The core of DMT as a theory is the proposal that there is an interaction between variation in the structures and functions of metaphor as language, on the one hand, and variation in the psycholinguistic processes and products of metaphor as cognitive process. Distinct structures and functions of metaphor in language can give rise to diverging processes of metaphor comprehension, some of which do not go via analogy or cross-domain mapping. This proposal allows for the paradox of metaphor, which says that most metaphor in language is not processed as metaphor in comprehension.

The explanation of this observation is that metaphor in language is represented in a four-dimensional way in comprehension. Different properties of metaphor in language for each of these four dimensions create different types of metaphor, which can have different effects on metaphor representation in the mind. What may linguistically be identified as involving a figurative analogy or cross-domain mapping is not necessarily processed by analogy in comprehension. It is especially the intention to use a metaphor as a metaphor (part of the communicative dimension of all utterances) that is decisive. This can be read off the intended referents of a metaphor in an utterance, which can belong to a source domain or the target domain, which however is often unclear in principle.

This is because the bulk of metaphor is based in figuratively motivated polysemy. This generates an ambiguity of metaphor in terms of its intended reference that is ubiquitous. The ambiguity of metaphor then allows for ambivalent metaphor use between metaphorical meaning versus non-metaphorical meaning for the same expression. This explains the paradox of metaphor.

But this ambivalent use is not only due to structural properties of metaphor. It is also affected by properties of the discourse event. If participants in the medical domain are aware of cancer metaphors they object to, then they can resist some non-deliberate metaphors and turn them into deliberate metaphors in their own comprehension. If readers of poetry assume that poetry is metaphorical by definition, then they may turn non-deliberate metaphors into deliberate ones during their reception process. DMT predicts that discourse aspects play a fundamental role in metaphor comprehension for specific configurations of metaphor in structure and metaphor in process.