The Hydra of Heresy
The church fathers often fill their prose with colorful images to describe the Christian faith and its opponents. One such example occurs in John Cassian’s treatise On the Incarnation which he composed at the behest of Leo, deacon of the Roman church (the future Pope Leo the Great), in response to the Christological errors of Nestorius in the east. In the opening of the treatise, Cassian called to his aid classical mythology, specifically the tale of the hydra. The slaying of the hydra was one of the twelve labors given to Hercules. The serpentine beast is described as having multiple heads, and its secret weapon was that every head that was cut off immediately sprang back as two fresh heads. You can imagine what a frustrating time it must have been to chop away at the monster! Eventually Hercules realized (with the help of his nephew) that he could apply fire to each of the stumps as he cut them off in order to prevent them from growing back. This he did and so successfully cut down his freakish opponent. Cassian was not the only early Christian author to turn to the tale of the hydra for describing heresies. Theophilus of Alexandria described Origen as the heretical hydra in one of his festal letters (preserved in Latin by Jerome), and Epiphanius also used the image for heresy in his famous Panarion, or medicine chest against the heresies. These authors were probably drawn to the image of the hydra due to the biblical description of Satan as a serpent. The description allowed them to show the relatedness of all heresies, and that at the root of them all lay the father of lies himself. Moreover, in Cassian’s account, the sword of the Spirit which is the Word of God takes the place of Hercules’ sword as the weapon to strike down the heresies. Here is the passage from Cassian’s work in which he describes the hydra of heresy.
The tales of poets tell us that of old the hydra when its heads were cut off gained by its injuries, and sprang up more abundantly: so that owing to a miracle of a strange and unheard-of kind, its loss proved a kind of gain to the monster which was thus increased by death, while that extraordinary fecundity doubled everything which the knife of the executioner cut off, until the man who was eagerly seeking its destruction, toiling and sweating, and finding his efforts so often baffled by useless labours, added to the courage of battle the arts of craft, and by the application of fire, as they tell us, cut off with a fiery sword the manifold offspring of that monstrous body; and so when the inward parts were thus burnt, by cauterizing the rebellious throbbings of that ghastly fecundity, at length those prodigious births were brought to an end. Thus also heresies in the churches bear some likeness to that hydra which the poets’ imagination invented; for they too hiss against us with deadly tongues; and they too cast forth their deadly poison, and spring up again when their heads are cut off. But because the medicine should not be wanting when the disease revives, and because the remedy should be the more speedy as the sickness is the more dangerous, ourLord God is able to bring to pass that that may be a truth in the church’s warfare, which Gentile fictions imagined of the death of the hydra, and that the fiery sword of the Holy Spirit may cauterize the inward parts of that most dangerous birth, in the new heresy to be put down, so that at last its monstrous fecundity may cease to answer to its dying throbs.
– Translation by C. S. Gibson in Nicene and Post-Nicene Fathers, second series, vol. 11; book 1, chapter 1. Read more here.