Seriously Misunderstanding Marked And Unmarked Theme

Martin & Rose (2007: 190-1):

The next step is to highlight Themes — which in writing is basically everything up to and including the participant that functions as the Subject of the clause. …

So the most common choice for the Theme of a clause is the Subject. Ideational meaning that comes before the Subject is referred to as marked Theme, and has a different discourse function from the ordinary Subject/Theme … .

Blogger Comments:

To be clear, this widespread misunderstanding of Theme derives from Martin (1992: 435):

…in English declaratives, unmarked topical Theme is conflated with Subject, whereas marked topical Theme precedes it.

Applying Martin's misunderstanding of Halliday, a clause can consist solely of topical Themes, such that there are multiple points of departure for the clause as message, but no actual body of the message (Rheme) to depart into.  For example:

Blessed	are		the cheesemakers
Theme: marked	Theme: marked		Theme: unmarked
Attribute	Process: relational		Carrier
Complement	Predicator	Finite	Subject
Residue		Mood

Sad	therefore	in his view	is		one way to describe it
Theme: marked	?	Theme: marked	Theme: marked		Theme: unmarked
Attribute		Angle	Process: relational		Carrier
Complement	conjunctive Adjunct	circumstantial Adjunct	Predicator	Finite	Subject
Res-		-idue		Mood

In contrast, Halliday & Matthiessen (2014: 91) provide the general principle:

As a general guide to start off with, we shall say that the Theme of a clause is the first group or phrase that has some function in the experiential structure of the clause, i.e. that functions as a participant, a circumstance or the process.

and stipulate (p128) that markedness depends on mood:

The systemic value of ‘unmarked’ and ‘marked’ theme depends on the mood selection…

It is for declarative clauses that the Subject is the unmarked Theme (p97):

In a declarative clause, the typical pattern is one in which Theme is conflated with Subject; …. We shall refer to the mapping of Theme on to Subject as the unmarked Theme of a declarative clause. The Subject is the element that is chosen as Theme unless there is good reason for choosing something else.

But if Subject is not Theme, the selected Theme is a marked Theme (p98):

A Theme that is something other than the Subject, in a declarative clause, we shall refer to as a marked theme. The most usual form of marked Theme is an adverbial group, e.g. today, suddenly, somewhat distractedly, or prepositional phrase, e.g. at night, in the corner, without any warning functioning as Adjunct in the clause. Least likely to be thematic is a Complement, which is a nominal group that is not functioning as Subject – something that could have been a Subject but is not…

Most importantly, where the Subject is not selected as Theme, it is part of the Rheme (p105):

When some other element comes first, it constitutes a ‘marked’ choice of Theme; such marked Themes usually either express some kind of setting for the clause or carry a feature of contrast. Note that in such instances the element that would have been the unmarked choice as Theme is now part of the Rheme.

A clause has, at most, one topical Theme: either unmarked or marked.