"To err and not change one's ways" comes from The Analects, Book XV, "Wei Ling Gong." The original text reads, "To err and not change one's ways, this is what it means to err indeed." It means that making a mistake but failing to correct it is the real mistake. The deeper meaning of this idiom emphasizes that no one is a sage or worthy, so who can be free from error? The key lies in one's attitude toward mistakes. If one knows one is wrong yet stubbornly refuses to change, that is compounding one error with another and may even lead to a grave blunder. It is mostly used in criticism, admonition, or self-reflection, such as teaching others to have the courage to admit and correct mistakes, or describing someone who is obstinate and glosses over faults. In cultural background, Confucianism values self-cultivation and self-examination and stresses that "when you have faults, do not fear to abandon them." This idiom is a concise expression of that idea. Its emotional coloring is generally derogatory, carrying a sense of reproach, regret, or warning, and it is usually used in formal or serious contexts.
📝 Example
1. He clearly knew there were flaws in his plan, yet he let the error go uncorrected, which ultimately led to the project's failure. (refers to knowing one's mistake but failing to correct it)
2. As a leader, if one lets subordinates' faults go uncorrected, it will only allow problems to pile up beyond remedy. (refers to failing to correct mistakes)