“Metaphors make connections which are not contained in the fabric of reality but created, by our own associative powers. The important question about a metaphor is not what property it stands for, but what experience it suggests.” - Sir Roger Scruton, On Beauty
Another interesting article. I am reminded of two things from my past.
The first is reading some old 16th century philosophy. I believe it was Thomas Hobbes' Leviathan, which is itself a metaphor for big government. In any case, the book spoke about how humans understand the World. To your example, the text used the term "dogness" when describing how humans see dogs. We don't see the dog, we see its dogness, which I take to mean the qualities of a dog. And these qualities, as you point out, are references to other concepts. For example, some dogs, as well as cats, have ears that are triangular, which is a term that can be used to describe many unrelated things.
This leads me to my second experience, which I had about 20 years ago. I was tasked with writing a patent application for a group of researchers who were working on a computerized natural language ontology. It was quite an education in human language. Understanding the idea of a natural language ontology at all was quite a challenge. It basically involved linking words to concepts, then to each other via common linkages to concepts. As you say, everything is a metaphor. For them, it was literally true.
'Take the word “dog” for example. It is a referring to the schema of a living thing we can recognize and distinguish from “cat”. When a child learns the word, he learns it as an association for that cute four legged creature with floppy ears and fur that he saw in the park. He distinguishes it from “cat” at home which although four-legged and furry, has much more of an attitude and pointy ears on its head.'
In my observation, this takes time. A young child (say, two) raised with a cat will see a dog for the first time and say, "cat", similarly a child raised with a dog upon seeing a cat ("dog!"). Clearly, as de Saussure and others before him pointed out, words mark concepts, not things in the world. Concepts are then applied to things, and concepts (e.g., smallish four-legged animal with a tail) and words (e.g., "cat" vs. "dog") , may then be refined. Poetry strikes me as sometimes crafting words and phrases for concepts that we know but do not yet have words for. It is possible that it works the other way as well, finding words for concepts we haven't thought of yet.