Agent And Voice

Martin & Rose (2007: 91):

In addition to the Medium, one or two other participants may be involved in the process, including Agent, Beneficiary and various types of Range. An Agent instigates the process, which affects the Medium in some way:

These effective clauses can be reversed in passive form, with the Agent as a ‘by phrase’:

Blogger Comments:

[1] Trivially, Agent, Beneficiary and Range are three types of participant, but less trivially, all three may be involved in a single Process, as in:

the minister	made	Bach	play	organ	for the choir
Agent	Pro-	Medium	-cess	Range	Beneficiary

[2] To be clear, Agent is the external cause of a Process, construed as a participant (Halliday & Matthiessen 2014: 336).  For example:

meaning	is realised	by wording
Medium Value	Process	Agent Token

Having here identified the Agent as the participant that instigates a Process, the authors later (p94) present the Medium as instigating a Process.

[3] To be clear, an Agent causes the actualisation of a Process through a Medium.

[4] Trivially, in SFL theory, this is termed 'receptive' at clause rank, with passive' being reserved for the verbal group.  Non-trivially, the choice of voice serves a textual function, not an experiential function; see Halliday & Matthiessen (2014: 348). That is, the two variants construe the same experience, but differ in which experiential function is made Theme and (unmarked) New.

Importantly, the reason Martin & Rose introduce this spurious variable here, is that they are preparing to misinterpret Halliday's ergative model of clause nuclearity in terms of what can and cannot be omitted for textual reasons.  That is, as will be seen, their model of nuclear relations, as experiential discourse semantics, is based on a confusion of the experiential metafunction with the textual.