Dignum deo means “that which is fitting of God” or “that which is dignified of God”. The term is used to label theology that bases its understanding of God on what God “should” be. This is usually synonymous with “Perfect Being” theology.
Plotinus assumed that God “should be” the “greatest good”. Plotinus built his theology around the implications of what the “greatest good” should mean (timelessness, immutability, omniscience, etc.). Modern Christians adopt the same dignum deo theology when they label God as “perfect” and then form their theology around what they determine to be “perfect”.
The problem is dignum deo and “perfect being” theology is that this metric is very arbitrary. What necessitates that God be the “best conceivable” being? If one takes the God of the philosopher (who the philosopher determines to be “perfect”) and then one small item is disallowed (maybe God is perfect except that He cannot make a “Big Mac”), then why is it that this being cannot be “God”? The philosopher will object because that would violate the definition of God (the same definition they arbitrarily created despite world history using a very different definition). The philosopher just uses word definitions to disallow opposition. Assumedly, he would be forced to label anyone who believes in “God who cannot make Big Macs” as an “atheist”.
Another huge problem is that value is subjective. Maybe one person thinks that immutability is perfection and reasons that God never changes in any detail. Alternatively, a modern American might value dynamitism and then reason that God is dynamic in all things always. The philosophers argue endlessly about what makes a being “perfect” with zero resolutions. Their assumption is that there is some sort of secretive and non-obvious standard of perfection. This claim is not obvious on face value. Different people can have difference “perfect” cars in mind. Both are right, because there is no such thing as a perfect car unless it is allowed multiple and rival states of perfection. This seems to be the case as well with Perfect Being theologians. The problem with dignum deo theology is that completely opposite conclusions can be reached because the theology is heavily based in subjectivity.
Of course, reality is not determined by subjectivity. One cannot just make up definitions to words or subjectively determine what would be a best possible state in order to change reality. No matter how much someone wants to believe a destroyed bridge will allow them to cross a river, they will get a strong dose of reality when they try to cross. Good intentions and arbitrary beliefs do not translate to fact.
Opposed to dignum deo theology is Biblical theology. God’s attributes are defined by the Bible. As long as the Bible is consistent about who God is, this is not a problematic theological approach. The problem comes in when individuals try to mix dignum deo with the Bible. Often passages must be allegorized and misinterpreted to fit people’s notion of what is fitting.
Rightly, Open Theists call out Calvinists who do so. This is a major argument for Open Theism. Also rightly, Calvinists call out Open Theists who hold a double standard. Bruce Ware states:
We read, “Then the LORD said, ‘Because the outcry against Sodom and Gomorrah is great and their sin is very grave, I will go down to see whether they have done altogether according to the outcry that has come to Me. And if not, I will know” (vv. 20-21, emphasis added). Open theists insist that language about God learning from what happens ought to be taken “literally” or in a “straightforward” manner. Well, consider what we would end up with from this passage if we follow this openness approach. First, we would have to deny that God is omnipresent (i.e. , everywhere present), because God says that he has to “go down to see” if what he has heard is true. This indicates, on a “straightforward” reading, that until God gets to Sodom, he cannot know whether the reports he has heard are correct. Second, we would have to deny that God knows everything about the past, for he has to confirm whether the Sodomites have done these horrible things. Evidently, then, God does not know whether what he has heard about their past actions is true, so he doesn’t know the past perfectly. Third, we would have to deny that God knows everything about the present. Because he has to go down to see, God doesn’t know right now whether the reports are true.
William Lane Craig also points out:
1. Openists have their own conception of what is dignum deo, and they don’t hesitate to draw on it when the Scriptures are silent. For example, if the openists are right that the Bible doesn’t clearly teach exhaustive omniscience with respect to the future, it’s no less true that it doesn’t clearly teach exhaustive omniscience with respect to the past and present; yet openists accept the latter. Why? Presumably because ignorance of any detail of the past and present would not be dignum deo.
We can see this failing of leading Open Theists at work. In the Openness of God, William Hasker writes on dignum deo (perfect being theology):
The difficulties with perfect being theology do not, in my view, stem from the assumption that God is an absolutely perfect being-that he is “whatever it is better to be than not to be.” Rather, difficulties have arisen because people have been too ready to assume that they can determine, easily and with little effort, what perfection is in the case of God-that is, what attributes a perfect being must possess. Yet it clearly is no simple matter to say what is the best kind of life for a human being or what are the ideal attributes (or virtues) for a human being to possess. So why should we assume that this is simple in the case of God? I do not think it should be taken as obvious, without long and thoughtful consideration, that it is “better” for God to be temporal or timeless, mutable or immutable, passible or impassible. So if we are going to object to Plato’s argument, we need not reject perfect being theology as such; rather, it is the application the argument makes of divine perfection that we must question.
A few pages later Hasker falls for the same error he criticizes. Hasker attributes “omniscience” to God and then defines it based on “fitting” terminology rather than proving it from the Bible:
Divine omniscience. Just as God is said to be all-powerful, he is also said to be all-knowing, or omniscient. Here also we need to go beyond the mere word to a careful definition. My proposal is: To say that God is omniscient means that at any time God knows all propositions such that God’s knowing them at that time is logically possible.
Hasker does this improper defining of several attributes, definitions of God’s attributes based on what Hasker believes is a good definition rather than a Biblical definition. A large portion of Open Theists are dignum deo Open Theists, believing that God is Open based on what would be fitting of a “loving God”. The same mindset is present in process theists. This mindset should be rejected as subjective and non-Biblical. Human beings cannot just invent things in their own mind and expect reality to conform. If people want to consider themselves Biblical Christians, they should base their understanding of God on the Bible wherever the Bible will take them.