The struggle for chastity is perhaps the defining moral battle of our age. An entertainment culture saturated in eroticism, the ubiquity of pornography, the collapse of courtship into serial cohabitation, and a social environment that treats sexual desire as having no proper order — all of this has created a generation of Catholics who suffer intensely from what the tradition called concupiscence of the flesh. This is not a new struggle; it is the oldest one. Augustine confessed it at length. Francis de Sales wrote a practical chapter on it for a French noblewoman. Thomas Aquinas gave it a precise theological analysis. But the particular intensity of the modern version — the ease of access, the neurological conditioning, the cultural affirmation — is genuinely new.
The Church's teaching on chastity is not primarily a set of prohibitions. It is, at its root, a theology of the body — the conviction that human sexuality is so sacred, so charged with meaning, so ordered toward the total self-gift of persons within the covenant of marriage (and, in another mode, toward the total self-gift of persons to God in consecrated life), that any misuse of it is not merely a rule violation but a kind of lie told in the body. This is John Paul II's great insight in the Theology of the Body: that the sexual act has a language, and that language can be spoken truthfully or falsely. Lust is the false use of that language.
The resources gathered here work at several levels simultaneously, because the struggle for chastity is not solved at one level only. It requires a positive vision (Theology of the Body), a practical method (de Sales), an interior life (Thérèse, Imitation of Christ), sacramental armor (rosary, scapular, confession), and the habit of placing certain images before the eyes and removing others. This is not a programme to complete; it is an armory to draw from. Begin wherever you are.