.

What Doran offers is not a model of instantiation but a rebranding of context as a kind of ‘control system’ for language — a view which collapses instantiation into an interstratal process, rather than recognising it as a dimension orthogonal to stratification. The abstract thus substitutes a theory of control for a theory of instantiation, and reinterprets the context of situation as a set of principles operating within language.

4. Misunderstanding Individuation: Mixing Allocation, Affiliation and Elaboration

The abstract gives only brief mention to individuation, suggesting that field, tenor and mode can be viewed as “domains of variation, contestation and collaboration.” But this description conflates several distinct processes.

Halliday and Matthiessen (1999: 145–6) distinguish between:

• Elaboration: the principle governing individuation, which organises subtypes of meaning potential — from the reservoir of the culture to the repertoires of individuals;

• Extension: the principle governing affiliation and allocation, which organises associations among speakers and speech roles.

Doran’s account blends these without clarity. “Variation” suggests elaboration; “contestation and collaboration” suggest extension. The result is a vague gesture at individuation that collapses it into neighbouring domains, offering thematic resonance instead of analytic traction.

5. Rhetorical Strategies: Gesturing Towards Synthesis, Avoiding Commitment

The overall strategy of the abstract is not to argue for a new model of context, but to reframe known categories through metaphor. It avoids committing to theoretical definitions, preferring suggestive rewordings and image-rich paraphrases. “Trinocular perspective,” for instance, is repurposed from Halliday’s original metaphor (above, around, below) and applied to three dimensions that are not perspectives on a single object but ontologically distinct planes of organisation.

This is not theoretical synthesis. It is semiotic window-dressing — a kind of metaphorical kaleidoscope in which familiar terms are turned to new angles to suggest complexity without delivering precision. The appearance of insight is sustained by the rhetorical strategy of non-committal parallelism: “field, tenor and mode can be viewed as…”, repeated with varying completions. This lends the text an air of systematicity while avoiding the responsibility of system-building.

6. Metaphorical Opportunism: A Broader Pattern in the Sydney School

The errors in Doran’s abstract are not isolated. They reflect a deeper and more pervasive pattern within the Sydney school’s approach to theoretical development — a pattern of metaphorical opportunism, in which metaphors are deployed not to illuminate distinctions but to paper over them.

In Halliday’s theory, metaphors are powerful tools for explicating system — as in grammatical metaphor — but the discipline lies in mapping metaphors precisely onto functional categories. In the Sydney school, by contrast, metaphor has drifted into a mode of exposition in which loosely associated images are treated as theoretical mechanisms. Dimensions like realisation, instantiation, and individuation are no longer grounded in the architecture of the theory but redefined by what they can be made to resemble in the moment.

Doran’s abstract is a perfect example. The metaphor of a “trinocular” perspective — originally a heuristic for observing language from above (semantics), below (phonology), and around (lexicogrammar) — is reappropriated to frame realisation, instantiation and individuation as “views” on context. But these are not alternative perspectives on the same object. They are distinct dimensions of the theory, and each organises different kinds of relations. Realisation organises symbolic abstraction; instantiation organises the potential–instance relation; individuation organises the relation between social and personal meaning potential. Treating them as interchangeable lenses is not a theoretical insight — it’s a category mistake.

The deeper problem is that this opportunistic use of metaphor is self-insulating. Because metaphors are not evaluated for theoretical consistency but for rhetorical effect, they can always be reinterpreted or replaced when challenged. What appears to be a theoretical model is often a shifting palimpsest of metaphors, each of which suggests structure without committing to any. The result is an illusion of synthesis — a constellation of phrases that sound as though they add up to a system, but which evade analysis when probed.

This strategy is particularly attractive when addressing the more abstract dimensions of SFL — notably, instantiation and individuation — where the temptation to rely on imagery increases as conceptual clarity declines. Rather than clarifying these dimensions, Doran's abstract offers them up as thematic motifs to be rearranged in metaphorical combinations. This is not modelling; it is bricolage.

