Sacerdotii Nostri Primordia §22

²² We want to use this letter, Venerable Brethren, to exhort, again and again, all of them, and especially those who are working alone and in the midst of very serious dangers of this kind, to let their whole life, so to say, resound with the splendor of holy chastity; St. Pius X had good reason to call this virtue the "choicest adornment of our order." (33)