Halliday & Matthiessen (1999: 68):
Naturally our categorisation tends to be oriented towards phenomena on a particular scale, those that lie within the bandwidth of those phenomena which are most readily accessible to our senses and which we engage with in day to day existence. This is the realm which impinges most closely on our physical, biological and social being; the semantic system has evolved with this as its primary semogenic environment. Lying beyond this are the micro- and the macro-worlds which are accessible to us only by instrument and by inference.
It is a powerful demonstration of the potential of the semantic system that it readily fashions new meanings that model these experientially remote domains. What is less obvious, perhaps, is that it has had to be equally resourceful in modelling the ongoing changes in our social environment, where both the overall social order and our local interpersonal networks are constantly being modified and realigned.