For the non-linguist, the rheme is one of the most difficult concepts in semiotics. It is not in architecture’s lexicon, and it’s hard to think of its relevance outside of language study. In fact, in material culture (e.g. architecture) we are more comfortable with the structure of metaphor than with the theme-rheme structure, as I will show.
Starting with grammar — most sentences in English come in two uneven halves, the subject and the predicate. The subject is what the sentence is about while the predicate is what is being said about the subject. Consider “The dog chased the rabbit.” “The dog” is the subject; “chased the rabbit” is the predicate.
In literature, as opposed to grammar, it is more interesting and meaningful to construct and analyse a sentence in terms of its theme and its rheme. The theme of a sentence is the part that you already understand by virtue of sentences that have gone before or as the subject of the sentence. A rheme is something supplemental to that, some additional information, or perhaps a comment (a predicate).
“I wandered” is a theme; “lonely as a cloud that floats on high o’er vales and hills” is a rheme (in the first line of the famous poem by William Wordsworth). In many cases, the rheme is experiential, qualitative and evocative. Without it, the poem would be flat, and not really a poem.
Instead of the theme-rheme structure those of us working with physical objects are probably more comfortable with concept of metaphor and its target-source structure.
Consider Le Corbusier’s famous metaphorical statement,”a house is a machine for living.” Simplify this to “a house is a machine” to make the metaphorical structure more obvious. The structure of the metaphor identifies the house as the target, while machine is the source. The source (machine) is called upon to explain the concept of the house, i.e. to explain the target.
In some contexts the target is complicated or unfamiliar. The source is the familiar concept recruited to explain the unfamiliar, e.g. “her past is an open book.” But metaphor theorists do not insist that is always the case. There’s an independence and reciprocity between the two halves of a metaphor.
A rheme needs its theme
The theme-rheme structure is interesting as C.S. Peirce isolates the rheme as something that can exist without its theme, while still retaining its provisional status.
If you don’t know the theme of the sentence (“I wandered”), then it is unlikely that the rheme (supplementary comment) will make sense. The rheme needs the theme.
Metaphors don’t need to be sentences, and are often buried inside them, or implied, e.g. Wordsworth’s walking as floating cloud metaphor. If you take away the target of the metaphor (walking) then you are still left with the source (floating cloud) which makes sense on its own. So that is one difference between the theme-rheme structure and the target-source structure of metaphor.
A singular rheme is like an unattached predicate, or “chemical atom or radicle with unsaturated bonds” according to a page of Peirce quotes about the rheme (or rhema).
Peirce and his commentators provide examples of rhemes such as ‘__ is red’, ‘__ is a blue-eyed cat’, ‘__ is happy’, where the underscore indicates the as-yet unspecified theme of the sentence. The structure of the rheme implies that something is expected: what is red, which cat is blue-eyed, who is happy or lonely as a cloud?
The rheme appears as one of several obsessions in Peirce’s writing, its incompleteness and sense of possibility providing the attraction for him. For Peirce
“A Rheme is a Sign which, for its Interpretant, is a Sign of qualitative Possibility, that is, is understood as representing such and such a kind of possible Object” (292).
Is there a rhematic architecture? As a rheme is part of what it is to be a sign, and the extent to which architecture trades in signs, then architecture is rhematic. But architecture is also expectant, full of spatial, theoretical, figurative and metaphorical gaps, erasures and possibilities.
As if a singular rheme in semiotics is not enough, there are several kinds depending on the number of gaps according to Peirce.
“If parts of a proposition be erased so as to leave blanks in their places, and if these blanks are of such a nature that if each of them be filled by a proper name the result will be a proposition, then the blank form of proposition which was first produced by the erasures is termed a rheme. According as the number of blanks in a rheme is 0, 1, 2, 3, etc., it may be termed a med[en] (from μηδέν, nothing), monad, dyad, triad, etc., rheme.” (299)
The metaphor of architecture as erasure (sous rature) has not escaped theorists of material culture.
- Bergman, Mats, Sami Paavola, and João Queiroz. 2018. Rhema. Commens: Digital Companion to C.S. Peirce. Available online: http://www.commens.org/dictionary/term/rhema (accessed 29 June 2018).
- Peirce, Charles Sanders. 1998. Nomenclature and divisions of triadic relations, as far as they are determined. In Nathan Houser (ed.), The Essential Peirce, Selected Philosophical Writings Volume 2 (1893-1913): 289-299. Bloomington, IN: Indiana University Press.
- Also see reflections on the rheme by Awbrey, Jon. 2008. Logic of relatives. Inquiry into Inquiry, 31 July. Available online: https://inquiryintoinquiry.com/2008/07/31/logic-of-relatives/ (accessed 30 June 2018).