Johnson, Aaron, and Jeremy Schott, eds. 2013. Eusebius of Caesarea: Tradition and Innovations. Hellenic Studies Series 60. Washington, DC: Center for Hellenic Studies. http://nrs.harvard.edu/urn-3:hul.ebook:CHS_JohnsonA_SchottJ_eds.Eusebius_of_Caesarea.2013.
16. Eusebius and Lactantius: Rhetoric, Philosophy, and Christian Theology 
The list begins with Nero and continues through Galerius and the eventual triumph of Constantine (and Licinius), increasing in detail with each successive emperor. Given Lactantius’ expressed plan to show how the punishment of God was meted out, some consideration of the anger that led to punishment seems warranted. Yet there is no exploration of divine wrath, and only one mention of it, wherein Aurelian is described as having “provoked the anger of God.”  The emphasis instead is on God as punisher (vindex) and on his judgment, and not on the necessity of anger to these roles.
This programmatic statement comes immediately before Lactantius gives his readers a recapitulation of the book’s material. The philosophers’ refusal to attribute anger to God is presented as a significant factor in their greater misconception of the divine. It is also shaped as a topic worth its own separate treatment. Lactantius’ awareness of his projects in both texts and of their relationship to one another is further evidenced in the second chapter of De ira Dei, where he refers to this passage and its broader context as ample proof of philosophical error. 
A parable that appears in both the Gospel of Matthew (24:45–51) and that of Luke (12:24–48, but especially 35–48) lies at the core of this idea.  In each version of the parable, Jesus tells the story of a master who has unexpectedly come home. If this master discovers that his slaves have behaved well and are alert upon his arrival, he rewards them; if however he finds that the slave believed him to have been delayed, has beaten other slaves and has otherwise abused the master’s property, the master will “cut him into pieces.” 
The idea that humankind was formed in God’s own image has clear scriptural parallels, but the more important resonance here is that God placed (proposuit) both good and evil before humans. According to Lactantius, it is because God endowed humans alone with wisdom (sapientia), itself the one trait that most links humans to their creator, that they are capable of distinguishing between good and evil; the entire reason (ratio) for which that wisdom exists is to recognize what is good and what is evil and to respond appropriately. 
The direct scriptural references are those concerned with God’s creation of both good and evil. The connection between the creation of good and evil—and humankind’s ability to choose one or the other—would have been apparent to Lactantius as he sought to explain the existence of evil. This use of scripture presents us with a second example in which a biblical source is brought in to refute a Stoic claim.  It also gives us some insight to Lactantius’ exegetical practice. Much as in his consideration of divine anger, Lactantius chooses not to engage in an allegorical or figural interpretation of an idea or concept that traditionally has been given a negative association. While the Stoics, Lactantius argues, interpret an apparent evil as an actual good, what they should do is admit that it is actually an evil and that, because it came from God, exists for a specific purpose.  Here Lactantius subtly deploys a scriptural model as a challenge to the philosophical argument of his opponents. The way in which he does so is illustrative of his methodology: since he knows that these opponents would not accept proof that is explicitly scriptural (such as would be announced by a direct quotation), he incorporates just enough of the Deuteronomic verse to allow for its recognition by those familiar with it, but not so much as to cast suspicion on his claims. 
Lactantius begins with a classical analogy and quickly shifts to a biblical idea: Cicero would agree that the world is the house of God (mundus . . . dei domus), but perhaps not that humans are the slaves of God (homines . . . servi).  In this instance, Lactantius’ combination of the classical and biblical themes serves as a rebuttal of the Stoic claim for the unsuitability of anger, the attack of which he turns to in the next line.  Lactantius’ complaint here is that the Stoics cannot see the difference between right and wrong or between just and unjust anger. The criticism itself is made on moral grounds, but at the same time it echoes his critique of the Stoics in chapter five. There the problem was that the Stoics interpret bad things as good things in disguise; here it is that they cannot discern any difference whatsoever. The scriptural model of humans as the slaves of their master (God) provides Lactantius with the basis for his argument and a framework for understanding the relationship between mortals and the divine. It also allows him to articulate why anger is fitting for God. With an appropriate object, and when it is employed for the sake of justice, anger has a fitting place, unlike the mere desire for revenge on account of which the Stoics (argues Lactantius) view anger as a negative attribute. 
That matters of a philosophical nature could and should fall under the jurisdiction of the orator is thus an idea with which Lactantius would have been familiar; we see application of this principle in De ira Dei. It is not merely that Lactantius chose a medium of argumentation with which he was most comfortable, but rather that he saw in that medium a justifiable and appropriate way to express a matter of Christian theology.