What are the views of Lactantius (c. 240–320 A. D.) on participating in military service?

Lactantius lived through Constantine’s conversion to Christianity, so his writings before Constantine’s conversion differ from those after his conversion. In his early writings, Lactantius rejects the right of a Christian to defend himself, even against who cause him harm; else he would lose his status as a righteous man. He says, “Thus it will be neither lawful for a just man to engage in warfare, since his warfare is justice itself, nor to accuse anyone of a capital charge, because it makes no difference whether you put a man to death by word, or rather by the sword, since it is the act of putting to death itself which is prohibited. Therefore, with regard to this precept of God, there ought to be no exception at all; but that it is always unlawful to put to death a man, whom God willed to be a sacred animal.”⁹⁶³ After the rise of Constantine, Lactantius softened his opposition to killing in war and to the judicial death penalty.