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The Case for Natural Theology

Though some modern critics scoff at the idea, we can learn a great deal about the nature of God strictly through the use of our senses.

Trent Horn

Can human reason alone tell us anything about God? Or does sin make us so stupid that we can’t know anything about him? These are some of the questions that drive the contemporary debate about natural theology. 

This is a branch of theology that explores what can be known about God using reason. Eastern Orthodox philosopher Richard Swinburne describes natural theology as the task of reasoning about God “from propositions which theist and atheist alike can recognize as obviously true” (Natural Theology in the Eastern Orthodox Tradition).  

The Catholic Church has long endorsed the validity of natural theology, and the First Vatican Council infallibly declared, “If anyone says that the one, true God, our creator and lord, cannot be known with certainty from the things that have been made, by the natural light of human reason: let him be anathema.” 

Nevertheless, some Christian traditions have been skeptical of natural theology. Some Protestants say our enslavement to sin has degraded our minds so much that we cannot naturally reason to the existence of God. Modern Greek theologians in the Eastern Orthodox tradition have said that the traditional way of coming to know God exists is not through the arguments of natural theology (such as proofs for the existence of God) but through direct experience of God in prayer or mystical experiences.  

And while these criticisms have valid points, none of them disprove the validity of natural theology and its ability to help us come to know at least some truths about the existence and nature of God. 

A history of natural theology

Let me be clear that people can come to know God through other means, such as religious experience. In addition, human reason can’t cause us to desire God’s offer of salvation for its own sake. The Catechism of the Catholic Church puts it this way:  

Man’s faculties make him capable of coming to a knowledge of the existence of a personal God. But for man to be able to enter into real intimacy with him, God willed both to reveal himself to man and to give him the grace of being able to welcome this revelation in faith. The proofs of God’s existence, however, can predispose one to faith and help one to see that faith is not opposed to reason (35).

The value of these arguments can be seen in the witness of the Church Fathers, the apostles, and our Lord Jesus Christ himself.  

First, there are arguments for the existence of God from the design we perceive in the universe. St. Paul declared in Romans 1:20, “Ever since the creation of the world, his invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made.” Many scholars agree Paul is drawing from the deuterocanonical book of Wisdom, which says, “From the greatness and beauty of created things comes a corresponding perception of their Creator” (13:5). 

The Church Fathers expanded on these arguments from design. St. Maximus the Confessor wrote, “The saints learned of the Creator’s existence from the things created by him” (Ambigua, 10). Design arguments can also be found in the writings of Clement of Alexandria, Theophilus of Antioch, Augustine, and other Church Fathers, though with different illustrations.  

For example, St. John Chrysostom said that just as a ship can’t go a mile without a crew, the universe could not be ordered without a supreme intelligence guiding it. St. Basil the Great said, “The world is a work of art displayed for the observation of all people, to make them know him who created it” (Hexameron 1.7). 

Before we continue, you should know I’ve cited primarily Fathers in the Eastern tradition of the Church in order to dispel the notion that natural theology is solely a product of the Western tradition of the Church (e.g., Augustine, Aquinas, etc.) 

Gregory the Theologian gives an argument like the modern fine-tuning argument that holds the laws of nature are not the product of chance or necessity, so they must have been designed. Gregory said of the world:  

Do these belong to chance, or to something else? Surely not to chance. And what can this “something else” be but God? Thus, reason that proceeds from God . . . leads us up to God through visible things” (Oration 28.26). 

St. Gregory of Nyssa said: 

Should he say there is no God, then, from the consideration of the skillful and wise economy of the universe he will be brought to acknowledge that there is a certain overmastering power manifested through these channels (Great Catechism, Prologue).

Natural theology can not only help us see that God exists, but it can also help us determine what God is like, including that there is only one God. Again, Gregory of Nyssa: 

If, on the other hand, he should have no doubt as to the existence of deity but should be inclined to entertain the presumption of a plurality of Gods, then we will adopt against him some such train of reasoning as this [which include arguments for monotheism] (Ibid.).

