Martin (1992: 228):
In spite of the usefulness of the paraphrase test to tease out incongruent realisations for internal connections, distinguishing internal from external additive, comparative and concessive relations can be difficult, since with these relations the difference between constructing text and constructing field is not always clear.
The difference between internal and external relations is not the difference between constructing text and constructing field.
On the one hand, the contrast between internal and external conjunctive relations is a metafunctional contrast, interpersonal vs experiential, in the meanings being conjoined.
- Internal conjunction sets up an expansion relation between the interpersonal meanings, propositions and proposals, realised by the clauses, whereas
- external conjunction sets up an expansion relation the experiential meanings, figures, realised by the clauses.
On the other hand, the contrast between constructing text and constructing field is the contrast between semogenesis and stratification. 'Constructing text' is logogenesis — language unfolding at the instance pole of the cline of instantiation — whereas 'field' is the ideational dimension of context — the culture as semiotic system — as realised by language.