Metaphor has fallen out of my work almost completely. I think there’s one in the whole of Dumuzi. Why is that? (Not a rhetorical question.) Something in metaphor feels violent to me — wrenching a thing out of being-as-it-is so it can be yoked to some other thing and lend to its glory.
A metaphor is, at the least, a lie, and to go along with it, we need to split our consciousness in two — the one who accepts the lie, and the one who knows it for a lie. (Compare to the split induced by accentual-syllabic meters — one ear attentive to concrete particular speech rhythms, one to an abstract metrical pattern.)
Donald Revell on mixing metaphors: “A good way to kill the damn things off.”
Metonymy seems gentler, letting its two terms hang out together equably.
Both enlarge consciousness — one by an abrupt rending, the other by a steady gentle pressure outward.
I wonder, is compost, what actually happens in the compost bin, the vegetal smushing, closer to metaphor or metonymy?
The Art of Compost 