Confucianist Usages
The Four Books of Confucianism give some insightful explanations of de "virtue". Note that the following quotations cite Charles Muller's scholarly translations of the Analects, Doctrine of the Mean, Great Learning, and Mencius. The more familiar translations of James Legge render ren "humaneness; human-heartedness" as "perfect virtue", which occasionally creates confusion with de as "virtue". Compare their translations of these two Analects passages.
Yen Yüan asked about perfect virtue. The Master said, "To subdue one's self and return to propriety, is perfect virtue. If a man can for one day subdue himself and return to propriety, all under heaven will ascribe perfect virtue to him. Is the practice of perfect virtue from a man himself, or is it from others?" (12:1, tr. Legge)
Yen Yüan asked about the meaning of humaneness. The Master said, "To completely overcome selfishness and keep to propriety is humaneness. If for a full day you can overcome selfishness and keep to propriety, everyone in the world will return to humaneness. Does humaneness come from oneself, or from others?" (12:1, tr. Muller)
The Master said, "Let the will be set on the path of duty. Let every attainment in what is good be firmly grasped. Let perfect virtue be accorded with. Let relaxation and enjoyment be found in the polite arts." (7:6, tr. Legge)
Confucius said: "Set your aspirations on the Tao, hold to virtue, rely on your humaneness, and relax in the study of the arts." (7:6, tr. Muller)
Read more about this topic: De (Chinese)