Defended in the summer of 2019 at HU Berlin, Nicholas Aubin’s revised doctoral dissertation takes readers deep into the fourth/tenth and early fifth/eleventh centuries, and successfully introduces them to ‘three innovators between Philoponus and Avicenna’, as the subtitle has it. The three innovators are the Muslim scholar Abū l-Ḥasan Muḥammad b. Yūsuf al-ʿĀmirī (d. 381/992) and his two Christian colleagues, Abū Sahl al-Masīḥī (d. 401/1010) and al-Ḥasan b. Suwār b. al-Ḫammār (d. after 407/1017).
Two of them have received at least intermittent attention: al-ʿĀmirī in the work of Elvira Wakelnig (notably her 2006 monograph Feder, Tafel, Mensch), Everett K. Rowson, and Robert Wisnovsky, particularly in connection with his anticipation of the Avicennian notion of a ‘necessary of existence in itself’; and Ibn Suwār in the publications of Hans Daiber, Paul Lettinck, and Fedor Benevich as an important link in the history of meteorology, and above all as a member of the increasingly famous Baġdād Peripatetics (now under scrutiny in a research project at LMU led by Peter Adamson). By contrast, Abū Sahl was known, if at all, to a narrow circle of specialists in the history of medicine; as a philosopher he has been almost entirely overlooked, save for Hans Hinrich Biesterfeldt’s investigation into Arabic classifications of the sciences, which included a work by Abū Sahl that subsequently caught the interest of Dimitri Gutas. The situation changes now – indeed, has changed – owing to an ongoing research project (led by the present reviewer) that will produce a monograph on Abū Sahl and, more specifically relevant here, to Aubin’s book.
Aubin devotes a chapter to each of his three innovators, and one each to the two poles of his study: Philoponus and Avicenna. The book is framed by an introduction, a brief conclusion, and an appendix featuring a translation of excerpts from Abū Sahl’s treatise on the pulse. Readers gain valuable insights from Aubin’s thoughtful analyses of a crucial period in the history of philosophy and the sciences – a period significantly shaped by Philoponus’ readings of, and engagements with, Aristotle, which generated paradigms that are striking in themselves and left a lasting imprint on the towering figure of the Arabic philosophical tradition: Avicenna.
Although Aubin presents the monograph as an engagement with Aristotle’s ‘Finite Power Argument’ in Physics VIII.10 – that a finite body does not possess infinite power – the book, to my mind, works best as a collection of five largely independent research articles rather than a unified monograph with a sustained argumentative progression. Many themes are cosmological and, in some way, related to the ‘Finite Power Argument’, but the volume’s real strength lies in presenting three highly interesting philosophers and taking welcome steps towards appreciating them on their own terms. Aubin’s repeated effort to show how the chapters on al-ʿĀmirī, Abū Sahl, and Ibn Suwār contribute to the history of the ‘Finite Power Argument’ feels more like a remnant of the book’s origin as a PhD dissertation, where a clear thematic spine is often required. This is not so much a criticism as advice to readers: Aubin’s book also rewards selective reading and, in fact, may even work better that way.
The first chapter addresses Philoponus and his understanding of dynamis. The texts under scrutiny are his famous Contra Proclum and the Physics commentary, along with reports from his rival and contemporary Simplicius – reports that may derive from an independent treatise by Philoponus on the ‘Finite Power Argument’. To these Greek materials Aubin adds a short consideration of an Arabic work that, according to Herbert Davidson, is a summary of that treatise.
A central claim established by Aubin is that Philoponus employs dynamis in two ways: as a quantifiable power, and as a non-quantifiable potentiality (with the related notions of possibility and contingency). As Aubin argues, the former is dominant in Philoponus’ extant writings, while the latter appears in the testimony provided by Simplicius. Keeping these connotations distinct is crucial, even if, as Aubin shows, both ultimately reinforce the claim that Philoponus is first and foremost engaged with showing that the world is intrinsically perishable (and that the argument for the world’s coming-to-be – which conceptually exceeds mere perishability – relies on additional premises). The subtlety Aubin discerns in the Greek texts is, he argues, absent from the Arabic summary, which he calls ‘a later work of somewhat coarser polemic’ (42), yet which nevertheless enjoyed wide reception among Muslim, Christian, and Jewish intellectuals.
This last point leads naturally to the second chapter, focused on a treatise by Ibn Suwār arguing that the argument for the world’s origination by Yaḥyā al-Naḥwī (i.e., by ‘John the Grammarian’ or John Philoponus) is preferable over the argument offered by the theologians. The latter is the familiar kalām argument for the existence of God, which moves from the existence and origination of the world to the need for an originator, thus establishing that originator’s existence. Aubin shows well how Ibn Suwār’s case rests on the distinction between essential and accidental predication, integrating themes from Aristotle’s Posterior Analytics. In Ibn Suwār’s view, the kalām version either is unaware of this distinction or mishandles it by relying on accidental features, whereas the Philoponian reasoning proceeds from essential predicates constitutive of the world’s essence.
One particularly interesting section is Aubin’s analysis of the Arabic term sarmadī. Surveying several authors, he argues that its meaning oscillates between ‘everlasting’, especially when applied to motion and time, and ‘imperishable’ when applied to ‘substances like the Forms, the cosmos, or the heavenly bodies’ (75), and that the latter is at play here. There is much merit in this investigation, even if it treats only the tip of the iceberg and does not quite register its limits. For instance, the fact that sarmadī also frequently corresponds to aiôn remains unmentioned, as are accompanying connotations of atemporality – both of which could have been mobilised to support the claim that ‘everlasting’ is ill-suited in the context of the world’s origination (even though I remain unconvinced that ‘imperishable’ is, in fact, the best choice then).
