St. Francis de Sales highly valued purity of heart. His disciple Bishop Jean Pierre Camus wrote, “I can never express to you, or convey a right idea, of the high esteem in which he held purity of heart. He said that chastity of body was common enough even among unbelievers and among persons addicted to other vices; but that very few people could truly say, my heart is pure. I do not say that by this purity of heart he meant never being troubled by sinful desires, for that would be making the virtue of chastity to consist in insensibility; and what do those who are not tempted know about the matter? No; he placed it in never yielding to unlawful affections.”
The saint defined chastity of the heart as a complete renunciation of all illicit affections. Bishop Camus added: “And there is another chastity of the heart which consists in purity of intention, and this is also extremely rare, for as the Bishop [Francis de Sales] often said, it implies seeing nothing save God in all things, and all things in God. Where God is all in all, there we shall surely find a ray of paradise.”
Both humility and chastity are virtues that should be practised quietly. St. Francis de Sales said, “The virtues of humility and chastity always seem to me like those subtle essences which evaporate if they are not kept very tightly corked.” The saint considered it wise very seldom to speak of these two virtues, and it is wise to practise them unceasingly.
A powerful safeguard of chastity is “devotion to duties.” St. Benedict in his rule wrote, “Idleness is the enemy of the soul.” St. John Bosco said, “Avoid idleness and idle people; carry out your duties. Whenever you are idle you are in serious danger of falling into sin, because idleness teaches us all kinds of vice.”
St. Jerome gave this advice: “Love the knowledge of Scripture, and you will no longer love the sins of the flesh … Always have some work on hand, that the devil may find you busy.”
Love for study and work fills our mind with wholesome thoughts, whereas day-dreaming, idle chatting, and curious use of the media fill our mind with vain fancies, illusions, and dangerous thoughts. The website purityispossible.com contains excellent resources helping young people to be free from sexual addiction through discipline and work ethic.
Chastity is protected by modesty. St. Francis de Sales said, “However pure, transparent, and polished the surface of a mirror may be, the faintest breath is sufficient to make it so dull and misty that it is unable to reflect any image. So it is with the reputation of the virtuous. However high and well established it may be, according to the words of wisdom: Oh! how beautiful is the chaste generation! A thoughtless, unrestrained glance or gesture is quite sufficient to give occasion to a slanderous tongue to infect that reputation with the serpent’s venom, and to hide its lustre from the eyes of the world, as clouds hide the brightness of the sun.”
Our heart is made for love, and we have the natural desire for love. In order to foster the virtue of chastity, we should not only dispel evil thoughts and desires; we should also open our hearts to be filled with the love of God. Father Adolphe Tanquerey wrote, “Love for God shields the heart from sentimental affections, and thus spares us many a temptation.”
St. John Bosco urged young people to achieve chastity through the help of frequent reception of Holy Communion, frequent confession, and devotion to Our Lady. St. Josemaria Escriva said, “The miracle of purity has prayer and mortification as its two points of support.”
聖方濟，沙雷氏十分重視内心的纯潔。他的門徒，加繆主教舄道：『我從來不能向你們表達或送上一個合適的思想，有關他内心純潔的評價。他說肉身的貞潔，甚至在没有信仰的人中，或那些墮入其他邪惡的人中都是平常的；但很少數的人可以真的說，我内心是純潔的。我不是説他認為這純潔的心在於永不會為罪惡的意圖而煩惱，若是這樣潔德便在於没有感覺了；那些從没有被誘惑的在這面又怎能理解？不；他將内心純潔置於絕不會順從不法的情愛。』
這位聖人把内心的純潔定義為對所有不正當的情愛的完全拒絕。加繆主教補充說：『還有另一個内心的純潔，它包括純潔的意向，這也是極端罕有的，因為一如這主教 [聖方濟、沙雷氏]常說的，它意味著在萬事中只看見天主，並在天主內看一切。那裡天主是萬有中的萬有，我們在那裡一定可以找到天堂的曙光。』
謙遜和貞潔兩者都是應該靜靜地實踐的德行。聖方濟、沙雷氏說：『謙遜和貞潔對我來說，時常看似微妙的香精，如果瓶蓋沒有好好封妥便會揮發。』這聖人認為最好不要多談這兩德行，卻要不停地實行這兩德行。
貞潔的一個強力的保衛是『忠於職責』。聖本篤在他的規律中寫道：『空閒是靈魂的敵人。』聖鮑斯高說：『躲避空閒和空閒的人；做好你的責任。無論何時當你空閒的時候，你是處於嚴峻墮入罪惡的環境中，因為空閒教我們全部種種的邪惡。』聖熱羅尼莫有這樣的勸戒：『喜愛聖經的知識，你再不會喜愛肉慾的罪惡了…時常有工作在手中，好使魔鬼找到你正在忙碌。』
喜愛閱讀和工作，把我們的腦海充滿有益的思想；但是白日夢，閒談和跟隨媒體會以無用的幻想，幻覺和危險的思想填充我們的腦海。網站 purityispossible.com包含很好的資源以紀律和道德工作幫助年青人免陷於色慾的癖癮。
端莊保護貞潔。聖方濟、沙雷氏說：『但是純潔，儘管可以使一面鏡子如何通透，明亮，可是最微弱的一口吹氣亦可使它暗淡、蓋霧再不能反映影象。所以它是名譽的德行。無論它的建立是如何的好和高，據智慧篇之言：噢！貞潔的時代是何等的美麗！一個不經意的，不受約束的一瞥或舉措也不時足以讓誹謗的口舌以蛇蠍的毒液去影響他的名譽，並遮蓋它的光輝，一如密雲遮掩太陽一般。』
我們的心是由愛造的，我們本性上就有愛的希冀。要能撫育貞潔的德行，我們不應只是掃除邪惡的思想和願望；我們也要打開我們的心讓它滿充天主的愛。阿道夫·坦奎利神父寫道：『愛天主屏蔽我們的心免陷情感的依戀，由此免去我們很多誘惑。』
聖若望、鮑斯高催促青年們通過常妥善領聖體，勤善辦告解聖事和恭敬聖母去幫助他們保持貞潔。聖若瑟瑪利亞、施禮華說：『祈禱和克己是貞潔奇跡的兩個支持點。』
