Whether martyrdom is an act of virtue?

Objections

Objection 1 : It seems that martyrdom is not an act of virtue. For all acts of virtue are voluntary. But martyrdom is sometimes not voluntary, as in the case of the Innocents who were slain for Christ's sake, and of whom Hillary says (Super Matth. i) that "they attained the ripe age of eternity through the glory of martyrdom." Therefore martyrdom is not an act of virtue.
Objection 2 : Further, nothing unlawful is an act of virtue. Now it is unlawful to kill oneself, as stated above (Question [64], Article [5]), and yet martyrdom is achieved by so doing: for Augustine says (De Civ. Dei i) that "during persecution certain holy women, in order to escape from those who threatened their chastity, threw themselves into a river, and so ended their lives, and their martyrdom is honored in the Catholic Church with most solemn veneration." Therefore martyrdom is not an act of virtue.
Objection 3 : Further, it is praiseworthy to offer oneself to do an act of virtue. But it is not praiseworthy to court martyrdom, rather would it seem to be presumptuous and rash. Therefore martyrdom is not an act of virtue.