This approach has rhetorical power. It creates the impression of theoretical depth, the promise of synthesis, and the aesthetic of innovation. But it comes at a cost. The architecture of the theory is eroded, distinctions collapse, and terms lose their analytic value. Under the banner of expanding the worldview, what is actually expanded is the range of plausible-sounding metaphors. And with each new iteration, it becomes harder to retrieve the conceptual rigour that once underpinned the model.

7. Conclusion: Context Lost in the Mirror Maze

Doran’s abstract reads like a theoretical hall of mirrors: each familiar term reflects another, but the reflections are distorted. Context becomes semantics; semantics becomes system; system becomes metaphor. The architecture that once scaffolded systemic functional theory is replaced by a fluid ensemble of rhetorical effects.

If there is to be progress in modelling context within SFL, it will not come from treating its dimensions as interchangeable perspectives. It will come from clarifying the architecture of the theory, preserving its distinctions, and resisting the lure of metaphor when what is needed is logic. What the field requires now is not a new way of seeing context, but a better way of thinking it.

A Close Examination Of Yaegan Doran's 2023 ASFLA Plenary Abstract

Negotiating social relations: Viewing tenor from multiple perspectives

Whenever we talk or write, we negotiate our social relations. This may involve small seemingly inconsequential chats with friends, families and colleagues that help us stay in contact and possibly get us closer to them; or they may be large, momentous events that bring us together or tear us apart. In all cases, we negotiate these social relations through the discourse we use – through language and a range of related semiotic resources. In SFL, this has typically been explored through tenor, a variable of context (Halliday 1978; or register, Martin 1992, depending on the model being used). Tenor has variously been described in terms of the 'roles played by those taking part’ in a situation, ‘the values that the interactants imbue’ the activity with (Halliday & Matthiessen 2014: 33) and the relationships between addressees or interactants (Gregory 1967; Hasan 2020). Or, more broadly, the ‘general dimensions of social relations’ (Poynton 1990:70) and their negotiation (Martin 1992: 523). However, to this point, there has been little by way of comprehensive models of tenor that have been able to link the various dimensions underpinning our social relations with the set of language resources that realise them, in particular, resources within the interpersonal metafunction (Hasan 2020 and related work such as Butt et al. 2021 being perhaps the most comprehensive proposal thus far).

As a step toward such a model, this talk will focus on how we can consider tenor in SFL in relation to recent expansions of SFL theory that have distinguished realisation, instantiation and individuation (Halliday 1991, Matthiessen 1993, Martin 2010). It will propose that a fruitful avenue for understanding the link between language and social relations is to view tenor from these multiple perspectives. 

From the perspective of realisation, tenor can be viewed as a set of resources for enacting social relations (drawing on a model developed in Doran, Martin and Zappavigna forthcoming). 

From the perspective of instantiation, it can be viewed as sets of guiding principles that underly how we co-select and arrange different language features (such as the principles of status and contact, described by, e.g. Poynton 1990, Martin 1992, Hasan 2020 and Butt et al. 2021). 

And in terms of individuation, it can be viewed as sets of social roles and relationships – or more broadly, arenas of sociality – that offer possibilities for variation, contestation and collaboration, in terms of the meaning making resources that are taken up or presumed. 

In short, given the major role tenor plays in our understanding of how language and broader semiosis enacts social relations, this talk will propose that it is time to give it the theoretical space it needs.

Blogger Comments:

To be clear, the fundamental misunderstanding in this abstract, as in two of Doran's previous seminars on the subject, is the confusion of interpersonal context with interpersonal semantics. This is a consequence of not understanding the meaning of distinct levels of symbolic abstraction. See further below.

