Critique on Theme Theory of Systemic Functional Linguistics

    This essay is a critique on the theme theory, one of the systems of Textual Function in Systemic Functional Linguistics (SFL). The paper first demonstrates the basic theories from which SFL is originated and developed, then gives a brief introduction to the development of SFL from form to meaning and context. The theme theory is in line with the development of SFL from focusing on formalization to concerning the text and context. 
    According to Halliday, the Theme contains one, and only one, of these experiential elements, Halliday makes distinction between Marked Theme and Unmarked Theme. When the subject of a clause assumes the Theme, it is Ummarked Theme. When the circumstantial element as adverbial group or prepositional phrase assumes the Theme, it is marked. Unmarked Theme usually coincides with the subject of the clause which arouses few debates and the debates focus on the boundary of Marked Theme. Some scholars argue that the Thematic structure should extend to include the subject of the clause and Berry summarizes ten hypotheses regarding the boundary of the Theme. However, the author thinks that Halliday’s Theme theory is easy to operate in reality and still dominates in present-day’s Theme Theory.
    According to the content of the Theme and the functions it performs, Theme can be divided into three categories: experiential, interpersonal and textual. When the thematic structure only includes one experiential element, it is Simple Theme. When the thematic structure consists of interpersonal and/or textual elements together with the experiential one, it becomes the Multiple Theme. In clause complex, there will appear clause theme. Debates appear on Multiple Theme and Simple Theme when concerning Halliday’s idea that Theme is a process of choices based on the communicative purposes. There are some exceptions proving that Theme is not totally a process of choosing. The author believes that more research will be needed in regard of Halliday’s choosing theory.  
I INTRODUCTION
A.  Theory Basis for SFL
    Halliday, born 13th April 1925 in England, obtained BA honours degree in Modern Chinese Language and Literature (Mandarin) in the University of London. 1947-1949, He studied under the supervision of Luo Changpei at Peking University in China for Chinese phonology, lexicography and comparative historical nlinguistics. In order to study modern Chinese dialects, he transferred to Lingnan University under the supervision of Wang Li in 1950. He was admitted by Cambridge University as PhD student when back to London in 1949, under the supervision of J.R. Firth. He was awarded PhD on the study of a late fourteenth century Chinese text with the title The Language of the Chinese “Secret History of the Mongols”. 
    Firth thinks that meaning is very important in langue, so is social context where parole is produced. Influenced by Malinowski, an anthropology professor in the London School of Economics and Political Science, Firth aims to establish a linguistic theory based on context of situation. But he does not set a complete theoretical framework. Halliday gets the idea of system and structure from Firth and the concept of context from Malinowski. All these formed the basic ideas and foundation of SFL.
B.  A Brief Review on Halliday’s SFL
    Halliday, as student of Firth, the founder of London School in linguistics, develops Firth’s linguistic ideas into theories. In 1956, Halliday publishes Grammatical categories in Modern Chinese, in which he puts forwards three grammatical categories: unit, element and class, with system as a subcategory of class. This lays a preliminary frame to analyze the relationship between units in languages. In 1961, in Categories of the theory of grammar, Halliday makes some revisions and outlined four grammatical categories (unit, structure, class and system) and three scales (rank, exponence and delicacy), in which system becomes a category rather than a subcategory affiliated to class. This paper establishes scales and grammatical categories, which constitutes Firth’s ideas of structure and system and is the first development stage of SFL. 
    In 1966, the publication of Some notes on ‘deep’ grammar makes the substitution of scales and categories by systemic grammar. In this paper, Halliday makes distinction between surface aspect and deep aspect of language structures and demonstrates that structure represents deep syntagmatic relationship while system stands for deep paradigmatic relationship. In 1967, discussions of syntagmatic relationship and paradigmatic relationship begin to connect with functional components. In 1968, Halliday puts forward four functions: experimental function, logical function, textual function and interpersonal function. In 1970, the four metafunctions are adjusted as ideational function, textual function and interpersonal function, which are known as the three metafunctions of Systemic Functional Grammar. 
    The publication of Halliday’s An Introduction to Functional Grammar in 1985 marks the maturing of functional grammar while Matthiessen’s Lexciogrammatical Cartography: English Systems in 1995 represents the systemic part of SFL. Construing Experience Through Meaning: A Language-based Approach to Cognition punlished in 1999 by Halliday and Matthiessen describes human experiences from meaning instead of knowing. 
