I've looked up each and every possible meanings of sound. I've reduced the options to two or so. But I still find it hard to ascertain the meaning of sound and the way its is used in this context.
Here it is:
We cannot, like fear-ridden peasants of antiquity, hope to load all our crimes onto a goat and then drive the hapless animal into the desert. Our everyday idiom is quite sound in regarding “scapegoating” with contempt.
Naturally, I can't come up with an intelligible meaning or paraphrasing of the relevant sentence.
The idiom we use everyday is highly reliable to despise "scapegoating".
The idiom we use everyday has very valid reasons for looking down on "scapegoating". (The idiom has reasons??? I don't know.)
The idiom we use everyday gives us very valid reasons to disdain "scapegoating".
Obviously, I'm confused and need help.