When reading Locke's determination of idioms and metaphors I can see the difficulty trying to depict the difference, and the question of whether or not an idiom is a metaphor. Metaphors are defined as a figure of speech, or a symbolic representation of an object. Idioms are representations words or phrases, more relatable to an idea, not an object.
I can't help but think about the Outkast song "Roses." To unpack this song's lyrics, there are a couple lines that can be broken down and defined as either an idiom or a metaphor, in my opinion:
"She needs a golden calculator to divide" symbolizes that 'she' is a brat or high maintenance. I consider this an idiom.
"Roses really smell like poo" is metaphorically symbolizing that pretty things aren't always pretty on the inside. But technically roses could really smell like poo, but the context the artist uses this phrase is to describe another object.
Reading through the different posts, I acknowledged everyones opinion of how idioms relate to metaphors, and I think sometimes Locke's notes may confuse a few people. It was a little difficult to read and adjust the similarities and differences at the same time.
Locke says, “Complex ideas are not universal[.]” (815) Complex ideas include metaphors and idioms. The concept of these complex ideas are actually really great. These ideas, (metaphors and idioms) will change cultrally and throughout different communities. They are so flexible and diverse that it draws me to think about Locke's theory on the abuse of language. We have the ability to liguistically relate words to other words or phrases, and words to non relative objects. Its actually a pretty powerful thing when you think about it; I don't consider metaphors and idioms as an abuse of language because we are using our minds to creatively draw an abstraction about one thing or another. Hence the term, "complex."