In this blog post, I will examine, from a philosophical perspective, why modern Christians seek to prove God’s existence and the significance of striving for harmony between reason and faith.
For modern Christians, proving God’s existence means more than mere intellectual inquiry. The proof of God’s existence is a question closely tied to the essence of faith, and it plays a crucial role in forming and sustaining the foundation of that faith. As a Christian myself, I find this topic fascinating—whether I have attempted such a proof, am currently attempting it, plan to do so, or regardless of the outcome. Efforts to prove God’s existence often deepen an individual’s faith, though they can also lead to a crisis of faith. Among these, the metaphysical proof of God’s existence by the renowned theologian Duns Scotus leaves the deepest impression on me. It explains very well the difference between grasping God’s truth through faith—rather than through reason, which is powerless before it—and what that difference signifies.
However, this raises an important question: Why do modern Christians still attempt to prove God’s existence? Especially in an age dominated by science and technology, there is doubt as to whether faith is even something that can be proven. Many Christians may view the act of trying to prove God’s existence as an arrogant attempt that transcends human limitations. Nevertheless, there are still important reasons for such attempts. The relationship between faith and reason has always been a central theme in Christian theology, and for modern Christians, harmoniously integrating the two has become an even more important task. When rational thought and faith clash, the attempt to prove God’s existence can be seen as part of an effort to understand faith rationally.
Before explaining Duns Scotus’s proof of God’s existence, I would like to discuss the metaphysics he established. Metaphysics is the discipline that investigates being as such. He focused on specific objects such as finite being, infinite being, actual being, and potential being. He believed that terms denoting the fundamental attributes of being—as they apply to created beings—could be analogically and univocally applied to God as well.
Thus, what is important in the process of proving God’s existence goes beyond mere philosophical argumentation; it sheds new light on the relationship between faith and reason. By proving God’s existence, modern Christians seek to confirm that their faith is not merely an emotional belief but can also be justified through reason and philosophical thought. These efforts serve to strengthen individual faith and deepen one’s understanding of God. Duns Scotus’s metaphysical approach does not merely prove God’s existence but demonstrates how reason and faith can work together.
He attached great importance to the principle that everything that exists must be either necessary or contingent—a statement that applies to all existence. This holds true consistently for all that exists. Duns Scotus focused on contingency and distinguished between the moment of nature and the moment of time. He referred to the point where these two moments—the moment of time and the moment of nature—intersect as “simultaneous possibilities.” Since the moment of time continues to exist even as I write this and as the reader reads it, the moment of nature can be viewed as a simultaneous possibility. This simultaneous contingency leads to the assertion of “objective potentiality”—the potential for objects that do not currently exist to come into being. It is said that through this objective potentiality, even objects that do not currently exist are individualized.
Based on this assertion, he reinterpreted the existing concepts of form and matter, arguing that matter exists even without form and constitutes its own essence. This essence may be beyond human perception. Furthermore, form performs the function of individuation in and of itself, independent of substance. Through God’s power, form without matter and matter without form can be created and preserved. Both possess potentiality—the inherent right to be individuated. He uses this objective potentiality to discuss the proof of God’s existence.
Duns Scotus used the concept of causality to prove the existence of the First Cause. For him, the First Cause could be God. For example, if there is something that possesses the capacity to exist, the question arises: what created it? He answers this question by stating that since nothing comes from nothing, there must necessarily be something. Furthermore, since nothing can be its own cause, the answer is that there must be something other than the entity possessing the capacity to exist. An effect can only arise from a cause. Therefore, by identifying the cause of an effect, we can reach the First Principle. However, we fall into the error of seeking the cause that created the entity possessing the capacity to exist—but according to him, such an argument cannot repeat itself indefinitely. Ultimately, he claims to arrive at the First Principle.
He explained the impossibility of such an argument by distinguishing between chains of causation. He distinguished between what is ordered by chance and what is ordered by nature. Let us assume there is a son, a father, and a grandfather. The father is the cause of the son. The father is the cause of the grandfather. It is questionable whether the grandfather is the cause of the son. While a correlation may exist, this does not explain a direct causal relationship. Therefore, Duns Scotus would view the human chain across generations as merely an accidental order. Unlike accidental order, which is horizontal, essential order represents a vertical hierarchical order. For example, suppose a gardener is holding a shovel and moving soil. Without the gardener, the shovel cannot move the soil on its own. Nor can the soil move on its own without the gardener. This demonstrates that the gardener serves as the first principle. Thus, he argues that this represents a vertical hierarchical order in which the chain of causes cannot be traced back infinitely.
This argument has a major weakness: it assumes that we can grasp the objective possibility that God, by His power, can create and preserve as many formless acts and formless acts as He wishes. Furthermore, it is unclear why, in this argument, he posits a multitude of finite first causes (beings) rather than a single, infinite First Cause.
While Aquinas took the causal chain actually existing in the world as the starting point of his argument, Duns Scotus began with the possibility of causality. This was because he wished to present his proof based on purely abstract possibility rather than on contingent facts of nature. He believed that if one started from natural philosophy, one could never transcend the finite world. Duns Scotus also accepts that this argument is possible only if there is no contradiction in the concept of this infinite being. Furthermore, he argues that if there were any contradiction between the concepts of existence and infinity, it would have been discovered long ago.
He would consider infinity to be the most important element in the concept of God. This infinity is not an attribute of God, but a constituent element of divine being. Furthermore, infinity is the characteristic that defines all of God’s attributes. His statement that “by its very nature, it possesses formal perfection as its source and foundation, which is infinity (Oxcn, 4, 3, 1, 32)” implies that God’s attributes can be derived from the concept of infinity.
To summarize Duns Scotus’s proof of God’s existence from a macro perspective, one must first identify objective potentiality and, in order to determine the First Cause, distinguish between the accidental order and the essential order. The essential order allows us to identify the attribute of infinity, through which we can prove God’s existence. This can be regarded as a significant example of medieval theologians’ attempts to harmonize religion and philosophy.
Modern Christians, too, have carried on this tradition and continue to attempt to prove the existence of God. What is important in this process is going beyond mere theoretical argumentation to deepen one’s faith and renew one’s relationship with God. Such proofs can be viewed as part of an effort to gain a deeper understanding of the essence of faith and to integrate it harmoniously with reason. Through these efforts, modern Christians can deepen the roots of their faith and pursue a spiritual life in which reason and faith coexist harmoniously.
