Natural theology is traditionally distinguished from revealed theology. Natural theology is concerned with knowledge about God’s existence and nature that is available to us via the use of our natural cognitive faculties, such as by way of philosophical arguments. It does not require an appeal to any special divine revelation, whether embodied in scripture, the teachings of a prophet backed by miracles, or what have you. There might happen to be teachings in some source of special divine revelation that overlap with the deliverances of natural theology, but what makes something a matter of natural theology is that it can at least in principle be known apart from that.
Revealed theology is concerned with knowledge about God that is available by way of some special divine revelation, distinct from anything we know by philosophical arguments or the like. It has a source that is supernatural in the sense of being beyond what the natural order of things is capable of producing. That is why a miracle (a suspension of the natural order) is, in Catholic theology, taken to be a necessary condition for our knowing that something really has been divinely revealed. The content of revealed theology might include matters that are also knowable by way of natural theology, but typically it involves matters that could not in principle be known that way.
To illustrate, an argument from motion to the existence of a divine prime unmoved mover would be an example of natural theology. You don’t need scripture or the guidance of a prophet or the Church in order to construct such an argument, which is why a pagan thinker like Aristotle could discover it. By contrast, that there is more than one Person in God (the doctrine of the Trinity) is an example of revealed theology. We can know it only because it has been specially revealed, where the genuineness of the revelation is backed by miracles (such as Christ’s resurrection). The doctrine of divine simplicity would, according to Catholic theology, be an example of something that we know both from natural theology and revealed theology. It is knowable by purely philosophical arguments, which is why it could be arrived at by pagan thinkers like Plotinus. But it is also a dogma of the Church, in the sense of being a teaching that Catholicism holds to have been taught infallibly under divine guidance.
Now, though in the abstract this distinction is clear and neat, in practice matters of natural and revealed theology can have a great influence on each other, and the boundaries between them are not always sharp. Sometimes this is because revealed theology influences natural theology. How could that be? Well, natural theology, like any other human enterprise, can involve error. For example, Plotinus correctly reasons to the conclusion that God must be simple or non-composite, but wrongly concludes that this rules out attributing to him anything analogous to intellect. Hence he locates intellect in a secondary divine hypostasis. The Catholic theologian guided by divine revelation would judge this to be an error of philosophical reasoning, and argue that in fact it is a matter of sound natural theology that both simplicity andintellect must be attributed to God.
You might think this is a cheat, but it is not. For one thing, the Catholic theologian would give philosophical arguments for the conclusion that there is intellect in God – that is to say, arguments that in no way appeal to divine revelation, but only to purely philosophical considerations. For another thing, even some pagan philosophers (such as Aristotle) would agree on attributing both simplicity and intellect to God. Hence, appeal to divine revelation is not necessaryfor attributing both simplicity and intellect to God, even if it might guide this or that individual thinker in arriving at that conclusion. It is not like the doctrine of the Trinity, which could not be arrived at on purely philosophical grounds.
Having said that, natural theology can guide the way that revealed theology is articulated. For example, though the doctrine of the Trinity could not have been known through purely philosophical arguments, once we have it in hand as a result of divine revelation, philosophical analysis can affect how we understand it. For example, it might tell us that such-and-such a way of formulating the doctrine must be wrong, because the formulation would entail polytheism, and polytheism can be known to be false both as a matter of natural theology and as a matter of revealed theology. Or we might find that certain philosophical concepts and terminology (substance, essence, etc.) are indispensable in articulating the doctrine.
Given that grace builds upon nature rather than destroying it, we should expect that matters of supernatural or revealed theology and matters of natural theology are in practice closely interwoven even in the sources of divine revelation, and that is indeed what we find. For example, the law given through Moses contains many components that are matters of natural law (such as the commandments against murder, stealing, and adultery) in addition to components that are matters of temporarily operative special divine law (such as the sacrificial system). Catholic doctrinal definitions taken to be protected from error by way of special divine assistance sometimes incorporate terminology having a philosophical provenance (such as “transubstantiation,” or the characterization of the soul as the “form” of the body).
