Okay, I have a question I need help with from Socrates' Republic..?

After Thrasymachus joins the conversation, he claims that injustice is cled among the virtues and is for the wise and the good; whereas justice, by implication, is evilk and embraced by the stupid and vicious. Socrates embarks upon his trademark elenchus to refute the claims of Thrasymachus; explain Socrates' elenchus please: