For this Lent's quote posts, I did something different and rather than just loosely unifying it by author or theme, I gave it some rough structure. Here is the index for the posts, along with brief precis of the contents.
THE SACRAMENTS IN GENERAL
I. Sacraments are sensible signs divinely instituted as remedies; they represent by likeness, signify by institution, and convey grace by sanctification. (Bonaventure)
II. In the sacraments the Holy Spirit works as it were in a secret way. (Isidore)
III. Sacraments in the proper sense are signs of holy things insofar as they make things holy. (Thomas Aquinas)
IV. A sacrament is a sign of Christ's Passion, of present grace, and of future glory. (Thomas Aquinas)
V. A sacrament is a stable sign signifying sanctity that has its effect simply from being done. (Alphonsus Liguori)
VI. Sacraments have divine institution as their efficient cause, sensible sign as their material cause, sanctification by grace as their formal cause, and medicinal healing of humanity as their final cause. (Bonaventure)
VII. The sacraments only have efficacy through Christ's humanity and His Passion. (Thomas Aquinas)
THE SEPTENARY
VIII. The Seven may be understood on analogy with physical life. (Thomas Aquinas, Robert Bellarmine)
IX. The Seven may be understood by considering human defects in need of remedy. (Bonaventure)
X. The Seven may be understood by considering aspects of sinful action that are in need of remedy. (Thomas Aquinas)
XI. The Seven may be understood by considering their connection to the seven Christian virtues. (Bonaventure, Thomas Aquinas)
XII. The Seven may be understood by considering what is needed for the spiritual fight. (Bonaventure)
XIII. The Seven may be understood in terms of essential acts of spiritual hierarchy. (Thomas Aquinas)
BAPTISM/ILLUMINATION
XIV. Baptism is the first and most necessary sacrament, by which we are adopted as children of God. (Peter Canisius)
XV. Baptism is a great thing, but to achieve it one must pass the serpent. (Cyril of Jerusalem)
XVI. By His Baptism, Christ makes our baptism His own. (John Damascene)
XVII. We baptize infants because no one may attain to heaven without baptism or desire for it. (Robert Bellarmine)
XVIII. In baptism and chrismation, the people of the Church support the assent of faith of those who receive with their own assent of faith. (Cyril of Alexandria)
XIX. Baptism shows that the power that restores us is the power of the whole Trinity. (Bonaventure)
CONFIRMATION/CHRISMATION
XX. Confirmation is a sacrament, given by the bishop, that strengthens us so that we may firmly believe and when necessary freely confess Christ. (Peter Canisius)
XXI. By chrismation we are made Christs, receiving the Holy Spirit as He did in His Baptism. (Cyril of Jerusalem)
XXII. Just as bread in the Eucharist becomes the Body of Christ, so oil in chrismation becomes the gift of Christ's grace, imparting the Holy Spirit. (Cyril of Jerusalem)
XXIII. By baptism we are sealed as part of the household of Christ; by confirmation we are sealed as soldiers in the army of Christ. (Robert Bellarmine)
EUCHARIST
XXIV. Through the Eucharist we partake of Christ's Body and Blood and thereby come to bear Christ in us, partaking in His divine nature. (Cyril of Jerusalem)
XXV. The bread and wine truly become the very Body and the Blood of Christ. (John Damascene)
XXVI. As baptism is the sacrament of faith, so the Eucharist is the sacrament of charity. (Thomas Aquinas)
XXVII. In communion, we say 'Amen' in order to affirm that the Eucharist is truly the Body and the Blood and therefore should believe what we say we believe. (Ambrose)
PENANCE/CONFESSION/RECONCILIATION
XXVIII. As we are united with God through baptism, after sinning we are re-united, reconciled, with God through penance, which is a kind of self-punishment. (Isidore)
XXIX. The three parts of penance are contrition, confession, and satisfaction. (Peter Canisius)
XXX. Penance manifests the justice of Christ as Judge, and anticipates the Final Judgment. (Bonaventure)
XXXI. The principal effect of a sacrament can be had without the sacrament or derivatively through another sacrament, but not without the relevant desire for that sacrament; thus, even though extreme unction remits sins, we should still seek confession as well. (Thomas Aquinas)
EXTREME UNCTION/ANOINTING OF THE SICK
XXXII. The effects of unction are to remit the remainders of sins, to refresh the sick, and, when expedient for the health of the soul, to heal the body. (Robert Bellarmine)
XXXIII. Unction is given that we might be adequately cleansed for heaven, regardless of anything that may prevent our complete purification. (Thomas Aquinas)
ORDER/ORDERS
XXXIV. Order is a sacrament given so that the dispensation of the sacraments may be done in a distinctive, effective, and orderly manner. (Bonaventure)
XXXV. The priestly ministry represents the ministry of angels, so that even while on earth we may contemplate heavenly things. (John Chrysostom)
XXXVI. While priests may be tainted and corrupt, the gift received through them, being from God, is always pure. (Peter Damian, Augustine)
MATRIMONY/CORONATION
XXXVII. In matrimony, those who marry hand themselves over to each other for fellowship, for raising children, and for curing concupiscence; its matter consists in the consent that gives and its form in the consent that receives. (Alphonsus Liguori)
XXXVIII. Matrimony imitates the Passion of Christ insofar as it imitates Christ's love for the Church. (Thomas Aquinas)