Contrasts
There are a number of ways in which Blending Theory is distinct from Conceptual Metaphor theory. We begin by addressing these contrasts between the two theories.
Not all blends are metaphorical
First of all, it is important to emphasise that not all blends are metaphorical. As we saw earlier in our taxonomy of integration networks (section 12.5), the prototypical metaphorical network is the single-scope integration network. The hallmark of metaphor and of single-scope blends is frame-projection asymmetry: while both inputs contain distinct frames, it is only the frame from one of these inputs (the ‘source’ in conceptual metaphor terms, the ‘frame input’ in blending terms) that is projected to the blend. Although single-scope networks are the prototypical kind for structuring metaphor, we have seen that other kinds of network may also produce metaphorical blends as in the case of the double-scope example: You’re digging your own financial grave.
Blending does not involve unidirectional mappings
Unlike Conceptual Metaphor Theory, Blending Theory involves selective projection of structure from inputs to the blended space rather than unidirectional cross-domain mappings. In addition, structure from the blend can be projected back to the input spaces. Thus the two theories employ different architecture in order to model similar phenomena.
Spaces versus domains
Conceptual metaphors feature mappings (and domains) stored in long-term memory. These mappings hold between domains which are highly stable knowledge structures. In contrast, Conceptual Blending Theory makes use of mental spaces. As we saw in the previous chapter, mental spaces are dynamic and temporary conceptual ‘packets’ constructed ‘on-line’ during discourse. Despite this, blends can become conventionalised (for example, the GRIM REAPERblend), in which case the blend becomes established as a relatively stable knowledge structure in the conceptual system.
The many-space model
In their first Blending Theory paper, Fauconnier and Turner (1994) referred to conceptual integration or blending as the many-space model. This points to an obvious difference between Blending Theory and Conceptual Metaphor Theory: while Conceptual Metaphor Theory is a two-domain model, Blending Theory employs a minimum of four spaces.
Dynamic versus conventional
One consequence of the foregoing comparisons is that while Blending Theory emphasises the dynamic and mutable aspects of blending and its role in meaning construction, Conceptual Metaphor Theory emphasises the idea that there is a ‘metaphor system’ in which conceptual metaphors interact in order to provide relatively stable structure and organisation to the human conceptual system. This reflects the different emphases of the two traditions: metaphor theorists have been concerned with mapping the conventional patterns entrenched in conceptual structure, while blending theorists have been more concerned with investigating the contribution of conceptual integration to ongoing meaning construction. As we have seen, this does not entail that blending cannot give rise to conventionalised representations.
Difference in methodological emphasis
As a consequence of the previous contrast, while conceptual metaphor theorists have sought generalisations across a broad range of metaphoric expressions, conceptual blending theorists, while developing general principles based on specific examples, typically focus on the nature and particulars of those specific examples. This is because Blending Theory places emphasis upon a process of meaning construction rather than a system of knowledge.
Emergent structure
A particularly important difference between the two theories is that, while Blending Theory provides an account of emergent structure, Conceptual Metaphor Theory does not. This follows from the fact that Conceptual Metaphor Theory relies upon a two-domain model. We discuss this issue in more detail below.
