Tertullian, the great apologist of the Church in the second century, writes: “All other frenzies of lusts which exceed the laws of nature and are impious toward both bodies and the sexes we banish… from all shelter of the Church, for they are not sins so much as monstrosities.” (Tertullian, De pudicitia, IV)
 
Saint Basil of Caesarea, the fourth century Church Father who wrote the principal rule of the monks of the East, establishes this: “The cleric or monk who molests youths or boys or is caught kissing or committing some turpitude, let him be whipped in public, deprived of his crown [tonsure] and, after having his head shaved, let his face be covered with spittle; and [let him be] bound in iron chains, condemned to six months in prison, reduced to eating rye bread once a day in the evening three times per week. After these six months living in a separate cell under the custody of a wise elder with great spiritual experience, let him be subjected to prayers, vigils and manual work, always under the guard of two spiritual brothers, without being allowed to have any relationship… with young people.” (St. Basil of Caesarea, in St. Peter Damien, Liber Gomorrhianus, cols. 174f.)
 
Saint Augustine is categorical in the combat against sodomy and similar vices. The great Bishop of Hippo writes: “Sins against nature, therefore, like the sin of Sodom, are abominable and deserve punishment whenever and wherever they are committed." (Rom. 1:26). (St. Augustine, Confessions, Book III, chap. 8)
 
Saint John Chrysostom writes: “All passions are dishonorable, for the soul is even more prejudiced and degraded by sin than is the body by disease; but the worst of all passions is lust between men… There is nothing, absolutely nothing more mad or damaging than this perversity.” (St. John Chrysostom, In Epistulam ad Romanos IV)
 
Saint Peter Damian’s Liber Gomorrhianus [Book of Gomorrah], addressed to Pope Leo IX, is considered the principal work against homosexuality. It reads: “Just as Saint Basil establishes that those who incur sins [against nature] … should be subjected not only to a hard penance but a public one, and Pope Siricius prohibits penitents from entering clerical orders, one can clearly deduce that he who corrupts himself with a man through the ignominious squalor of a filthy union does not deserve to exercise ecclesiastical functions, since those who were formerly given to vices … become unfit to administer the Sacraments.” (St. Peter Damian, Liber Gomorrhianus, cols. 174f)
 
Saint Thomas Aquinas, writing about sins against nature, explains: “However, they are called passions of ignominy because they are not worthy of being named, according to that passage in Ephesians (5:12): ‘For the things that are done by them in secret, it is a shame even to speak of.’ For if the sins of the flesh are commonly censurable because they lead man to that which is bestial in him, much more so is the sin against nature, by which man debases himself lower than even his animal nature.” (St. Thomas Aquinas, Super Epistulas Sancti Pauli Ad Romanum I, 26, pp. 27f)
 
Saint Bernardine of Siena, a preacher of the fifteenth century, writes: “No sin has greater power over the soul than the one of cursed sodomy, which was always detested by all those who lived according to God….. Such passion for undue forms borders on madness. This vice disturbs the intellect, breaks an elevated and generous state of soul, drags great thoughts to petty ones, makes [men] pusillanimous and irascible, obstinate and hardened, servilely soft and incapable of anything.  Furthermore, the will, being agitated by the insatiable drive for pleasure, no longer follows reason, but furor.” (St. Bernardine of Siena, Predica XXXIX, in Le prediche volgari (Milan: Rizzoli, 1936), pp. 869ff.)