    As its name implies, SFL focuses on the functions of language while system refers to the ways in which the functions are organized. “For Halliday, language is one type of semiotic system, which simply means that language is a system (or that it is organized systemically) and it represents a resource for speakers so that they can create meaning”.(Fontaine, 2012, p.5) However, “the primary driving force in language use is function” (p.5). So function plays an important place in SFL. “The systemic functional account of language contemplates three types of meaning, or metafuntions, at the level of the clause: ideational, interpersonal, and textual” (Ana Elina Martinez-Insua, 2019, p.218). Theme is one of the three systems in textual function.
II Theme Theory and Related Discussions
A.  Origin and Definitions for Theme 
    More than 2000 years ago, Greek philosophers Plato and Aristotle notice that human beings usually name an entity and then give a description about it when making judgments, from which the concept of dichotomy appears and is then introduced into the discipline of linguistics. Late 19th century, French scholar H. Weil discovers that the basic rule of human communication is a process from a given message to a target text, during which there usually exist two forms: starting point and statement. Starting point refers to the part at the beginning of a text and the rest part is statement. These theories laid solid foundations for theme-rheme theory in modern Linguistics. 
    The concept of theme is put forward in the 1930s by Mathesius, founder of Prague School, to refer to the starting point of discourse and the topic for discussion. In 1960s, Halliday borrowed the concept and introduced it into textual function of systemic functional grammar as theme system.
    Halliday has given a variety of descriptions for Theme in his works. In Notes on Transitivity and Theme in English (1967), there appear the following descriptions: “Basically, the theme is what comes first in the clause. “… ‘theme’ means ‘what I am talking about’ (or ‘what I am talking about now’)”. “The theme is what is being talked about, the point of departure for the clause as a message…”.(p.212)
    In Language Structure and Language Function (1970:161, cited by Guowen Huang, 2009), Halliday states that “The English clause consists of a ‘Theme’ and a ‘Rheme’… [ the Theme] is as it were the peg on which the message is hung… The Theme of the clause is the element which, in English, is put in first position …”
    In third version of An Introduction to Systemic Functional Grammar published in 2004, Halliday defined that “The Theme, however, functions as a message. A clause has meaning as a message, a quantum of information; the Theme is the point of departure for the message. It is the element the speaker selects for ‘grounding’ what he is going to say” (p.58) “The Theme is the element which serves as the point of departure of the message; it is that which locates and orients the clause within its context”. Besides, there also appear the following expressions: “The structure which carries this line of meaning [message meaning] is known as thematic structure.” “In English, as in many other languages, the clause is organized as a message by having a distinct status assigned to one part of it. One part of the clause is enunciated as the theme; this then combines with the remainder so that two parts together constitute a message.” (p. 64) “…, the Theme always starts from the beginning of the clause …. It is what sets the scene for the clause itself and positions it in relation to the unfolding text.” (p. 66)
    From the above description, we could see that in 1967 and 1970, the words such as meaning and context do not appear in the description for Theme. Theme is “the point of departure” as “a message”, which “is put in first position”. In 2004, besides being “the point of departure for message”, Theme also “locates and orients the clause within its context” and “carries this line of meaning”. It is obvious that the descriptions for or Theme (structure) are towards concerning meaning and context.
B.  Theme Hypothesis
    “While most systemicists acknowledge the influence of Halliday’s description of the concept of Theme, some scholars have suggested modification” (Martinez-Insua, A. E, 2019, p.219). Berry mentioned the following hypotheses regarding the defining in What is Theme - A(nother) Personal View (p. 29-31). 
