Individual virtues, while requiring the work of other people, focus primarily on the person and their overall character. Civic virtues emphasize living and relating to one another in a community (Nicomachean Ethics, Book IV, lines 1125b-1128b). In fact, a city built on certain individual virtues could collapse in its foundations. This does not mean that all individual virtues would bring society to its knees, but if it also lacks all civic virtues, this can only lead to ruin. For example, you wouldn't want a city full of magnanimous men. For one thing, all they care about is receiving honor, but not giving it (Nicomachean Ethics, par. 1123b line 22). They give grandly and extravagantly to gain the admiration and good reputation of their peers. As an individual goal to strive for, that's fine. There is a need in the city for some men to give generously for the betterment of society. But if there were a city full of men, no one would be available to praise them and donations would cease to exist. A city full of brave men willing to risk their lives for the good of their city would be fine as long as all they care about is