[1] To be clear, even in Martin's model, negotiation is a matter of discourse semantics, whereas social relations are a matter of context. Speakers and writers do not negotiate tenor variables. For example, the essay of a primary school student does not negotiate the status roles  — equal or unequal power — with the teacher for whom the essay was written. In his work, The Lord Of The Rings, the author Tolkien does not negotiate the contact roles — familiar or unfamiliar — of himself with his readers.

What speakers and writers potentially negotiate are their propositions and proposals — statements, questions, offers and commands — their speech functional moves in exchanges, as realised by the grammar of MOOD. But such negotiation is largely restricted to the semantics that realise dialogic MODE. For example, what propositions or proposals does Lewis Carroll negotiate with his readers in The Hunting Of The Snark?

[2] To be clear, the linking of social relations with the interpersonal language that realise them is not a model of tenor. It is a description of interstratal relations: how tenor variables are realised by semantic options. See [4] below.

[3] This misunderstands realisation. Specifically, it confuses context with the language that realises it. That is, the set of resources for enacting social relations as meaning is interpersonal language, not tenor. Tenor is the interpersonal context that language realises.

[4] This confuses instantiation with interstratal realisation. From the perspective of instantiation, tenor is the interpersonal dimension of the culture > subcultures/situation types > situations. The notion of tenor as "guiding principles" for the selection of language features is modelled in SFL Theory by interstratal preselection. Halliday & Matthiessen (1999: 375):

At the same time, this stratal organisation means that it is crucial to specify the realisational relations between strata — inter-stratal realisation. … More specifically, inter-stratal realisation is specified by means of inter-stratal preselection: contextual features are realised by preselection within the semantic system, semantic features are realised by preselection within the lexicogrammatical system, and lexicogrammatical features are realised by preselection within the phonological/graphological system. This type of preselection may take different forms between different strata! boundaries, but the principle is quite general.

[5] To be clear, individuation is the process of creating different types of individuals. Individuated tenor thus refers to the different types of tenor (from potential to instance) at the level of the individual. Moving up the cline of individuation (of tenor) is moving up to ever more inclusive types of individuations (of tenor). This is distinct from the individuation of language, and the use of language to contest and collaborate.

[6] To be clear, this presents Doran's paper as righting a wrong, which, in terms of logical fallacies, might be interpreted as an appeal to emotion.

Hasan On The Bi-directionality Of Realisation

Realisation works somewhat differently in the two directions. In the encoding view, it is an activation of some possible choice at the next lower level: thus in the production of an utterance, context activates meaning, meaning activates wording. By contrast, in the reception of the utterance, realisation is construal of the relevant choice at the higher level: thus in decoding an utterance, the choice in wording construes meaning, the choice in meaning construes context. (Hasan, 2010: 12).

Blogger Comments:

If we turn SFL Theory back on itself, 'realisation' is an intensive identifying process that relates lower and higher levels of symbolic abstraction. Applied to the stratification hierarchy

• wording (Token) realises (Process) meaning (Value);
• meaning (Token) realises (Process) context (Value).

Identifying processes have two directions of coding: encoding and decoding:

• in encoding, the identity encodes the Value by reference to the Token;
• in decoding, the identity decodes the Token by reference to the Value.

Applied to the stratification hierarchy, in encoding

• the identity encodes meaning by reference to wording;
• the identity encodes context by reference to meaning.

Applied to the stratification hierarchy, in decoding

• the identity decodes wording by reference to meaning;
• the identity decodes meaning by reference to context.

However, Hasan interprets encoding as higher level (Value) activates lower level (Token)

• context activates meaning;
• meaning activates wording.

and interprets decoding as lower level (Token) construes higher level (Value)

• wording construes meaning;
• meaning construes context.

The key problem with Hasan's interpretation is that neither 'activate' nor 'construe' serves as an intensive identifying process, and so neither can serve as a 'direction' of the intensive identifying process 'realise'. 

