Before we launch into a project on “metaphor of learning” or “metaphor of teaching” or “metaphor of education”, we need to as powerfully as possible define our terms, in particular establishing the contextual meaning of the word “metaphor”.
Metaphor: “My love is a red, red rose.” -- My love is a red, read rose. Red only for me. Read only by me.
Do we, as infants, start out inherently drawing metaphors, only not initially realizing they are metaphors. We learned the concept “bird”, and we see something flying and say “bird”. This is actually deeper than metaphor – the flying thing IS “bird”. At some point we make the jump to simile, “Oh, the flying thing is not 'bird', it is LIKE 'bird' because it moves like a bird.”
We also move on to further master groupings with “a” and “the”, with “a” referring to one of many, and “the” referring to some singular instance, perhaps a thing in a special category by itself.
This would seem to be one way of visualizing a person's knowledge base: mental buckets of “things”, qualified by “a” or “the”, and held together by a latticework of metaphors and similes.