    i) the first position hypothesis realized by first position in clause and the first ideational element realized by the part of the clause that extends up to and includes the first ideational element are thematic boundary proposed by Halliday; 
    ii) the subject hypothesis is what Enkvist proposed to include elements up to and including the Subject of a main clause;
    iii) the preverb hypothesis and the lexical verb hypothesis are proposed by Berry, I have mentioned the former at the end of Part B, while the latter means that the Theme “includes all parts of a main clause up to and including the lexical verb”; 
    iv) the auxiliary verb hypothesis proposed by Stainton suggests that auxiliary verbs, as well as what preceded them, should be included in the Theme;
    v) Matthiessen argued that ‘the thematic prominence of the clause gradually devreases as the clause unfolds’”, which means that “Theme-Rheme can be regarded as forming a continuum; the early part of a clause is clearly thematic, the later part of a clause clearly thematic, but the two shade into each other, it not being possible to say precisely where the boundary occurs.” Berry refers to this as the continuum hypothesis;
    vi) the overlapping hypothesis is another way to interpret Matthiessen’s views above, which means “… Theme ends and Theme begins, …the two overlap”. “Ravelli… suggesting that the thematic portion of a clause carries the main weight of the interpersonal and textual meaning, while the thematic portion of a clause carries the main weight of the ideational meaning. The two meet somewhere in the neighborhood of the verb.”
    Berry also mentioned the unusual position hypothesis and the main clause hypothesis. From the hypotheses above, we can see the complication of and hot debates on the Theme theory. Berry also mentioned that “Theme is a field in which one can never be entirely sure whether or not one is agreeing with someone else” (p.1). “Berry opens a line argument about how Theme can be identified. She evaluated the validity of up to eight hypotheses that go from the assumption that Theme is what occupies the first position of the clause, to the hypothesis that Theme-Rheme is a continuum and the thematic prominence of the clause decreases as it unfolds. Berry does not propose any of these hypotheses as the only plausible one for the determination of Theme, but rather highlights the need to consider both the clause and the discourse when trying to determine Theme. Berry opens the door to have different views of Theme depending on the ultimate purpose of the investigation one undertakes”(Martinez-Insua, A. E, 2019, p.219).
C.  Marked Theme and Unmarked Theme
    The Theme always starts from the beginning of the clause, which sets the scene for the clause and positions it in relation to the unfolding text. Generally speaking, the Theme of a clause is the first group or phrase that has some function in the experiential structure of the clause. Halliday makes distinctions between marked theme and unmarked theme. 
    (1) My son + played badminton yesterday.
    (2) Yesterday + son played badminton.
    Taking the above declarative clauses for example, when subject of a clause assumes the Theme, it is called Unmarked Theme, as in (1), my son in the clause is the Unmarked Theme. If adverbial group or prepositional phrase rather than the subject of a clause assume the Theme, it is Marked Theme. In 
    (2), yesterday is the Unmarked Theme. 
    (3) Do you + like playing Ping-Pong?
    (4) Which animal + do you like?
    (5) What + happened to you?
    (6) What you can do + is to focus on the task.
    (7) How clever + the boy is!
    (8) Do + it now. 
    In declarative clauses such as (1), Unmarked is realized by the Subject; in yes/no questions as (3), it is the finite verbal operator plus Subject; in wh-questions as (5), it is wh-word or group as in (5) and (6); in the exclamatory clause (7) and the imperative clause (8), it is the initial element of the clause.
    The boundary of Unmarked Theme usually will not arouse much debate among scholars. The contradictions concern clause (2), in which, according to Halliday, the Theme is “yesterday”. However, Berry (1996) argues that the participant “my son” as the subject of the clause is significant to the clause and should be included in the thematic structure. In Berry’s opinion, the elements before the predicative verb all belong to the Theme.
D.  Simple Theme, Multiple Theme and Clause Theme
    According to Halliday, “The principle relevant to the thematic structure is this: the Theme always contains one, and the only one, of these experiential elements. This means that the Theme of a clause ends with the first constituent that is participant, circumstance, or process.” (Halliday 1994/2000, cited by Hongyang Wang, 2009, p. 30) So the Theme must be assumed by experiential elements of the clause, which include the participant, process, or circumstance in the transitivity system. So in (1) and (2), the participant my son and the circumstance yesterday could assume the Theme, also Simple Theme. Halliday also puts forward the concept of Multiple Theme. He says “…the Theme extends from the beginning of the clause up to (and including) the first element that has a function in transitivity. This element is called the ‘topical Theme’; so we can see that the Theme of the clause consists of the topical Theme together with anything else that comes before it.” (Halliday 1994/2000, cited by Hongyang Wang, 2009, p. 30)
    (9) But the duke has given my aunt that teapot.
    (10) Interestingly, the duke has given my aunt that teapot.
    (11) But, interestingly, the duke has given my aunt that teapot.