'Activate' can be interpreted as either a material process or a qualitative attributive process ('make active'), and 'construe' here serves as a metaphorical mental process, with the lower level as Senser and the higher level as Phenomenon (which has the effect of assigning consciousness to the lower level in each case).

Importantly, while 'activate' is inconsistent with the principle on which the stratal hierarchy is founded, 'construe' is not, though it is not synonymous with 'realise'. With 'construe', the claim is the lower level 'intellectually constructs' the higher level. That is, meaning is intellectually constructed by wording, and context is intellectually constructed by meaning.

A further problem is the proposed one-to-one association of encoding with production and decoding with reception, since decoding and encoding are involved in both production and reception

• wording is decoded by reference to meaning (meaning identifies wording);
• meaning is encoded by reference to wording (wording identifies meaning).

Both the speaker and the listener are simultaneously decoding wordings by reference to meanings and encoding meanings by reference to wordings in a speech event.

The Realisation Of Meaning In Wording

The Global And Local Dimensions That Define The Architecture Of Language

Halliday & Matthiessen (2014: 20, 31-2)

… We have now introduced the major semiotic dimensions that define the ‘architecture’ of language in context. Some of these dimensions enable us to locate lexicogrammar in relation to the other sub-systems that make up the total system of language; these are known as global dimensions because they determine the overall organisation of language in context: the hierarchy of stratification, the cline of instantiation, and the spectrum of metafunctions. The other dimensions enable us to characterise the internal organisation of lexicogrammar and also of the other sub-systems of language, and of context; these are known as local dimensions because they operate locally within linguistic sub-systems. Let us summarise the semiotic dimensions of language in context under these two headings: see Table 1-7. 

What Does The Theoretical Term 'Realisation' Actually Mean Precisely?

Linguistic theory is 'language turned back on itself'. This just means that linguistic theory is the use of language to model language.

As a consequence, the language of theory can be analysed in terms of the theory of language.

For example, the theoretical relation of 'realisation' can be understood in terms of grammatical theory.

In transitivity theory, 'realise' is an intensive identifying Process — subtype 'symbol'.

It construes an identity between two levels of symbolic abstraction: a lower Token and a higher Value.

In an identity relation, either level can be used to identify the other.

If the lower Token is used to identify the higher Value, the relation is encoding:

the identity encodes the Value by reference to the Token.

If the higher Value is used to identify the lower Token, the relation is decoding:

the identity decodes the Token by reference to the Value.

So when the language of theory says that the stratum of wording (lexicogrammar) realises the stratum of meaning (semantics), the theory of language says that this construes an identity between two levels of symbolic abstraction, a lower Token (wording) and a higher Value (meaning).

If the lower Token (wording) is used to identify the higher Value (meaning), then the identity encodes the meaning by reference to the wording.

If the higher Value (meaning) is used to identify the lower Token (wording), then the identity decodes the wording by reference to the meaning.

(In this regard, Halliday's argument in On the ineffability of grammatical categories was that a theory of meaning can only be encoded by reference to a theory of wording.  That is, a theory of wording cannot be decoded by reference to a theory of meaning.)

Similarly, when the language of theory says that form (e.g. verbal group) realises function (e.g. Process), the theory of language says that this construes an identity between two levels of symbolic abstraction, a lower Token (form) and a higher Value (function).

If the lower Token (form) is used to identify the higher Value (function), then the identity encodes the function by reference to the form.

If the higher Value (function) is used to identify the lower Token (form), then the identity decodes the form by reference to the function.

Finally, when the language of theory says that structure (syntagmatic axis) realises system (paradigmatic axis), the theory of language says that this construes an identity between two levels of symbolic abstraction, a lower Token (structure) and a higher Value (system).

If the lower Token (structure) is used to identify the higher Value (system), then the identity encodes the system by reference to the structure.

If the higher Value (system) is used to identify the lower Token (structure), then the identity decodes the structure by reference to the system.