Chapter three turns to al-ʿĀmirī, with special emphasis on a mature work, The Determination of the Various Aspects of Predetermination, which becomes the chapter’s central, almost exclusive, focus. While it is valuable to learn more about this text, the decision to concentrate on it yields long stretches that are little more than paraphrase and explanation of translated excerpts, with limited effort to provide broader historical or philosophical contextualisation. This is particularly true of the first half; the second half (from Section 3.3 onwards) more convincingly demonstrates how al-ʿĀmirī’s thought connects to the Aristotelian commentary tradition. Although Aubin’s treatment does not really extend beyond Aristotle and Philoponus, he succeeds in underscoring, once again, Philoponus’ central importance for the philosophical milieus in and around Baġdād in the fourth/tenth century, in keeping with the book’s subtitle (e.g., 131–144).
Given the attention to convergences between Philoponus and al-ʿĀmirī, one missed opportunity is the unresolved question of whether Simplicius’ commentary on the Physics was known in the Islamic world in general, and to al-ʿĀmirī in particular. Aubin would have been well placed to contribute to that debate. The chapter nonetheless offers a wealth of information on the Determination – on possibility, teleology, divine providence, and power – though at times the focus on human free will seems to eclipse the book’s stated concern with the ‘Finite Power Argument’.
The fourth chapter treats Abū Sahl al-Masīḥī, aptly introduced as ‘a figure of immense importance in the history of Arabic medicine’ (161) whose philosophical profile should not be reduced to his role as Avicenna’s companion and teacher, notable though that is. Beyond his medical magnum opus, Abū Sahl left behind a unique manuscript, now housed in the university library in Leiden, containing four philosophical works and a brief chapter on the pulse. Two of these works centre on themes from Aristotle’s De caelo (one is a short commentary or ‘summary’ as Aubin translates talḫīṣ), one relates closely to the Physics, and the last offers crucial insights into Abū Sahl’s views on the interrelation of the sciences and the philosophical curriculum of his time. While the latter theme has drawn some prior attention, Aubin now emphasises the value of the other three texts, and insightfully integrates the chapter on the pulse into his account of Abū Sahl’s handling of the ‘Finite Power Argument’.
Aubin begins with the well-known issue of the skopos of Aristotle’s De caelo, asking how Abū Sahl addresses it in his Classification of the Philosophical Sciences. Notably, Abū Sahl describes both metaphysics and physics as ‘universal sciences’. According to Aubin, this implies that both treat the same set of objects – all that exists, including the first cause – though physics addresses the first cause only partially, with metaphysics covering the remainder; conversely, metaphysics does not encompass all aspects of material things examined in physics. The result appears to be an attempt at a neat division of labour, even though it does not come without its own ‘interpretive problem[s]’, as Aubin stresses (173–175).
Turning to Abū Sahl’s two works on De caelo, Aubin stresses their different approaches. One is a faithful summary that explicitly aims not to ‘deliberately misrepresent’ (176) Aristotle’s views, though it often omits parts to achieve brevity; the other straightforwardly revises De caelo, omitting and rejecting some of its central components. Aubin convincingly shows that Abū Sahl was aware of his divergence from Aristotle regarding De caelo – and he uses this observation as a guide in his reading of Abū Sahl’s treatise on the Physics. In fact, in the Principles of Natural Beings, Abū Sahl shows a number of discrepancies to Aristotle without, however, explicitly flagging his departures as he did in his works on De caelo. One notable feature for instance is the omission of the first cause, normally the culmination of Aristotle’s Physics; instead, Abū Sahl explains heavenly motion by appeal to the unique nature of celestial bodies rather than their souls or an external – metaphysical – mover.
Overall, Aubin’s treatment of Abū Sahl provides a valuable initial guide to this teacher of Avicenna but is constrained by the book’s renewed focus on the ‘Finite Power Argument’. Aubin concludes that ‘the Pillars and Principles of Natural Beings prefigure, in terms of style, content, and method, the treatises contained in the natural-philosophical portions of Avicenna’s Šifāʾ’ (210). The precise modalities of this prefiguration remain to be shown in detail, and Aubin’s fifth and final chapter moves in that direction.
That final chapter is likely to become the most frequently read and cited, as Aubin explores the ways his three innovators may have influenced subsequent philosophical traditions, particularly Avicenna. A full reckoning with his claims would require more space than a short review allows, but he succeeds in identifying a number of intriguing points that merit further exploration in future work.
In sum, Aubin’s monograph is a valuable study of three intellectuals who have long been overshadowed by Philoponus on the one side, and Avicenna on the other. Its chapters can be read profitably in any order, and they offer helpful starting points for future work on al-ʿĀmirī, Abū Sahl, and Ibn Suwār. That said, the thematic frame of the ‘Finite Power Argument’ is not always the most convincing thread: there are extended stretches where the theme recedes almost entirely, while elsewhere it constrains the exploration of the three innovators, making it difficult to grasp them fully as thinkers in their own right, and, indeed, as the innovators they were. Aubin also does not always integrate the full range of secondary literature available or engages with the current state of the art. On the side of primary texts, too, the focus falls a little heavily on Aristotle and Philoponus – presumably a further remnant of the dissertation’s original design of the monograph as a PhD thesis on the ‘Finite Power Argument’ – though the resultant book has perceptibly evolved beyond that initial idea. None of this, however, detracts from Aubin’s significant contribution: he brings three figures into sharper focus, provides insightful readings and translations of substantial primary texts, and ensures that neither figures nor their texts can any longer be ignored in accounts of the fourth/tenth-century philosophical landscape.
