Didactics of Translation: Text in Context

Thematic structure in Halliday’s approach:

Since the clause as a message has a certain interactional organization, two concepts have been put forward in order to unravel the threads of this interaction: these are theme and rheme. Theme refers to the subject matter of the clause and does two things:

1. 
   connecting back to previous stretches of discourse and thereby maintaining a coherent point of view
   
2. 
   connecting forward and contributing to the development of later stretches. (Baker 1992: 121).
   

As for the rheme, which usually occurs after theme, this refers to what the speaker/writer says about the subject matter; as such, it is considered highly important. According to Baker (Ibid: 123),
there tends to be a very high correlation between theme/rheme and subject/predicate in the Hallidayan model.
This correlation, however, does not extend to the case of marked themes (Ibid).
Hatim and Mason (1990: 212) maintain that the concepts theme/rheme are very important for texture:
one basic aspect of texture which works in harness with cohesion is theme-rheme arrangement.
It should, however, be pointed out that the theme/rheme concepts are not strictly the prerogative of the sentence. In fact, Baker states that
the theme/rheme distinction is text-based. Its real value does not lie in explaining the structure of individual sentences but rather in shedding light on a number of important areas which control information flow. (Baker 1992: 124)

In the same vein, Hatim and Mason state that “thematicity or givenness is a discoursal phenomenon rather than merely a property of the sentence” (1990: 212).

To show that the theme-rheme distinction is a discoursal (i.e. textual) phenomenon and not merely a sentence-based matter, one has only to look at the notions of acceptability and text organization and development. Thus, with regard to the notion of acceptability, theme and rheme can be used to explain why a given stretch of text seems acceptable while other parts are not. Sequences of sentences which are grammatical are not sufficient in themselves to guarantee acceptability. Although a text may be well-formed grammatically, it can be ill-formed as far as its thematic structure is concerned, giving us an unacceptable text. The following example by Halliday expresses this situation very clearly:
Now comes the President here. It’s the window he’s stepping through to wave to the crowd. On his victory, his opponent congratulates him. “Gentlemen and ladies. That you are confident in me honours me…” (1978: 134)
This text is inacceptable because there are no links between the themes of the different clauses or between their rhemes. As a result, there is a lack of a coherent point of view which results in a text that is dislocated and disjointed.
As far as text organization and development are concerned, the theme- rheme distinction can be resorted to in order to highlight particular methods of organizing and developing a text. It has been noted, for example, that certain types of texts consistently thematize certain sentence elements which as a sequence take on an organizational role and provide a method of text development. Travel brochures, for instance, where place adjuncts are thematized are often given to illustrate the point. The impact of adopting such a method of text organization and development on text interpretation is not insignificant. According to Fries (1983), cited in Baker (1992: 129):
If the themes of the sentences of a paragraph refer to one semantic field (say location, parts of some object…) then that semantic field will be perceived as the method of development of the paragraph. If no common semantic element runs through the themes of the sentences of a paragraph, then no simple method of development will be perceived.

2.