How to use "virtue" in a sentence

While the people retain their virtue and vigilance, no administration, by any extreme of wickedness or folly, can very seriously injure the government in the short space of four years.

My public opinions are the same as those I express privately, and that's a virtue he doesn't possess

"Bravery is a virtue of fools."

He knew that none of the village women spoke to me because 6 they thought I had lost my virtue