Congruent vs Metaphorical Grammatical Realisations

Halliday & Matthiessen (1999: 279-80):

Delicacy, Realisation And Instantiation As Modes Of Relational Processes

Halliday & Matthiessen (1999: 145):

Congruent Lexicogrammatical Realisations Of Semantic Elements

Halliday & Matthiessen (1999: 55):

Congruent Lexicogrammatical Realisations Of Semantic Phenomena

Halliday & Matthiessen (1999: 49):

The Distinction Between Generality, Abstraction And Instantiation In SFL

Halliday & Matthiessen (1999: 615):

General terms are not necessarily abstract; a bird is no more abstract than a pigeon.

Halliday & Matthiessen (1999: 144-5):

In other words, the elaboration sets up a relationship either of 

• generality (delicacy), of 
• abstraction (realisation), or of 
• token to type (instantiation);

Blogger Comments:

1. Generality/delicacy is equivalent to hyponymy and can be construed as either an identifying or attributive relation;
2. Abstraction/realisation can only be construed as an identifying relation;
3. Instantiation can only be construed as an attributive relation.

A Critical Examination Of Jim Martin's ISFC 2017 Plenary Abstract

James R Martin

University of Sydney

Martin Centre for Appliable Linguistics, Shanghai Jiao Tong University

​The tyranny of metafunctions: transcending trinocularity in SFL

SFL is well known for its trinocular vision: three language strata (phonology, lexicogrammar, and discourse semantics), three metafunctions (ideational, interpersonal and textual) and three hierarchies (realisation, instantiation and individuation). And each trinity is a complementarity, not a partition – always already there; you can’t do meaning from any one perspective without the other two.

In this paper I will take the trinocularity of metafunction as point of departure, and consider its role in both enabling and disabling the evolution of SFL. I’ll begin with context, and issues arising with respect to modelling register and genre. I then turn to disciplinarity, and problems arising from a purely ideational view of knowledge structure. As a third step I’ll look at identity and the need for an [sic] transfunctional view of communion.

In conclusion I’ll comment on the way in which the centrality of metafunction to our conception of language has shaped the evolving architecture of the theory as a whole, as scholars expand the frontiers of social semiotics from the standpoint of SFL’s dialectic of theory and practice (i.e. appliable linguistics).

Blogger Comments:

[1] The reason Martin is attempting to demonise the metafunctions here, through such negative appraisals as 'tyranny' and 'disabling', is that his model of genre is not differentiated metafunctionally.  That is, this talk is, inter alia, an attempt rebrand one of the defects in his model as a strength.

[2] This is misleading.  The three language strata in SFL are phonology, lexicogrammar and semantics.  The stratum of discourse semantics is Martin's invention only, and it is theorised on multiple misunderstandings of the categories and scales of SFL theory, as demonstrated in great detail here.

[3] This misunderstands realisation.  Realisation is not a hierarchy.  Realisation is the relation between two levels of symbolic abstraction, and it obtains along several different dimensions of SFL theory; e.g. 

• between axes: syntagmatic structure realises paradigmatic system;
• between ranks: group/phrase rank syntagms (forms) realise clause rank function structures;
• between strata: lexicogrammar realises semantics; and
• within semantics: metaphorical meanings realise congruent meanings — see Halliday & Matthiessen (1999: 288) or here.

Note that Martin (1992) understands neither realisation nor instantiation, as demonstrated here (realisation) and here (instantiation).

[4] The reason Martin uses the word 'partition' here, instead of the more appropriate word 'module', is that his own model is theorised on his misunderstanding of SFL as a modular theory.  Martin (1992: 390):

Each of the presentations of linguistic text forming resources considered above adopted a modular perspective. As far as English Text is concerned this has two main dimensions: stratification and, within strata, metafunction.

Martin (1992: 391):

Within discourse semantics, the ways in which systems co-operate in the process of making text is much less well understood. … A more explicit account of this co-operation is clearly an urgent research goal; English Text has been concerned not so much with addressing this goal as with making it addressable by proposing four relatively independent discourse modules to beg the question [sic] … . The point is that integrating meanings deriving from different metafunctions is not a task that can be left to lexicogrammar alone.

