and the church as a very intimate one. "Human affairs cannot," he says, "be safe unless the royal and sacerdotal authority combine to defend the faith" (Ep. Ix. 983). He tells the emperor Leo on his accession that his empire is given him "not only to rule the world, but to defend the church" (Ep. clvi. 1323). When he praises an emperor he ascribes to him a "sacerdotal" mind (e.g. Ep. clv. 1319). The civil power is constantly called upon, at any rate in the East, where Leo could not always depend on the ecclesiastical authorities, to do the work of the church (Epp. cxii. 1189, cxv. 1203, cxxxvi.), and he justifies the execution of Priscillian in the previous century on the ground "that though the lenity of the church, contented with a sacerdotal sentence, is averse from taking a bloody revenge, yet at times it finds assistance in the severe commands of Christian princes, because the fear of punishment for the body sometimes drives men to seek healing for the soul" (Ep. xv. 696).
As an ecclesiastical ruler we will consider Leo first in his relation to the various heresies in the West. Septimus, bp. of Altina, in the province of Aquileia, writes (Ep. i. Migne) to inform Leo that Pelagian ecclesiastics are being admitted to communion in that province without recantation, are being reinstated into their ecclesiastical degrees, and allowed, contrary to the canons, to wander from church to church. Leo writes to the metropolitan to complain, desiring him to summon a provincial synod and extract from suspected persons a condemnation of Pelagian errors (i. 591). Of his struggle with the Manicheans we know more. Recent troubles, especially the capture of Carthage by Genseric in 439, had driven many of these heretics to Rome. They were to be seen there moving about with pale faces, in mean apparel, fasting, and making distinctions of meats. They seem to have professed Catholicism and done their best to escape attention (Leo Mag. Serm. xvi. 4, xxxv.; Ep. xv. 16, p. 708). The vigilance of Leo, however, was too much for them. Of this sect he had a particular horror. Their heresy is a mixture, he says, of all others, while it alone has no element of good in it (Serm. xvi. 4, xxiv. 5). Accordingly, in the beginning of 444 Leo made a diligent search for them. A large number, both of teachers and disciples, and among them their bishop, were tried in the presence of numerous authorities, ecclesiastical and civil, a "senatus amplissimus," as Valentinian calls it, at which confession was made of the most hideous immoralities in their secret assemblies (Epp. vii. p. 624, xv. 16, p. 708; Serm. xvi. 4, and Constitutio Valent., Ep. viii.). Those who remained impenitent were banished in perpetuum by the civil power, and a constitution of Valentinian reviving the previous laws against the sect, dated June 19, 445, put them under all kinds of civil penalties. Leo, by sermons (ix. xvii. xxiv. xxxv. xlii.) and a circular letter to the bishops of Italy (Ep. vii.), did all he could to publish their infamy, and his exertions appear to have stirred up other bishops, both in the East and West, to similar activity (Prosper and Idatius, Chron., Patr. Lat. li. 600, 882).Theodoret, writing in 449, counts this exhibition of zeal against the Manicheans one of St. Leo's greatest titles to fame (Leo Mag. Ep. Iii. c. 2). In 447 we find Leo sending an account of these proceedings to Turribius, bp. of Astorga (Ep. xv. 16, 708. At this period the Priscillianists were exercising a very disastrous influence in Spain. St. Turribius, their active opponent, wrote to Leo for advice, and Leo replies in July 447 (Ep. xv.). He views the heresy as a mixture of Manicheism with other forms of evil, heretical and pagan, and exhorts Turribius to gather a synod of all the Spanish provinces to examine into the orthodoxy of the bishops; with this view he sends letters to the bishops of the various provinces, but urges that at least a provincial synod of Gallicia should be held (c. 17). We find subsequent allusions to a Gallician council, to which Leo is said to have written (Labbe, Conc. v. 837 A; Idat. Chron. xxiii.), and to a council of various provinces at Toledo in 447, which is said to have acted "cum praecepto papae Leonis" (Labbe, ii. 1227 B; cf. Tillem. xv. 555 seq.; Ceillier, x. 668). Though we hear still of Novatianism and Donatism in Africa (Ep. xii. 6), Leo did not take any special measures against these nor other heresies in the West.
Leo's introduction to Eastern disputes is a somewhat curious one. Eutyches early in 448 wrote to Leo apparently deploring the revival of Nestorianism. Leo replied on June 1, applauding his solicitude, and apparently heard no more of Eutyches till early in 449 he received two letters announcing his condemnation in the council of Constantinople—one from the emperor Theodosius, the other from himself. Eutyches (Ep. xxi.) appeals to the judgment of the Roman pontiff. Leo, however, maintains a cautious attitude; writes to Flavian (Ep. xxiii.) complaining that he has sent him no information about the condemnation of Eutyches, that the appeal of the condemned to Rome was, according to his own account, not received and he himself hastily condemned, though he professed himself ready to amend anything in his faith which should be found at fault. At the same time Leo writes to the emperor, lamenting his ignorance of the true state of the case (Ep. xxiv.). Meanwhile, it appears that Flavian had really written soon after the close of the council to inform Leo, and to Domnus of Antioch and other prelates. His letter, however (Ep. xxii.) had not reached Leo by the end of Feb. 449. Had it arrived, it would have been calculated to give Leo a clearer view of the dogmatic question at issue. Flavian's second letter to Leo, in reply to his (Ep. xxvi.), contains no allusions to Leo's complaints of his silence and want of consideration; he characterizes Eutyches's representations as crafty and false, explains clearly the drift of his teaching, and urges the pope to send his subscription to the condemnation, and to keep the emperor on the right side (ib. p. 788); the matter, he adds, only needs his assistance to keep it all straight. Leo, now confirmed in his adhesion to Flavian, writes briefly in May 449, assuring him of his sympathy (Ep., xxvii.), followed in June by "the tome" (Ep. xxviii.), one of the most justly celebrated of pontifical decrees nominally a letter to an individual bishop,
