Whether joy is a virtue?

Objections

Objection 1 : It would seem that joy is a virtue. For vice is contrary to virtue. Now sorrow is set down as a vice, as in the case of sloth and envy. Therefore joy also should be accounted a virtue.
Objection 2 : Further, as love and hope are passions, the object of which is "good," so also is joy. Now love and hope are reckoned to be virtues. Therefore joy also should be reckoned a virtue.
Objection 3 : Further, the precepts of the Law are about acts of virtue. But we are commanded to rejoice in the Lord, according to Phil. 4:4: "Rejoice in the Lord always." Therefore joy is a virtue.