Martin (1992: 488):

In this chapter a brief sketch of some of the ways in which discourse semantics interacts with lexicogrammar and phonology has been presented. The problem addressed is a fundamental concern of modular models of semiosis — namely, once modules are distinguished, how do they interface? What is the nature of the conversation among components?

As Halliday & Webster (2009: 231) point out, SFL is a dimensional theory, not a modular theory:

In SFL language is described, or “modelled”, in terms of several dimensions, or parameters, which taken together define the “architecture” of language. These are 

• (i) the hierarchy of strata (context, semantics, lexicogrammar, phonology, phonetics; related by realisation); 
• (ii) the hierarchy of rank (e.g. clause, phrase/group, word, morpheme; related by composition); 
• (iii) the cline of instantiation (system to instance); 
• (iv) the cline of delicacy (least delicate to most delicate, or grossest to finest); 
• (v) the opposition of axis (paradigmatic and syntagmatic); 
• (vi) the organisation by metafunction (ideational (experiential, logical), interpersonal, textual).

[5] This confuses language with linguistics.  We don't "do" meaning from metafunctional perspectives, but we can analyse it from one or all metafunctional perspectives, using a theory that models meaning in terms of metafunctions.

[6] This is misleading.  The context stratum in SFL construes the culture as a semiotic system.  The stratification of context into genre and register — i.e. context–specific varieties of language — is Martin's invention only, and it is theorised on multiple misunderstandings of the categories and scales of SFL theory, as demonstrated in great detail here (context), here (genre) and here (register).

[7] This is misleading. In SFL, knowledge is modelled as meaning, and meaning is modelled in terms of all three metafunctions. Halliday & Matthiessen (1999: x):

… “understanding” something is transforming it into meaning, and to “know” is to have performed that transformation. There is a significant strand in the study of language […] whereby “knowledge” is modelled semiotically: that is, as system–&–process of meaning, in abstract terms which derive from the modelling of grammar.

The notion of a "purely ideational view of knowledge structure" is thus an example of the logical fallacy known as the attacking a strawman:

A straw man is a common form of argument and is an informal fallacy based on giving the impression of refuting an opponent's argument, while refuting an argument that was not advanced by that opponent. One who engages in this fallacy is said to be "attacking a straw man".

This strawman necessarily has its origins in a misunderstanding of SFL theory by Martin himself.  One possibility would be that he has confused knowledge with field, the ideational dimension of the cultural context (misconstrued by Martin as register).  See here for some of the misunderstandings of field in Martin (1992).

[8] The interest in 'communion' here, as with Martin's previous work on affiliation, reflects Martin's true ideological position.  Bertrand Russell, in his History Of Western Philosophy (pp 21-2), identifies this, and explains why it is consistent with Martin's hostility to science, his interest in heroes, like Nelson Mandela (Martin & Rose 2007), his opposition to liberal humanism (Martin 1992: 587-8), and his treatment of students:

Throughout this long development, from 600 BC to the present day, philosophers have been divided into those who wished to tighten social bonds and those who wished to relax them.  With this difference, others have been associated.  The disciplinarians have advocated some system of dogma, either old or new, and have therefore been compelled to be, in greater or lesser degree, hostile to science, since their dogmas could not be proved empirically.  They have almost invariably taught that happiness is not the good, but that ‘nobility’ or ‘heroism’ is to be preferred.  They have had a sympathy with irrational parts of human nature, since they have felt reason to be inimical to social cohesion.  The libertarians, on the other hand, with the exception of the extreme anarchists, have tended to be scientific, utilitarian, rationalistic, hostile to violent passion, and enemies of all the more profound forms of religion.  This conflict existed in Greece before the rise of what we recognise as philosophy, and is already quite explicit in the earliest Greek thought.  In changing forms, it has persisted down to the present day, and no doubt will persist for many ages to come.

