Why Dependency Relations Are Undesirable In Fawcett's Model Of Syntax

Fawcett (2010: 249):

However, it can be shown that it is not in fact necessary — nor even desirable — to model sister dependency relations in syntax. As I pointed out in Section 10.3.3 of Chapter 10, the supposed 'dependency' of a "modifier' on the "head' on a unit (e.g., in a nominal group) is a 'second order' concept, and ultimately an uninsightful one. In a SF grammar the relationship between the two elements is more appropriately seen as an indirect one, because each element realises its own aspect of the meaning of a referent, and the relationship is therefore at the level of meaning rather than form. In other words, in a SF grammar, any relationship of apparent 'syntactic sister dependency' is already expressed, in a natural manner, in the dependency relations by which one system is dependent on another in the system network of the language's meaning potential. For the systemic grammarian this is the true location of dependence (or 'dependency').

Blogger Comments:

[1] This is misleading. On the one hand, Fawcett's argument is invalid because it relies on his own misunderstandings of theory; see further below. On the other hand, interdependency is valuable for its explanatory potential across all grammatical ranks. This is demonstrated at group rank, for example, where the logical structure of the verbal group realises the system of TENSE in English. Halliday (1994: 198-9):

[2] See the examination of Section 10.3.3 — Confusing Structure With (Transcendent) Ideational Denotation — for a dissection of Fawcett's first-stated misunderstandings on this matter.

[3] Here Fawcett repeats his confusion of logical structure (dependency relations) with ideational denotation ("each element realises its own aspect of the meaning of a referent").

[4] To be clear, on the one hand, 'meaning and form' are levels in Fawcett's model (Figure 4), not in SFL Theory. On the other hand, in SFL Theory, dependency relations obtain at both levels of content, semantics and lexicogrammar — with mismatches constituting instances of grammatical metaphor — and are modelled in systems that specify their structural realisations.

[5] This is misleading. In SFL Theory, dependency relations are modelled as systems, not by dependency relations between systems. For example, 

Strictly speaking, system networks do not construe dependency relations between systems. However, it could be said that entry to a system "depends on" the selection of its entry condition.