In this century is the first instance of the burning alive of a heretic, and it was Spain who lighted that first pile. Theodosius, of all the emperors of this age, was the bitterest persecutor of the heretic sects. "The orthodox emperor considered every heretic as a rebel against the supreme powers of heaven and of earth; and each of those powers might exercise their peculiar jurisdiction over the soul and body of the guilty.... In the space of fifteen years [A.D. 380-394], he promulgated at least fifteen severe edicts against the heretics; more especially against those who rejected the doctrine of the Trinity; and to deprive them of every hope of escape, he sternly enacted, that if any laws or rescripts should be alleged in their favour, the judges should consider them as the illegal productions either of fraud or forgery.... The heretical teachers ... were exposed to the heavy penalties of exile and confiscation, if they presumed to preach the doctrine, or to practise the rites of their _accursed_ sects.... Their religious meetings, whether public or secret, by day or by night, in cities or in the country, were equally proscribed by the edicts of Theodosius: and the building or ground, which had been used for that illegal purpose, was forfeited to the imperial domain. It was supposed, that the error of the heretics could proceed only from the obstinate temper of their minds; and that such a temper was a fit object of censure and punishment.... The sectaries were gradually disqualified for the possession of honourable or lucrative employments; and Theodosius was satisfied with his own justice, when he decreed, that as the Eunonians distinguished the nature of the Son from that of the Father, they should be incapable of making their wills, or of receiving any advantages from testamentary donations" (Gibbon's "Decline and Fall," vol. iii. pp. 412, 413).
One important event of this century must not be omitted, the dispersion of the great Alexandrine library, collected by the Ptolemies. In the siege of Alexandria by Julius Cæsar, the Philadelphian library in the museum, containing some 400,000 volumes, had been burned; but there still remained the "daughter library" in the Serapion, containing about 300,000 books. During the episcopate of Theophilus, predecessor of Cyril, a riot took place between the Christians and the Pagans, and the latter "held the Serapion as their head-quarters. Such were the disorder and bloodshed that the emperor had to interfere. He despatched a rescript to Alexandria, enjoining the bishop, Theophilus, to destroy the Serapion; and the great library, which had been collected by the Ptolemies, and had escaped the fire of Julius Cæsar, was by that fanatic dispersed" ("Conflict of Religion and Science," p. 54), A.D. 389. To Christian bigotry it is that we owe the loss of these rich treasures of antiquity.