Text: Instantiation Vs Stratification

 Halliday & Matthiessen (2004: 587):

A text is thus a unit of meaning — more accurately, a unit in the flow of meaning that is always taking place at the instance pole of the cline of instantiation.

Instantiation Perspective: Text As Instance Of System Potential

Halliday & Matthiessen (2004: 23):

A text is the product of ongoing selection in a very large network of systems — a system network.

Halliday & Matthiessen (2004: 33):

In the form that we typically receive it, as spoken and written discourse, a text is the product of two processes combined: instantiation and realisation. The defining criterion is instantiation: text as instance. But realisation comes in because what becomes accessible to us is the text as realised in sound or writing. We cannot directly access instances of language at higher strata — as selections in meaning, or even in wording.

Halliday & Matthiessen (2004: 524):

Text is something that happens in the form of talking or writing, listening or reading. When we analyse it, we analyse the product of this process; and the term ‘text’ is usually taken as referring to the product — especially the product in its written form, since this is most clearly perceptible as an object … . The organisation of text is semantic rather than formal, and much looser than that of grammatical units. The organisation of text has typically been represented in some form of structural notation. But it is important to to be able to think of text dynamically, as an ongoing process of meaning.

Stratification Perspective: Text As Semantic Stratum Unit

Halliday & Matthiessen (2004: 588, 588n):

The upper bound of the semantic stratum is the text: this is the most extensive unit of meaning. The upper bound of the lexicogrammatical system is the clause: this is the most extensive unit of wording. … By saying that they are the upper bounds, we are not ruling out complexes — text complexes and clause complexes … . But complexes are not higher–ranking units but rather expansions of units of a given rank.

Halliday & Matthiessen (1999: 122-3):

Texts and sequences are of the same order of abstraction; both are semantic phenomena. A text is a piece of language that is functional in context. It draws on the ideational meaning base but it involves the full metafunctional spectrum; i.e. there are interpersonal and textual contributions as well. Since text draws on the ideational meaning base, sequences are one principle for organising text. 

How Are The Paradigmatic And Syntagmatic Axes Related?

System is more abstract than structure:

Halliday & Matthiessen (2004: 22):

It will be clear that [system] is a more abstract representation than that of structure, since it does not depend on how the categories are expressed.

so syntagmatic organisation realises paradigmatic organisation:

Halliday & Matthiessen (2004: 24):

Structural operations — inserting elements, ordering elements, and so on — are explained as realising systemic choices. … When we speak of structural features as ‘realising’ systemic choices, this is one manifestation of a general relationship that pervades every quarter of language. Realisation derives from the fact that a language is a stratified system.

Halliday & Matthiessen (1999: 13):

… on the one hand, syntagmatic organisation realises paradigmatic organisation; on the other hand, types in a network of paradigmatic organisation correspond to fragments of syntagmatic specification …

Realisation: Encoding & Decoding

In an identifying relation, the identity either encodes the Value (the higher level of abstraction) by reference to the Token (the lower level of abstraction), or it decodes the Token by reference to the Value (Halliday & Matthiessen 2004: 230).

So, in the identifying relation: expression realises content, 

the identity either encodes content by reference to expression,

or it decodes expression by reference to content.

And, in the identifying relation: form realises function, 

the identity either encodes function by reference to form,

or it decodes form by reference to function.

And, in the identifying relation: structure realises system, 

the identity either encodes system by reference to structure,

or it decodes structure by reference to system.

Distinguishing Realisation From Instantiation

Realisation and instantiation are clearly defined by being characterised in terms of the two types of relational processes.

(1) realisation is an [intensive] identifying relation:

the lower stratum (Token) realises the higher stratum (Value).

The difference is one of (symbolic) abstraction or signification.

eg coin as Token represents two dollars as Value.

