Halliday & Matthiessen (2014: 700-1):
But the notion of interpersonal projection is not, in fact, limited to modal assessment. Consider the short persuasive text in Text 10-5:
Text 10-5: Exploring – arguing: open letter appealing to members of an organisation [Text 6]
I don’t believe that endorsing the Nuclear Freeze initiative is the right step for California Common Cause. Tempting as it may be, we shouldn’t embrace every popular issue that comes along. When we do so we use precious limited resources where other players with superior resources are already doing an adequate job. Rather, I think we will be stronger and more effective if we stick to those issues of governmental structure and process, broadly defined, that have formed the core of our agenda for years. Open government, campaign finance reform, and fighting the special interests and big money – these are our kinds of issues.
Let’s be clear: I personally favour the initiative and ardently support disarmament negotiations to reduce the risk of war. But I don’t think endorsing a specific freeze proposal is appropriate for CCC. We should limit our involvement in defence and weaponry to matters of process, such as exposing the weapons industry’s influence on the political process. Therefore, I urge you to vote against a CCC endorsement of the nuclear freeze initiative.
Expressions of modulation are bolded and expressions of modalisation are italicised; metaphorical expressions are underlined. Subjective assessment of modality permeates the text, like a prosody. In the case of modalisation, it is largely explicit; in the case of modulation, it is implicit until the very last clause. This clause realises the nucleus of the whole text; it is here that the key proposal is presented with a nuclear punch… .
But what is the key proposal? One variant of I urge you to vote ... is you must vote ..., the two being relatable as explicit and implicit variants of subjective, high modulations of the type obligation. However, we can take one step further in the analysis. What the author is saying is Vote against ..., which is an ‘imperative’ clause – the congruent realisation of a proposal of the subtype ‘command’. This indicates the connection between ‘imperative’ clauses and modulation, which is why modulation was characterised as the ‘imperative type’ of modality. On the one hand, an ‘imperative’ clause imposes an obligation; on the other hand, the imperative tag checks the addressee’s inclination to comply (will you?). But the example also illustrates the connection between mood and projection.