Fontaine (2017: 5, 6):
The relationship of context and language through realisation and instantiation is shown in Fig. 2, taken from Halliday (1991).
Matthiessen (2015:34) explains that in Fig. 2, “situation type has the same location as context of culture (and context of situation) in terms of the hierarchy of stratification, but they are instead differentiated in terms of the cline of instantiation: context of culture is located at the potential pole, context of situation at the instance pole”.
Blogger Comments:
[1] To be clear, context and language are related by realisation, but not through instantiation, which is the relation between potential and instance, as Figure 2 illustrates.
[2] To be clear, this figure, adapted from Halliday, is potentially misleading, since it locates different perspectives of the same mid-point on the cline of instantiation as different locations on the cline of instantiation.
That is, cultural domain and situation type are not different points on the cline of instantiation, they are different perspectives on the same point: cultural domain takes the perspective of the potential pole of the cline of instantiation, whereas situation type takes the perspective of the instance pole of the cline of instantiation.
Likewise, register and text type are not different points on the cline of instantiation, they are different perspectives on the same point: register takes the perspective of the potential pole of the cline of instantiation, whereas text type takes the perspective of the instance pole of the cline of instantiation.
Halliday & Matthiessen (1999: 384):