Now, all of this is intended as stage-setting for an explanation of the concept expressed in the title of this post. What do I mean by “preternatural theology”? What is preternatural is what is beyond the power of some part of the natural order to produce, and yet is not strictly supernatural insofar as it can be caused by some other part of the created order and not only by God.
A stock example would be the phenomena associated with demonic possession. Take the strange abilities exhibited by the Linda Blair character (or rather, by the evil spirit possessing her) in the movie The Exorcist– suddenly speaking in languages previously unknown to her, levitating above her bed, causing objects in her room to move without touching them, etc. There is an obvious sense in which these are not natural. In the ordinary course of events, these things don’t happen and people don’t have the power to make them happen. On the other hand, they are in various respects not strictly supernatural either. For one thing, they are not miracles, insofar as God is not the one making them happen. For another, they are not all of themselves naturally impossible (for example, there is nothing per se impossible about a person speaking Latin, even if the Linda Blair character shouldn’t have been able to do it). And they are produced by a demon, who is part of the natural order broadly construed just as much as we are. The created world includes the angels and demons, and thus what they do is not of itself supernatural in the sense of being beyond the natural order altogether.
Now, the possibility and indeed reality of a purely natural theology is something commonly and traditionally affirmed in Catholic teaching. Human beings completely outside the orbit of Christian revelation can and sometimes do have at least an imperfect knowledge of God. And yet scripture tells us that “all the gods of the Gentiles are devils: but the Lord made the heavens” (Psalm 95:5, Douay-Rheims version), and that “the things which the heathens sacrifice, they sacrifice to devils, and not to God” (1 Corinthians 10:20). How can these claims be reconciled?
The way they can be reconciled is by seeing that just as truths of natural theology and truths of revealed theology are often intermixed, so too can truths of natural theology and errors of what we might call preternatural theology be intermixed.
Hence, consider religions like Hinduism and Islam. Hinduism features the worship of multiple deities, such as Vishnu and Shiva, and both the fact of this multiplicity and some of the details of the cults of these gods are simply incompatible with Christian doctrine. At the same time, there is an impressive philosophical tradition within Hinduism that includes both arguments for the existence of a divine creator and the teaching that there is a single ultimate divine reality of which the multiple deities are only manifestations. Islam claims to be based on a special divine revelation, and that too is a claim that no Christian can accept. But Islam too has an impressive philosophical tradition that includes powerful argumentation concerning the existence and attributesof God.
Someone could consistently both hold on scriptural grounds that the distinctive theological claims of such religions have a diabolical preternatural provenance, and allow that the errors due to that provenance are nevertheless intermixed with truths of natural theology. A message might seem to be from God while in fact being from the devil, and yet a person who wrongly accepts that message might also have some genuine knowledge about God by way of independent philosophical arguments. A pseudo-revelation can be mixed in with truths of natural theology, just as a genuine revelation can be mixed in with truths of natural theology.
There are two extreme views to be avoided, then. One error (made by some traditionalists) would be to suppose that, because a certain non-Christian religion is based on a pseudo-revelation, its adherents cannot have any genuine knowledge of God of a natural theology sort. The other error (made by some liberals) would be to suppose that, because adherents of a certain non-Christian religion evidently do have some genuine knowledge of God of a natural theology sort, that religion’s purportedly revealed doctrines must really be at worst merely confused expressions of this natural theology and therefore more or less innocent. In other words, the propositions:
(1) Religion R contains some false theological beliefs of diabolical origin, and
(2) Religion R contains some true theological beliefs grounded in natural theology
are consistent with one another. One cannot appeal to (1) as a reason to reject (2) and one cannot appeal to (2) as a reason to reject (1). This is important to keep in mind when considering issues such as whether adherents of different religions are talking about the same thing when they use the word “God.”
Further reading: