Citation for The Eternity of the World in Islamic Philosophy

Citation styles are based on the Chicago Manual of Style, 15th Ed., and the MLA Style Manual, 2nd Ed..


Adouhane, Yamina . "The Eternity of the World in Islamic Philosophy." In Oxford Islamic Studies Online. Oxford Islamic Studies Online. Jan 27, 2022. <>.


Adouhane, Yamina . "The Eternity of the World in Islamic Philosophy." In Oxford Islamic Studies Online. Oxford Islamic Studies Online, (accessed Jan 27, 2022).

The Eternity of the World in Islamic Philosophy

The debate opposing upholders of the eternity of the world (qidam) to proponents of its origination (ḥudūth) is one of the most vivid controversies in the history of ideas stretching from Greek Antiquity to the Enlightenment and Kant’s critical enterprise which declared the matter rationally unsolvable. Muslim thinkers made no exception and seized upon the issue, consolidating and renewing the arguments for and against, all the while pushing farther than any other thinkers upon the reflection of the compatibility between an eternal world and God as its creator. Islamic philosophers (falāsifah) were influenced by the Greek philosophers from whom they drew some key concepts and arguments. However, the Greek heritage did not alone dictate the terms of the debate: the intense discussions that arose with the mutakallimūn (rational theologians) led both sides to sharpen their arguments and forge new conceptual distinctions.

The Greek Origins of the Debate

The division between eternalists and creationists does not strictly overlap with the distinction between philosophers and theologians, but rather divides philosophers themselves into two groups. This is already true of the Greeks. Although it is difficult to establish what Plato’s doctrine on the matter exactly was, Aristotle and other commentators after him assigned Plato the doctrine of the production of the world by a demiurge, considering that his statement in the Timaeus that the world was generated should be understood in a literal and temporal sense (an interpretation which rendered his doctrine more easily compatible with monotheism). The world is therefore originated, although not in itself corruptible. Aristotle opposed his former master by showing that what is generated is necessarily corruptible and that what has no beginning is incorruptible (De Caelo I, 10–12), and by defending the eternity of the world as it is, both a parte ante (the world has no beginning) and a parte post (the world has no end). He relies, in Physics VIII 1, on proofs from the nature of time (time is composed of instants and each instant or “now” is the intersection of a “before” and an “after,” so that there is always time before and after time) and from the nature of motion (the origination of motion implies the absurdity that there is a motion before the first motion, just as the end of motion implies that there is a motion after the last motion).

The author of the strongest criticisms against Aristotle—at least in regard to their influence on Islamic thinkers—is Philoponus (c. 490–570), a Christian philosopher and theologian, also known by the Arabs as “John the Grammarian” (which was not a laudatory nickname). He forged various arguments based on Aristotelian principles which he turned against the Greek philosopher by showing that they led to logical contradictions (notably on infinity, as will be examined shortly) or internal inconsistencies (e.g., on his conception of celestial bodies). These arguments found a favorable echo among Muslim theologians, but also with the first “philosopher of the Arabs,” al-Kindī (c. 800–870), who was influenced by the Timaeus and defended the origination of the world. On the other hand, the opposite camp, which followed Aristotle and his claim that the world is eternal, gathers the most prominent falāsifah: al-Fārābī (c. 870–950), who was called “The Second Master” after Aristotle; Avicenna (or Ibn Sīnā, c. 970–1037); Avempace (or Ibn Bājja, d. 1139), and Averroes (or Ibn Rushd, 1126–1198), who both lived in al-Andalus; and a number of post-Avicennian thinkers such as Avicenna’s strong advocate, Naṣīr al-Dīn al-Ṭūsī (1201–1274).

Eternity and Infinity

The Posterity of Philoponus’s Arguments

Philoponus’s arguments regarding the impossibility of infinity (available to readers of Arabic through the translation of his treatise Against Aristotle) were particularly popular among those who opposed the eternity of the world. He argued that eternity a parte ante implies an infinite past time and with it an infinite number of movements (be it elementary transformations or celestial revolutions) which lead to a number of contradictions: for the present time and revolution to exist, one must postulate that infinity has been traversed, which is impossible; moreover, every new revolution is added to the infinite number of past revolutions so that infinity is increased, which is also absurd; finally because some revolutions take less time than others, one should affirm that, for instance, Jupiter’s infinite past revolutions are three times more numerous than Saturn’s, which again is contradictory.

