Metaphor is Stepping Stool
I think that we might say that ‘X is A’ is a useful means for comprehending ‘linguistic metaphor’ and also comprehending a new and revolutionary cognitive theory, ‘conceptual metaphor’.
Linguistically I might say ‘X is A’ by which I mean X, the unknown, is like ‘A’ the known. The phrase ‘understand is grasp’ allows me to help someone comprehend the concept ‘understand’ by comparing it to the concept ‘grasp’. ‘It just flew over my head, I was unable to grasp it’ is an expression we all readily comprehend and it also is an example of using a metaphor to express our meaning.
But now comes the revolutionary ‘conceptual metaphor’, which I suspect will become a paradigm of cognitive science. ‘Conceptual metaphor’ is ‘cognitive DNA’. The idea ‘conceptual metaphor’ can be comprehended somewhat by considering it to be DNA like.
An infant might have the experience of warmth when first held by her mother. A concept, which is the neurological structure of this experience, is composed into a ‘mental space’. The experience, now becoming a concept, is structured by the brain so that the brain can draw appropriate inferences about this experience.
Let me call this concept, this experience, this neurological network, ‘B’. Cognitive science, with the aid of technology, has evidence to support the hypothesis that there are many circumstances wherein the brain automatically and without our consciousness of the happening, will ‘map’ parts of ‘B’ onto a new mental space and that structure will become part of the ‘DNA like structure’ of a new experience.
The experience of warmth by the infant can become part of the ‘cognitive DNA’ of the new and subjective concept ‘affection’. This is why we can easily comprehend that ‘affection is warmth’.
Cognitive science, which consists of scientist from the fields of neurology, philosophy, linguistics, and probably others, has been utilizing new technology to develop this possible new paradigm for cognitive science over the last three decades. The book “Philosophy in The Flesh†by Lakoff and Johnson is my source for this knowledge.
If your curiosity is aroused you might do a Google of “conceptual metaphor†(use the quotes).