In the early Fathers, we also see the development of cosmological arguments for the existence of God or arguments from the existence of the universe itself. Although some people identify these arguments solely with medieval theologians such as St. Thomas Aquinas, their basic elements can be found centuries earlier.  

For example, St. Maximus the Confessor said, “Nothing moves without a cause, then no being is unmoved except the prime mover” (Ambigua 10.88). St. John of Damascus said: 

For everything that is moved is moved by another thing. And who again is it that moves that? And so on to infinity till we at length arrive at something motionless. For the first mover is motionless, and that is the deity (An Exposition of the Orthodox Faith 1.4).

According to theologian Thomas Torrance, “It was in fact on the foundations laid by John of Damascus that Western thinkers like St. Thomas based their natural theology” (The Ground and Grammar of Theology, 79). 

You can also find evidence of an argument from miracles (see sidebar below) and the beginning of a moral argument for God’s existence. A biblical example of the latter is Romans 2:14-15, where Paul says Gentiles who don’t have the Mosaic law “show that what the law requires is written on their hearts while their conscience also bears witness.”  

St. Athanasius argues in a similar way, saying of idolaters, “For neither was the law for the Jews alone . . . they were for all the world a holy school of the knowledge of God” (On the Incarnation, 12). Athanasius even said in the same passage that the holiness of the saints could be sufficient evidence that God exists.  

Presupposing God exists

You may be wondering, how would Christians who reject natural theology make a case to unbelievers that God exists? Some of them say everyone believes God exists, and people who claim to be atheists are lying to us or to themselves. But this doesn’t seem to account for the existence of atheists who genuinely seem to want God to exist but have simply not been convinced of his existence. 

Others say it is more appropriate for Christians to start with the presupposition that God exists and show that it is impossible for human beings to have knowledge or morality unless this is true. This approach to demonstrating the existence of God has been called presuppositionalism, but there are significant problems with this view. 

First, if a presuppositionalist says that things such as knowledge, logic, or morality exist and only the presupposition of God’s existence explains their existence, then this is really just a variation of natural theology. In this case, the presuppositionalist must give arguments that show (1) logic, morality, and knowledge really do exist, and (2) they have no natural explanations but only a supernatural explanation. 

However, if a presuppositionalist says we just must start with the God of Christian theism to understand anything at all, then he’s basically saying we must start with the Creator and use that to show knowledge is possible, and so this is the only way we can know the Creator exists.  

But as the Christian philosopher William Lane Craig says, “Presuppositionalism is guilty of a logical howler: it commits the informal fallacy of petitio principii, or begging the question, for it advocates presupposing the truth of Christian theism in order to prove Christian theism” (Apologetics: Five Views, Kindle version). 

We know this is the case because we could ask the Christian presuppositionalist why someone couldn’t start with one of the following presuppositions instead of Christian theism: 

  1. Atheistic nihilism, which says we are mistaken and that we actually live in an illogical, amoral, unintelligible universe
  2. Atheistic Platonism, which says logic, knowledge, and morality are abstract concepts or unexplained brute facts
  3. Polytheism or non-Christian monotheism such as Judaism or Islam
  4. One of the many forms of Christian theism a presuppositionalist might disagree with, such as Calvinist presuppositionalism or even presupposing the Catholic view of God, which many presuppositionalists also reject

And once again, the dilemma raises its ugly head. If the presuppositionalist offers arguments that claim these other presuppositions don’t work, and only his theology explains the world, then he’s doing natural theology, albeit in a strange, backward sort of way. But if he simply asserts that his brand of theism must be our starting point, then he’s making an invalid argument that we need not take seriously, since it assumes the very thing it is trying to prove. 

Objections to natural theology

One objection to natural theology is the claim that there is no such thing as generic theism for natural theology to prove. According to this view, a person must believe that God is either the triune God of Christianity (or even the God of a certain denomination of Christianity) or else he is simply an ignorant heretic.  

