Coherence

[Bill Mann]

Fellow RST-list subscribers:

James Cornish in his message on coherence mentions cohesion, including the
cornerstone work of Halliday and Hasan, "Cohesion in English."

As we try to identify coherence I think it will be useful to make a strong
distinction between coherence and cohesion.

Cohesion has to do with how particular texts in effect have links within them,
from one part to another. Various languages have different <<cohesive devices>>
for expressing such links.  In English these include repeated words, names and
phrases, repeated mention (where the same is evoked, but the evoking words are
different), anaphora (now these categories obviously overlap) including zero
anaphora, pronouns, titles ("Your Honor"), temporal and locative orientations
such as "earlier", "here" and "now" and many more.  Cases of cohesion cannot be
discussed without somehow identifying the language in which they are expressed.
Cohesive devices can be compared across languages.

Coherence has to do with an impression of wholeness.  It is expected of texts,
but not text fragments.

Cohesion generally contributes to the impression that a text is coherent.
Cohesion is also nearly unavoidable, just because of continuities of subject
matter or intent.  Coherent texts without any of the well known cohesive devices
can be constructed, but they are extremely hard to find.

Closely related to cohesion is intertextuality, where the links are to other
texts.  Allusion and repetition of form are often involved. ("Ask not what RST
can do for you, but what you can do for RST."  John not quite Kennedy.)

RST analysis uses cohesive links as evidence, but RST has little or nothing to
say about cohesion itself.  It is "pre-realizational,"  whereas cohesion is not.

On coherence, I don't think I have said anything above that I did not say
earlier, but perhaps this will contribute toward clearer discussion.

Bill Mann