Reasons For Adopting A Systemic Perspective

Halliday & Matthiessen (2014: 20):

… one is that languages evolve — they are not designed, and evolved systems cannot be explained simply as the sum of their parts. Our traditional compositional thinking about language needs to be, if not replaced by, at least complemented by a ‘systems’ thinking whereby we seek to understand the nature and the dynamic of a semiotic system as a whole.

The Commonality Of Biosemiosis And Sociosemiosis

Halliday & Matthiessen (1999: 607):

… it is the fact that language and the perceptual systems share a common “realisation” in neural networks and neural processes that enables language to function as a dynamic open system, one that persists in time by constantly being modified through ongoing exchanges with its environment.