But that’s false. Faithful Jews who lived before Christ knew God existed even though they didn’t know God was a Trinity. People can use reason to know God exists even if they are mistaken about his nature. Aristotle knew, and I know, water exists, but of the two of us, only I know water is H20. Likewise, Aristotle knew, and I know, one God exists, but I know the further truth that this God is Father, Son, and Holy Spirit.  

Second, there is the claim that natural theology is faulty because it doesn’t tell us in which God to believe. But that’s not true, since we can reason to God’s attributes based on what we observe in creation. The argument from motion, for example, shows God is infinite; necessary; simple; one; immutable; and perfect in goodness, knowledge, and power. One can also combine arguments to show God is a personal being who designed the universe and is the standard of moral goodness itself. Finally, miracles show the Christian God has revealed himself (see sidebar below).  

Moreover, this objection would undermine presuppositionalism, because that method of showing God exists doesn’t tell us which God’s existence we should presuppose. And, as I said before, if the presuppositionalist gives arguments to support his presupposition over others, then he’s doing natural theology. 

Third, there is the claim that sin has damaged the human intellect so much that we can’t know anything about God apart from God revealing himself to us. And while it is true we couldn’t know God’s saving plan or his triune nature apart from revelation and the gift of faith, we can still know some basic truths about God. As Paul said to some Greeks: 

Men of Athens, I perceive that in every way you are very religious. For as I passed along, and observed the objects of your worship, I found also an altar with this inscription, “To an unknown god.” What therefore you worship as unknown, this I proclaim to you (Acts 17:22-23).

In this incident Paul acknowledged that the Greeks used reason to correctly arrive at the truth that God exists, but they were ignorant of God’s saving nature. Even the synod of Dort (1619), which helped formalize the basic tenets of Calvinism, declared: “There is, to be sure, a certain light of nature remaining in man after the fall, by virtue of which he retains some notions about God.” 

Fourth, some critics say natural theology pales in comparison to what we can know about God via religious experience. In one sense, this is true. I’m more confident Yosemite National Park exists when I experience it for myself than from what I can learn from other people’s testimony about it. But I could still show someone else who hasn’t seen Yosemite that it does exist through indirect ways of knowing the park, such as photographs and maps.  

In fact, the maps I show the person might provide knowledge of Yosemite neither of us can get through direct experience, just as natural theology can help us better understand God’s specific attributes than what I can know through a religious experience. Moreover, objective natural theology breaks the stalemate that occurs when different religions offer similar subjective religious experiences as proof of their doctrines. 

Not only is there no good reason to abandon natural theology, but there are also many good reasons to continue engaging in this sound, philosophical project so that we may, as 1 Peter 3:15 says, “Always be prepared to make a defense to any one who calls you to account for the hope that is in you, yet with gentleness and reverence.” 


The Argument from Miracles

The Old Testament prophet Elijah demonstrated the superiority of Yahweh by challenging the prophets of Baal to a miracle contest. Our Lord told his critics, “If I am not doing the works of my Father, then do not believe me; but if I do them, even though you do not believe me, believe the works, that you may know and understand that the Father is in me, and I am in the Father” (John 10:37-38).  

Jesus is saying that even if you don’t believe his words, his miraculous deeds should be enough evidence to show he is the Messiah. In 1 Corinthians 15:3-8, Paul presents a list of witnesses of Christ’s resurrection to answer doubts people had about the general resurrection. He also noted that some of them were still alive, presumably so others could examine them. St. John of Damascus said arguments for God are necessary for people who didn’t witness miracles firsthand and experience power to convert. He wrote: 

“But since the wickedness of the Evil One has prevailed so mightily against man’s nature as even to drive some into denying the existence of God, . . . so the disciples of the Lord and his apostles, made wise by the Holy Spirit and working wonders in his power and grace, took them captive in the net of miracles and drew them up out of the depths of ignorance to the light of the knowledge of God” (An Exposition of the Orthodox Faith 1.3). 

Finally, the First Vatican Council declared infallibly, “If anyone says that miracles can never be known with certainty, nor can the divine origin of the Christian religion be proved from them: let him be anathema.” 

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