Question 1a: Cohesive chains (similarity and identity)
For a series of linguistic signs to
be perceived as text (“language that is functional” (Halliday 1989: 10)), it
must have unity (Hasan 1989a: 52).
According to Hasan, one “source of textual unity” is texture (1989b: 70), which is constituted by “semantic relations
between ... individual messages” of a text (ibid.:
71). Semantic relations are realized formally in a text by cohesive devices (Hasan 1989b: e.g. 75, 79–80); provided that
cohesive devices are interpreted as cohesive by the reader/listener (Fries
2004: 22) – i.e., they are understood – they will form cohesive ties between items in a text (Hasan 1989b: e.g. 73, 75). Whenever
“a set of items” are semantically related – or tied – throughout the whole or a
part of a text, they form a cohesive
chain (Hasan 1989b: 84). A text will normally consist of several cohesive
chains; these will normally interact. According to Fries (paraphrasing Hasan),
“two chains of equivalent terms interact if the same experiential relation is
reiterated between their members” (Fries 2004: 27). As I understand Hasan, the relative
strength and comprehensiveness of a text’s chain interaction determines its degree
of cohesive harmony (1989b: 93–4); this,
finally, is a condition (but, according to Fries (2004: 24), not always
necessary) for our experience of a text as being coherent (Hasan 1989b: 94).