    In (9)-(11), “But the duke”, “Interestingly, the duke”, “But, interestingly the duke” assume the Theme and the duke as the topical Theme in three clauses. In (9), “but” takes the textual meaning as structural cohesion; in (10), “interestingly” shows the interpersonal meaning as the comment. They are separately as Textual Theme and Interpersonal Theme. In (11), Textual Theme and Interpersonal with the Topical Theme combine together as Multiple Theme.
    (12) John likes basketball and Mary likes volleyball.
    (13) When I went into the room, he was doing homework.
    By referring Clause Theme, it means that a clause serves as the Theme. There are two types of clause-complex: paratactic and hypotactic. Paratactic clause complex refers to a combination of clauses with equal status, which is usually linked by and, while etc. Hypotactic clause complex consists of two or more unequal clause, such as clause complex linked by wh-clauses. (12) is a paratactic clause-complex while (13) a hypotactic one.
E. “No choice” in Theme-choosing Process
    Halliday says: “As a message structure… a clause consists of a Theme accompanied by a rheme, and the structure is expressed by the order-whatever is chosen as the Theme is put first” (Halliday, 1994/2000, cited by Hongyang Wang, 2009, p.30). “Users construe meanings by making choices from linguistic systems” (Ana Elina Martinez-Insua, 2019).
    From (1)-(2), it is obvious that theme is a process of choosing depending on the communication purposes. “My son” and “yesterday” all could assume the Theme, no matter which part is put first will not influence the syntactic meaning, but the emphasis and the focus of the clause will differ with different part assuming the Theme. This is perfect to explain the simple Theme in (1) and (2), in which the structure element with experiential meaning is chosen to be put at the very beginning of the clause according to the communicative purposes. 
    But this is not suitable to (3)-(9) and (11). In yes/no question as (3), “Do” must be placed at the very beginning of the clause to show the speaker’s expectation for the answer yes or no. In (4)-(5), the wh-word or group has to be put at the initial to expect the answer of one experiential element in the clause. In (7), wh-group assumes the subject of the clause. In the exclamatory clause (7), the exclamatory part is the emphasized element and must be placed at the beginning, and (8) the imperative clause, the verb is put at the initial to enhance the imperative tone.
    In (10), “interestingly” can be put after “the duke”, but it is put before and included in the Theme, which we could say it is the result of the choosing process by the communicator. In (9) and (11), whether the communicator choose or not, “but” must be put in the thematic structure to show cohesion with the pre-context. We can say that “but” is not the result of the choosing process. 
    Guowen Huang (2003:9) points out that in some clauses, although some elements are put at the beginning, it is not the result of communicator’s choosing process. He puts forward four “no choice” cases: Simple new content seeker, Binder, Linker and Operator.
    In (5), “What” assumes the Theme. In wh-questions, wh-element is put at the beginning of the clause and communicator has no choice about this and wh-element is known as Simple New Content Seeker. There are two relations in clause complex: hypotaxis and parataxis. (13) is a clause-complex in which “when I went into the room” is subject to “he was doing homework”. In clause “when I went into the room”, “when” is Textual Theme while “I” Topical Theme, the remaining is Rheme. In this case, “when” is Binder in the multiple Theme “when I”. (12) is also a clause complex with two clauses parallel with each other. In clause “and Mary likes vollyball”, “and” is Textual Theme and Mary Topical Theme in the Multiple Theme “and Mary”. “And” here is Linker. In yes/no questions such as (3), “Do you” assume the Theme with “do” as Interpersonal Theme and “you” Topical Theme. “Do” here is known as Operator.  In clauses above, the Theme such as “what”, “when”, “and” and “does” cannot be decided by the communicator based on purpose. It is a must choice.
III Arguments and Conclusions
A.  Regarding the Unmarked Theme
    According to Halliday, the Theme should be assumed by one and only one experiential element in the clause, which is criticized by other scholars for SFL School and other schools for its formalization and simplification. Berry summarizes ten hypotheses for the boundary of the Theme. She holds the view that the elements before the predicative verb all belong to the Theme. So in (2), the elements before the predicative verb “played” belong to the thematic structure, thus “yesterday” and “my son” are both the Theme. Downing (1991) argues against Halliday’s hypothesis that, which is supported by Fawcett (2008). Matthiessen (1992) thinks that the boundary of the Theme should be broadened. 
