Matthiessen (1995: 33):
Semantics is the interface between the linguistic system and the higher-level systems of the context in which language is embedded. The relationship between context and language is of the realisational kind; that is, context is stratified above language and is thus realised by language.
This means that context determines systems in language; but it is also construed by them. The relationship between context and language is one of dialogic exchange.
From the perspective of the instantial text, this means that selections in the development of the text are influenced by context; but at the same time, these selections contribute not only to maintaining the context but also to constructing it.
Blogger Comments:
To be clear, here Matthiessen is consistent with Halliday (1978), so the inconsistencies identified below are in Halliday's model, not in Matthiessen's understanding of it.
[1] To be clear, if the relation between context and language is one of realisation, then the question arises as to whether the lower level of symbolic abstraction can be embedded in a higher level. For example, is phonology embedded in lexicogrammar, and lexicogrammar embedded in semantics?
[2] To be clear, if the relation between context and language is realisation, then context does not determine systems in language, since the relation between them is intensive identity (elaborating), whereas 'determine' is a causal relation: one of circumstantial identity (enhancing).
[3] To be clear, if the relation between context and language is realisation, then the relationship between them cannot be one of dialogic exchange, because there can be no dialogic exchange between different levels of abstraction. For example, there can be no dialogic exchange between Hamlet and the actor playing him.
[4] To be clear, if the relation between context and language is realisation, then selections in the development of the text are not influenced by context. This is because the relation between them is elaborating (intensive identity), not enhancing (circumstantial identity), which means that the unfolding of context and language is the same process viewed at different levels of symbolic abstraction.
Instead, if the relation between context and language is one of realisation, then, in logogenesis, earlier selections probabilise later selections, and this can be viewed at each level of symbolic abstraction: context and language. That is, the influence is intra-stratal, not inter-stratal.