Proving God’s Existence in Fārābī’s Works

Introduction
From Fārābī’s perspective, one of the most important, and perhaps the most pivotal, aspects of metaphysics is the discussion of theological issues—namely, the study of God as the origin of the universe and His attributes. Fārābī often defines metaphysics in his works in terms of theology, describing it as the study of the first existent and other existents insofar as their existence is caused by the first existent.
Thus, in Fārābī’s view, God is not only the existent on whom all other existents depend, but other existents merit metaphysical examination only insofar as they are connected to God. Therefore, a proper understanding of the first existent, His attributes, and His relation to other existents is among the most important and pivotal research issues in the study of Fārābī. While the first existent and His attributes have been discussed in another article (Kiankhah 2022b), due to its limited scope, that article did not address the proof or proofs for the existence of God in Fārābī’s view—an essential issue in Fārābī’s theology. In continuation of my research on Fārābī’s theology, this article primarily focuses on the proof or proofs for God’s existence in Fārābī’s works. It analyzes and examines Fārābī’s approach to proving God’s existence and addresses a crucial philosophical question that has concerned thinkers for a long time: Why does God exist?
In the fourth chapter of Iḥṣāʾ al-ʿulūm (Enumeration of the Sciences), which is dedicated to natural science and theology, Fārābī divides theology (metaphysics) into three parts. The first addresses existents and their accidents insofar as they are existents. The second deals with the preliminaries of proofs and the definition of substances (primitive definitions), while the third is devoted to the study of existents that are neither physical nor associated with physical objects. Fārābī then outlines the general issues of this third part, mentioning the proofs presented for its problems, such as the proof for the existence of detached (immaterial) existents, the proof for the multiplicity of detached existents, the proof for the finitude of detached existents, and the proof for the hierarchical degrees among these existents, where this hierarchy ultimately leads to an existent that is the most perfect, free of any imperfections, and from which other existents derive their existence, unity, and truth (Fārābī 1996, 75–79).
According to this text, Fārābī holds that the existence of the first existent and non-physical existents is not self-evident. Thus, a key problem in theology (metaphysics) is to prove the existence of immaterial beings and demonstrate that the hierarchical chain of these beings culminates in the first origin. Like Avicenna, Fārābī does not consider God’s existence self-evident and regards the proofs for His existence as a metaphysical issue. However, a closer examination of Fārābī’s works reveals that his approach to proving the first existent is more complex than Avicenna’s, requiring deeper scrutiny.
Research Methodology
As with other research on Fārābī, it is essential, before embarking on a study, to distinguish between the works attributed to him in terms of their authenticity and then examine their content. Regarding the central issue of this article, there are profound and fundamental differences between the authentic and non-authentic works attributed to Fārābī, and failing to distinguish them would result in a conflation of various views and imprecision in reporting and analyzing Fārābī’s thought. As I suggested in the article “The First existence and its attributes in Fārābī’s view” (Kiankhah, 2022b), many historical books and research papers have attributed the ideas presented in treatises such as al-Daʿāwī al-qalbiyya, Sharḥ risālat Zīnūn al-kabīr, and ʿUyūn al-masāʾil to Fārābī without scrutinizing their authenticity, simply because these treatises contained significant material on theology and proofs of God’s existence. However, these treatises often align with an Avicennan intellectual approach. The author or authors of these three treatises, and similar works, emphasize the distinction between existence and quiddity, as well as necessity and possibility, proving God’s existence based on possibility and necessity. In contrast, an examination of the views presented in the definitively authentic works of Fārābī shows that, unlike Avicenna, he did not consider the distinction between essential necessity and essential possibility in his metaphysics, and, in fact, he never describes God as the Necessary Existent (wājib al-wujūd).
Thus, when examining the proofs for God's existence in Fārābī’s view, it is crucial to consider such proofs separately in his definitively authentic works and in more doubtful ones, in order to avoid conflating the differing views presented in these two groups of writings.
Contributions and Results
Overall, after examining the proofs for God’s existence in the works attributed to Fārābī, the following points can be noted.

An examination of Fārābī’s works reveals that those doubtfully attributed to him present clear-cut proofs for God’s existence based on the distinction between existence and quiddity, as well as necessity and possibility. The fact that these proofs are grounded in principles that contradict Fārābī’s theoretical foundations, along with other evidence in the texts, strengthens the hypothesis that these works were not authored by him. Many researchers, without acknowledging this, have cited these works to argue that Fārābī was the first philosopher to view God as the essentially Necessary Existent and to present the proof from necessity and possibility for God’s existence, thus rejecting Avicenna’s role as the originator of these arguments.
A review of Fārābī’s definitively authentic works reveals that al-Ḥurūf, Taḥṣīl al-saʿāda, Falsafa Arasṭūṭālīs, and Fuṣūl muntazaʿa contain a version of the causal proof for the existence of the first existence when establishing the necessity of the third branch of the theoretical sciences, namely theology.
While Ārāʾ ahl al-madīnat al-fāḍila and al-Siyāsat al-madaniyya contain the most extensive theological discussions among Fārābī’s works and provide detailed presentations of the proof from the unity of the first existent and the proof from the negation of opposites, they do not explicitly offer a clear-cut proof for the existence of the first existent. However, there are passages in Ārāʾ ahl al-madīnat al-fāḍila where it appears that Fārābī seeks to establish the existence of the First Existence through an analysis of its essence.
It seems that the reason Fārābī does not present a proof for God’s existence in his two major works, Ārāʾ ahl al-madīnat al-fāḍila and al-Siyāsat al-madaniyya, is that he assumes God's existence, having already somewhat established it in Taḥṣīl al-saʿāda and similar works. Thus, he begins his discussions with an explanation and analysis of the problems concerning God and higher principles. In Taḥṣīl al-saʿāda, he emphasized the necessity of addressing theology without fully engaging with it.
One contribution of this article is the examination of evidence for rejecting the attribution of three treatises to Fārābī: ʿUyūn al-masāʾil, al-Daʿāwī al-qalbiyya, and Sharḥ risālat Zīnūn al-kabīr. This helps researchers of Fārābī avoid errors in attributing philosophical views to him and accurately assess Avicenna’s innovations in presenting proofs for God’s existence.