The mutakallimūn, both Muʿtazilites and Ashʿarites, used these Philoponian arguments. Even their most famous proof for creation, the proof from accidents, contains in some versions an argument which is similar to Philoponus’s claims from the impossibility of infinity. Indeed the proof is built on three or four theses depending on the version. The first three theses are: the existence of accidents, their origination in time, and the impossibility for bodies or atoms to be devoid of accidents. As the bodies that compose the world cannot exist without or before their accidents and as these accidents come to be in time, the bodies and thus the world must also be originated. This version of the proof is open to the objection that bodies could exist eternally with originated accidents succeeding one another in these bodies perpetually. So a fourth thesis, that of the impossibility of an infinite series of originated accidents, is sometimes added that consolidates the proof against such attacks.

Al-Kindī rejected Aristotle’s dissymmetrical treatment of time and body (the Greek philosopher argued that an infinite body is impossible for it implies an actual infinite, whereas infinite time is not impossible for it only implies a potential infinite) by applying Philoponus’s arguments both to body and time (in his treatise On First Philosophy he gave the argument an axiomatic form). According to him, the world was created by God from nothing and in no time (ibdāʿ). The world therefore has a beginning and will have an end (although eternity a parte post (abad) does not lead to the same contradictions as pre-eternity (azal) for it only implies an ever-increasing finite time so that the world will end not because it must, but because it is God’s will that it ends).

The falāsifah against Philoponus

There was therefore urgency for the Peripatetic falāsifah to answer these attacks and clarify Aristotle’s philosophy from its apparent contradictions. Al-Fārābī and Avicenna set about justifying the specificity of time and past beings which allows an infinite succession of beings in time when bodies cannot be spatially infinite. In a treatise now lost to us, On Changing Beings, al-Fārābī seems to have insisted on the fact that past movements or beings are nonexistent and therefore do not exist simultaneously, and that past revolutions, as an eternal circular motion, are not delimited countable things, so they do not form an infinite number in actuality (Maimonides, Guide of the Perplexed, I 74). Avicenna pushed the distinction further: infinity is impossible only in the case of beings that possess a position (i.e., bodies and magnitude) or an order (i.e., countable things) either according to position (such as the parts of a line or surface or body) or according to nature (such as a series of causes and effects). Thus, all that possesses neither a position nor an order, be it positional or natural, can be infinite without contradiction: past things, because they do not exist simultaneously, are not concerned by this impossibility, and neither are things that exist simultaneously but have no order whatsoever (Avicenna in one of his works gives the example of angels and demons).

Al-Ghazālī (c. 1056–1111), one of the most prominent and influential thinkers of Sunnī Islam, strongly opposed these distinctions in his Incoherence of Philosophers (Tahāfut al-falāsifah), rejecting all kinds of infinity. He added, however, an objection that could not be dismissed even by Avicenna’s distinction: over an infinite time, the human souls that do not cease to exist after they are separated from the body according to Avicenna, must be themselves infinite in number, yet they do exist simultaneously and, al-Ghazālī argues, do have an order, that of their coming into existence in time. In his answer to al-Ghazālī’s refutation, Tahāfut al-tahāfut (The Incoherence of the Incoherence), Averroes simply rejected Avicenna’s conception of the eternity of the individual soul as non-Aristotelian. According to him, Aristotle’s distinction between infinity in actuality and infinity in potency is sufficient to explain why a body must be finite while time can be infinite. Yet he addressed another apparent contradiction (which Avicenna had also tackled before him): Aristotle insisted that an infinite regress of causes is impossible and that there must be a first term, yet his doctrine of the eternity of the world seems to allow for such an infinite chain of causes and effects (for instance that of fathers and sons). Averroes answered by establishing a distinction between chains of essential causes (where the previous link of the chain is a condition of the existence of the next link) and chains of accidental causes (where the fact that a previous link ceases to exist does not impede the next link to exist nor to be the cause of another existent): only the first kind of causal series must be finite, accidental causes on the other hand can and must succeed each other eternally for sublunary beings cannot achieve eternity individually like superlunary beings, but only through an infinite succession. The father is only the accidental cause of the coming into existence of his child, serving as an instrument in the finite chain of causes that goes up to the first cause.