These are two levels of abstraction of the same phenomenon.

(2) instantiation is an [intensive] attributive relation:

a text as Carrier (instance/member/specimen) of English language system as Attribute (class).

eg Tony Abbott as Carrier (instance/member/specimen) of Homo sapiens as Attribute (biological category).

Here’s a way to check usage:

If the relation being described crosses strata, then it is realisation.

Instantiation does not cross strata:

the system of semantics is ‘instantiated’ by the semantics of the text;

the system of lexicogrammar is ‘instantiated’ by the lexicogrammar of the text;

the system of phonology is ‘instantiated’ by the phonology of the text.

And at the level of context:

the system of context of culture is ‘instantiated’ by the context of situation.

Saussure, Hjelmslev And The Problem Of Realisation

Halliday & Matthiessen (1999: 510):

… we do not yet fully understand the nature of the relationship that is the semiotic analogue of the "cause : effect" of classical physics: this is the problem of realisation. It is true that Saussure, and even more Hjelmslev, took important strides towards an understanding; but we are still arguing about what Saussure really meant (to us it seems that he had not clearly separated the two concepts of instantiation and realisation), and Hjelmslev has been largely ignored — Sydney Lamb (eg 1966a, b) is almost the only person who has tried to follow through his achievements.

SFL's Architecture Of Language Classified By SFL Relations

A. system networks

i. delicacy: elaboration

ii. disjunction: extension: alternative

iii. conjunction: extension: addition

iv. entry condition: enhancement: condition

B. rank scale: extension: composition (Halliday & Matthiessen 1999: 146)

C. realisation: elaboration + identifying (Halliday & Matthiessen 1999: 145)

1. higher stratum realised by lower stratum [stratification]

2. system realised by structure [axis]

3. function realised by form; eg clause rank function structure realised by group rank syntagm

D. instantiation cline: elaboration + attributive (Halliday & Matthiessen 1999: 145)


P.S. The pedagogical advantage of understanding SFL's architecture of language in these very precise ways is that it enables the learner to immediately identify the bluffers in the SFL community who don't understand the theory — but whose confident bullying might suggest otherwise — so that the learner doesn't waste time trying to accommodate their misunderstandings.

Why ‘Realisation’ Applies To Both Strata And Rank And Where The Difference Lies

The overall architecture of SFL theory can be understood in terms of theoretical constructs within the model, namely: relational processes (identifying and attributive) and logical semantic relations (expansion and projection).

‘Realise’ functions as an intensive identifying process, which means that it combines ‘identifying’ with ‘elaboration’.

The term ‘realisation’ is used wherever there is an intensive identifying (token-value) relation in the theory. eg between system and structure on a given stratum, between strata, between function and form in the rank scale.

Stratal Hierarchy:

In the case of strata, a lower stratum realises a higher stratum, and the relation between them is thus identifying + elaboration.


Rank Scale:

The rank scale, on the other hand, is organised in terms of composition, which is a subtype of extension.

‘Realise’ is used on the rank scale to relate the function of a higher rank to the form of a lower rank (eg Process is realised by verbal group). This relation between function and form is thus also identifying + elaboration.


Similarity:

The similarity thus lies in elaboration + identifying being an organising principle for both stratification and the rank scale.


Difference:

The difference lies in the fact that, whereas stratification involves only elaboration + identifying, the rank scale combines extension (relation between forms) with elaboration + identifying (relation between function and form).

Projection Vs Realisation

Projection is a logical relation between the material order of experience and the semiotic order of experience — between a macrophenomenon (a senser sensing or a sayer saying) and a metaphenomenon (an idea or locution).

Realisation is both a logical relation and an experiential relation.  

As a logical relation, it is elaboration, a type of expansion.  

As an experiential relation, it is one of symbolic identity, a type of identifying relation.  

Realisation is an ideational relation between different levels of symbolic abstraction.