When one studies 2,000 years of church history, there will certainly be a lot of heretics and heresies. Many Fathers and Doctors of the Church have written collections of polemics against the multiple heretical groups of the day. For example, we have Irenaeus of Lyons, Epiphanius of Salamis, and John of Damascus just to name a few. They’ve all written collections of polemics against certain heresies. Other saints have written extensively against one or a couple different heresies. Saint Augustine is a good example with his works against the Donatists and the Pelagians.