This question came up recently in another forum. My takeaway from that discussion is as follows. The root of virtus is vir, a masculine noun meaning "man". The addition of the suffix -tu- denoting "quality" always creates a feminine noun, regardless of the root. For students of Latin, the ending of virtus is not "-us", first-declension masculine, but simply "-s", third-declension feminine. A personification shares the gender of the word personified. Therefore, Virtus is the "goddess" (for lack of a better word) of manliness. It is not always obvious that the figure beneath the armor is female. Sometimes the armor is light and the figure rounder, like the op coin of Trajan. When the figure is clearly male, it should be interpreted as the emperor (or Mars) displaying virtus, not as a depiction of Virtus herself.
Edited by Kushanshah
10/13/2020 10:06 am