The formal introduction of discourse topics, for example, typically has them occurring in the information- structure focus of the sentence §3.5.1.
Since addressees generally assume that the text is intended to be coherent and since theme is a primary coherence strategy §2.2.5, one way to evaluate a potential theme is in its payoff for coherence:
“Those inferences that produce the most coherent discourse for the least cognitive effort are the most likely to reveal the author’s theme” Bruce 2003:176f.. Thus, if two potential themes produce the same
degree of coherence but one requires less effort, it is more likely to be perceived as theme; or if two potential themes require the same effort but one produces more obvious coherence, it is more likely to be
perceived as theme.
In assessing cognitive effort, the addressee must take into account external as well as internal contextualization §2.2.1. In particular, if a potential theme is implausible on text-external criteria the
processing effort is high, even though text-internal criteria may point to it. Text-external knowledge and expectations—for example, what the addressee knows about the speaker, about the situation being
described, about the world—will influence her perceptions of themes §3.4.4. One example of this came out when a particular verse was being checked for comprehension in Mbyá Guarani, 2 Corinthians 10:4:
“The weapons of our warfare are not of the flesh, but divinely powerful for the destruction of fortresses.” When the informant was asked what he understood of that verse, he replied that that the apostle Paul
wasnt likely talking about tearing down physical fortresses. When asked why he thought that, he said that the Bible—and he didn’t know much about it at that point—isn’t about tearing things down. “Any
conceptually represented information available to the addressee can be used as a premise in this inferential process” Sperber and Wilson 1995:65.
3.4.4 Conceptual inclusion between themes
In §2.2.5, the head of a schema was defined as a concept which the schema and each of its steps “aim to establish.” We noted, for example, that an argumentational schema “argues for” a proposition: the steps
in its schema support it in the role of reason, grounds, cause, etc. They support it in a more direct way than they could be said to support a topic or other nonpropositional theme. We see this in the interview
with the barber Appendix F, line 01: Most of your new barbers today, actually there isn’t too many taking it up. Allowing for the fact that the speaker did not here make use of the notion expressed by most
of, we still recognize NEW BARBERS TODAY as a topic for the excerpt. The different steps in the schema of Figure 8, however, do not support the topic as such, but the proposition there isn’t too many
taking it up. Since the schema is argumentational, it supports a propositional head. But the schema has a topic as well.
Since the coherence of a discourse space depends heavily on having a theme, multiple themes could put coherence at risk unless they are constrained in some way. One way to constrain multiple themes
seems to involve
CONCEPTUAL INCLUSION
: one theme is conceptually included in another if it is a complement of the other, elaborating a “salient substructure” of it Langacker 2001:21. In the texts we
have examined, whenever a space has a topic and a goal, the topic is a complement of the goal the topic is the participant who has the goal; and when there is a macropredication, it includes other themes as
complements a macropredication summarizes what the unit says about another theme. Thus we get the following inclusion chain:
topic ⊂ goal ⊂ macropredication situation ⊂ macropredication
Figure 16: Conceptual inclusion between themes of a discourse space
Situational themes do not have a fixed order in relation to topics and goals. In general, they seem to include other themes that are presented before it in the discourse unit. However, they are always included
in a macropredication.
The conceptual inclusion relations of Figure 15 apparently are a common influence on the order in which discourse themes are presented in a text. We return to this idea in §3.4.6.
Ignoring until §3.4.5 the possibility of a space having multiple themes the same kind, it appears that, always or nearly always, a discourse space with multiple themes will have one maximally inclusive theme.
Moreover, it appears that for a discourse space with multiple themes, the maximally inclusive theme is the head of its schema. These are empirical observations. We now see how they work out in specific texts,
noting what themes there are, whether heads of schemas are maximally inclusive, and in what ways they “head up” their schemas. They remain to be studied in a variety of other texts, genres, and languages.
One example has already been mentioned, the interview with the barber Appendix F. As noted above, there are two themes, a topic and a macropredication. The macropredication includes the topic and
is head of the argumentational schema. A very different kind of text is an encyclopedia article on England “England” 1998. It has the main
sections and subsections, as shown in Figure 17:
Introduction The land
Physiography and
terrain Climate
Natural resources
Plants and
animals
Population
Ethnicity Population
characteristics Political
divisions Principal
cities Religion
Education Culture
English law
Economy and
government
History
goes up to Union with Scotland in 1707; continues in another article, “Great Britain”
Figure 17: Outline of encyclopedia article on England
If we understand the steps in the global schema to be the bolded headings listed above, then the global schema is descriptive and partitive, simply a listing of aspects that are covered in the article. The only
global theme is England, a topic.
Those texts are two extremes, with heads on opposite ends of the scale of conceptual inclusion Figure 16. Now we consider texts with situation and goal heads, neither of which is common; both
situations and goals commonly occur as only provisional themes.
Example text 26: Acts 5:12–16 New American Standard Bible 1995
12a At the hands of the apostles many signs and wonders were taking place among the people; 12b and they were all with one accord in Solomon’s portico.
13a But none of the rest dared to associate with them; 13b however, the people held them in high esteem.
14
And all the more believers in the Lord, multitudes of men and women, were constantly added to their number,
15 to such an extent that they even carried the sick out into the streets and laid them on cots
and pallets, so that when Peter came by at least his shadow might fall on any one of them. 16a Also the people from the cities in the vicinity of Jerusalem were coming together, bringing
people who were sick or afflicted with unclean spirits, 16b and they were all being healed.
This paragraph is descriptive; in the Greek, all verbs in main clauses are imperfective. It appears to describe various aspects of the life of the early church in Jerusalem at a particular historical moment.
According to one commentator, “We may fault [Luke] for crowding too much into his summary paragraph or for arranging it in a somewhat jumbled chronological sequence. But the course he plots…is
not too difficult to follow” Longenecker 1981:316f.. The passage includes miracles being done by the apostles 12a, the disciples meeting together 12b, a respectful distancing by the general populace 13,
numerical growth 14, sick being brought, from Jerusalem and outside, and being healed 15–16. There is no obvious macropredication or goal. The church itself could be a possible topic, being referred to by
pronouns they and them in lines 12b–15, although there are references to other groups as well. The most obvious theme seems to be situational; it is difficult to summarize, but that seems to be common with
situational themes. The situation heads the descriptive schema, which is partitive in the sense that different aspects of the situation are successively described.
Texts with final goal themes may be rare Figure 15 lists no such schema types, provisional goal themes are extremely common. One example is “Stone soup” Appendix D, which has two global
provisional themes: the poor man as topic and his goal of obtaining food §2.2.7. The goal is the more inclusive theme and the head of its provisional schema for most of the text.
In each of these examples, it turns out that the maximally inclusive theme of the discourse space is also the head of its schema. To the extent that this turns out to be true for texts in general, and assuming
that multiple themes of the same kind make no problems for coherence §3.4.5, this seems to provide an answer to the question about coherence: multiple themes do not make a discourse unit noncoherent
because the head of the schema includes all other themes.
It appears that heads of schemas are not only the maximally inclusive theme, but they tend to have cumulative content as a text is processed. For this reason, final heads perhaps in every case include
intermediate heads. In Figure 15, where final heads differ from intermediate heads, the final head is in every case a macropredication and the intermediate head is a less inclusive goal or situation. In “Stone
soup,” the intermediate goal head is replaced by a final macropredication, that the poor man obtained food by using his wits.
3.4.5 Multiple themes of the same kind
