Did Thomas Aquinas support execution of heretics?

Today is the feast of Saint Martin of Tours – he was opposed to the death penalty for heretics and actively sought to stop it. On the other hand, Saint Thomas Aquinas explicitly stated that formal heresiarchs should be killed by the state for the common good of society. read more

Summa Contra Gentiles: For those who have been appropriately appointed, there is no sin in administering punishment. For those who refuse to obey God's laws, it is correct for society to rebuke them with civil and criminal sanctions. read more

Excommunication remained the penalty for such Church leaders who taught heresy. Aquinas' view is steeped in the traditions of Roman Law. A review of the legal history prior to the time of Aquinas reveals the nature of recommending execution of heretics. The issue came to a head with the Manichean (Cathari) heresy. read more

For Thomas Aquinas, heresy was an issue of public safety, because heretics were leading people to eternal punishment. This is only said to let us understand why Aquinas took this position. It is not to say that executing heretics is right; it is plainly contrary to Christ's teaching. read more