Fawcett's Problem With Realisation Rules In System Networks

Fawcett (2010: 66): 

The initially attractive idea that this is intended to represent is that each feature in a system network contributes to the structure that is being built, and that each such rule should 'fire' as soon as its feature is chosen. Representing the realisation rules in this way, then, fits in nicely with the idea that the lexicogrammar is simply all at one level of language — and this is precisely the concept that is required in Halliday's second approach to meaning. 

Ultimately, however, this approach is unworkable. The problem with it is that it depends on the concept that there are no exceptions to the 'typical' effect of choosing a given feature. But if the 'firing' of the realisation rule is dependent upon the co-selection of another feature (as is often the case), it cannot be allowed to fire as soon as the feature is chosen, because a 'conditional feature' may also be selected in another part of the network which might demand that the realisation should be different.

Blogger Comments:

[1] To be clear, in SFL theory, the system of a grammatical rank is realised by the structure of a rank unit.  This is the axial dimension: the relation between the paradigmatic and syntagmatic axes.

On the other hand, the selection of a feature entails the activation of its realisation statements.  This is the dimension of instantiation: the relation between potential and instance.

[2] As previously explained, Halliday has only had one "approach to meaning" in devising SFL theory.  It merely suits Fawcett's argument to believe otherwise.

[3] To be clear, the problems that Fawcett identifies here only arise if there are problems with (the wiring and/or features of) the system network itself.  It will be seen in the next post that Fawcett exemplifies "the problem", not by critiquing one of Halliday's systems, but by reference to one of his own (problematic) systems.