God and the Eternal World

An important difficulty that arises from the assertion that the world is eternal is that it seems incompatible with God being its creator: how can something eternal, meaning its existence has never ceased (lam yazal) and will never cease (lā yazāl), be the act of God? An act, al-Ghazālī insists, is what brings a thing into existence out of nonexistence, and must therefore be preceded by the nonexistence of the thing (Tahāfut al-falāsifah III, p.103). An eternal world cannot strictly speaking be the act of God, even more so as the eternalist philosophers do not conceive the creator as a willing agent who acts by choice, but as a necessitating cause. This question arises for God’s relation both to the world as a whole and more specifically to the celestial eternal beings. In their case, an additional difficulty follows: it may appear as though philosophers are positing other deities next to God, thereby challenging His uniqueness. This issue has a particular resonance in the Islamic context for it echoes a similar discussion among theologians: indeed the Muʿtazilites refused to separate God’s attributes from His essence and defended the creation of the Qurʾān to avoid positing co-eternal entities that could amount to polytheism (shirk).

Avicenna developed a new conceptual matrix precisely in order to distinguish between God and other eternal beings and to insure that God is, in a strong sense, the creator of the world. He famously distinguishes between existence and essence or quiddity and consequently divides existents into possible existents (mumkin al-wujūd), whose essences do not imply existence, and necessary existents (wājib al-wujūd), whose essences imply existence. He also shows that there can only be one existent necessary by essence, and that is God, and that all other existents are possible by essence and rendered necessary by their cause. Thus, eternal beings other than God are dependent on Him for their existence; God alone being without cause, and this dependence is not limited to their coming into existence but lasts for the duration of their existence. Moreover, all existents other than God being caused, they are primarily and by essence nonexistent and only secondarily and by another existent. So that, Avicenna argues, it is true of every existent other than God, whether it has a beginning and an end or exists perpetually, that it is essentially originated and that its existence is preceded by nonexistence, although this anteriority in the case of celestial beings is not temporal but essential. The world is therefore shown to be created by God, creation (ibdāʿ) being understood as a perpetual existentiation (ījād) of the world. Avicenna goes further and affirms that an eternal world, because it implies a perpetual act, enables thinkers to envision a more powerful God.

This conception of God’s relation to the eternal world, which pushes further than ever the attempt to reconcile the apparently incompatible doctrines of the eternity of the world and the creation of the world, will have a strong and determining impact on posterior thinkers in the Muslim world and beyond it. The concept of “eternal creation” along with the correlate concepts of possibility and necessity and the distinction between essence and existence will be at the center of post-Avicennian debates on the eternity or beginning of the world: they will be used by defenders of the eternity of the world, and more interestingly assimilated by Avicenna’s most fervent opponents. So it is true to say that, from then on, Avicenna is the one who dictates the terms of the debate. Theologians such as Fakhr al-Dīn al-Rāzī (c. 1149–1210) will integrate Avicenna’s modal concepts and distinctions into their own proofs from particularization, proving the origination of the world in time from the possibility or contingency of the world and its need of a particularizing agent (mukhaṣṣiṣ) that tips the scales in favor of its existence rather than nonexistence. In so doing, they use Avicenna’s conceptual distinctions against him, as Philoponus turned Aristotle’s principles against him.


On many levels, the question of the eternity of the world appears to be emblematic of Islamic philosophy. It illustrates well the challenges that the falāsifah faced in integrating a foreign conceptual framework: because the doctrine of the eternity of the world was at first sight in contradiction with the teachings of the Qurʾān, it implied a fertile appropriation of this philosophy in order to render it compatible with the Islamic credo. This implied vivid exchanges with the mutakallimūn that participated in the enrichment of the Islamic thought. Finally, on this issue as on others, Avicenna appears to be a turning point that influenced both the falāsifah and the mutakallimūn after him, blurring even more the frontier between them.


Primary Works

  • Averroes. Averroes’ Tahafut al-tahafut (The Incoherence of the Incoherence). Translated by S. Van Den Bergh. London: The E. J. W. Gibb Memorial Trust, 1954. Especially the four first discussions.
  • Maimonides, Moses. A Guide for the Perplexed. Translated by Michael Friedländer. New York: E.P. Dutton, 1904. Especially I 73–74.

Secondary Works

  • Dales, Richard C. Medieval Discussions of the Eternity of the World. Leiden, Netherlands: Brill, 1990.
  • Davidson, Herbert A. Proofs for Eternity, Creation and the Existence of God in Medieval Islamic and Jewish philosophy. New York: Oxford University Press, 1987.
  • Michon, Cyrille. Thomas d’Aquin et la controverse sur l’éternité du monde. Paris: GF-Flammarion, 2004.
  • Wolfson, Harry A. The Philosophy of the Kalam. Cambridge, Mass., and London: Harvard University Press, 1976. Especially chapter 5.

© Oxford University Press 2007-2008. All Rights Reserved