Italian term, derived from the Latin virtus and frequently used in Renaissance discussions of human character. The term, like its Latin source, does not mean "virtue" in the conventional modern sense, though it does imply "goodness" in contrast to "vice." Above all, it denotes the qualities that made a man (the source-word of vir-tus is vir, the classical Latin word for a high-status man) admirable, such as intelligence, competence, and energy. Niccolô Machiavelli in particular employs it to describe the qualities needed in a success-ful ruler, but it was a common word, used by many authors and al-ways having a complimentary connotation. When used with refer-ence to things, it implies power or efficacy, such as the virtù of a medicine or a weapon.
Historical Dictionary of Renaissance. Charles G. Nauert. 2004.