ANSWER: By fulfilling "the three counsels of perfection," the vow of poverty, of obedience to the superior of the monastery or nunnery, and chastity. The priests promise only subordination to the hierarchy and celibacy — a far different thing from chastity. Neither the secular priests nor the laity can attain perfection, except by going through purgatory.
— Steele's Answers pp. 199, 200.