    Though the arguments mentioned above, many textbooks and papers still use Halliday’s definition for Theme. Matthiessen (1992) agree with Berry (1989) that the boundary of Theme structure should be up to include all the elements before predicative verbs, but when he was revising the third version of An Introduction to Functional Grammar (Halliday & Matthiessen, 2004:79), he still used the original description “The guiding principle of thematic structure is this: the Theme contains one, and only one, of these experiential elements. This means that the Theme of a clause ends with the first constituent that is either participant, circumstance or process.” 
    From the discussion in II-B and II-C, we could conclude that little debate arouse on the Unmarked Theme, which is usually assumed by the subject of the clause; the controversies mainly focus on the boundary in Marked Theme. The fourth edition of Halliday’s Introduction to Functional Grammar was published in 2014, there is a statement like this: “The message thus unfolds from thematic prominence – the part that the speaker has chosen to highlight as the starting point for the addressee – to thematic non-prominence”. 
    From this we could see that Halliday is also improving and revising the Theme theory. It is just through arguments that linguistic theories develop. 
B.  Regarding the Multiple Theme
    Regarding Simple Theme, Multiple Theme and Clause Theme, more debates focus on Multiple Theme. Fawcett (2008:181) thinks that Multiple Theme usually contains more than one clause element, sometimes one interpersonal Theme and one experiential theme, sometimes one textual Theme with one experiential theme, sometimes interpersonal Theme, textual Theme and experiential Theme, so the plural form multiple Themes maybe more acceptable than a multiple Theme. Fawcett (2008:181) also thinks that in clause like “In the morning Ike usually eats an apple for breakfast”, “in the morning ” assuming the circumstantial meaning and the Actor “Ike” should both be included in the thematic structure because they represent different thematic meanings. 
    According to Halliday, the speaker chooses an element as the Theme to reach his/her communicative purposes and Theme is the result of choices. However, in reality, the speaker could not choose in some situations and sometimes a certain choice precedes another one or one choice will limits the other choices, which means that Theme is not totally the result of choosing. The simple Theme in (8) is not the result of choosing by the speaker. “What” must be used here to assume the subject and the Theme. In clause complex (10), “and Sunny” is the Theme of the second clause, and is used to connect the two clause and the speaker has no choice here. In (11), if the speaker expects a “yes/no” answer, then wh-question will be excluded. 
    Halliday’s naming of Multiple Theme needs to be discussed to use the single form or plural form, and there are exceptions for Theme as a process of choosing. All these need further researches. 
C.  Conclusion
    Theme plays an important organizational role in the creation of texts. It is a crucial concept in the Textual Metafunction in Systemic Functional Linguistics, and Halliday’s definition and illustration of Theme has been influential for the past 60 years or so. However, since the late 1980s there have been a number of scholars who have been challenging Halliday’s original conception and illustration of Theme. Banks (2017) states that “Language is produced in and by a social situation, and cannot be fully understood without reference to that situation.” The investigation of thematic structure is also closely related with context. The boundary of Theme is flexible and influenced by context. It is not necessary to reach an agreement. 
    As a mature theory framework, SFL is developing in depth and width, but also improving its theory. The issue of notion of Theme and Theme boundary need to be further clarified. Although faced with challenges, Halliday’s theme theory still dominates the textbooks and majority of literatures. The Theme containing one, and only one, of these experiential elements and as the starting point of the clause makes it easier to identify Theme in discourse analysis. As a theory in textual function of SFL, the Theme theory plays an important part for readers to understand texts and writers or speakers to produce intended texts. The openness of metaphor feature of the theory ensures its vitality. 
    Meanwhile, context is brought into SFL. In 1992, Halliday regards context as continuum with cultural context on the left, situational context on the right and situation type in the middle in Language as system and language as instance: The corpus as a theoretical construct. How to apply SFL theories into text structure also becomes a research focus. Entering the 21st century, SFL are becoming more emerged with other fields and its theory frame is used in social semiotics, multimodal discourse, ecolinguistics, translation and computational linguistics etc. It is also used to address the practical problems in reality and is used in pedagogy to tackle teaching problems and promotes the development of communicative teaching approach, ideational teaching approach, situational teaching approach etc. SFL is both a theoretical linguistics and appliable linguistics (Halliday uses appliable rather than applied or applicable to describe the practical characteristics of SFL).

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