Alexander Orwin deserves our gratitude for writing a most lucid account of al-Farabi's (ca. 870-950) conception of the umma, the Muslim community or nation, taking into account the extensive historiographical debates on the subject.
Redefining the Muslim Community: Ethnicity, Religion and Politics in the Thought of Alfarabi is well-written and cogently argued. The author presents the ninth-century philosopher's thought in modern political idiom (without losing sight of the obvious pitfalls of anachronistic presentism), thereby offering his reader the opportunity not just to learn about al-Farabi, but also to grasp the continued relevance of this towering figure of medieval philosophy known as tthe "Second Master," Aristotle being the first. Orwin has judiciously chosen to go beyond his subject's role as a transmitter of Greek thought, to make the case for "a more Muslim-oriented approach to his teachings," one that is "especially suited to both Alfarabi's concerns and our own," and finally, to demonstrate that he is "much more attuned to worldly affairs than many people think" (11). Al-Farabi lived amidst Zoroastrians, Jews, and Christians; to him the urgency of establishing best rule over a multiplicity of nations was of a wholly different order.
Orwin sets the stage with his prolegomena, on the thorny problem of studying a conception of "nation" before the advent of modern nationalism; the life of al-Farabi; the reception of his ideas; the ebb and flow of interest in al-Farabi's works; his writing style; the critical literature on al-Farabi; and the importance of studying al-Farabi as a Muslim philosopher rather than an uncritical transmitter of Greek thought. Hellenistic source-hunting forays, which tend to dominate much of the scholarship on al-Farabi's political thought, can lead to an impasse, in Orwin's view, for even the most authoritative researchers have often reached "the riveting conclusion that nothing can be determined" (11). For example, we still seem unable to recover the contents of al-Farabi's Greek library, although Orwin holds that the philosopher must have had access to something resembling the original texts of the Republic, and probably several other Platonic dialogues (17). Not so in the case of Aristotle's Politics, which he never cites (36-38).
Chapter 1 is a careful close reading of the meaning and function of the city and the Umma in al-Farabi's reconstruction of Aristotle and Plato as we have it in his Philosophy of Plato and Aristotle,  juxtaposed with corresponding sections in the Republic and Politics. Orwin shows that a sense of community tied to language and ancestral custom and fostered over generations is substantively more integral to al-Farabi's reconstruction of Plato, and more still to his own work, than to the Greek philosopher. And while Aristotle privileges the city vis-à-vis the nation in Politics, and both Plato and Aristotle see the nation as a major obstacle to the realization of the best city and regime (43), no such claim is found in al-Farabi's work.
In chapter 2, Orwin turns to al-Farabi's definition of the Umma in a wider variety of his work. Ummas are differentiated one from the other by natural causes: different climates allow for different kinds of plants and animals to thrive in different regions, and those regional variations have their effects on the humans that consume them, hence "a habitable world divided into Ummas, each of which occupies a particular spot on the earth's surface and possesses a fixed and inalienable character" (46). Those differences are further inflected by the mainly conventional trait of language, which is an altogether more dynamic and more consequential inheritance than climate and nutrition. Notably, al-Farabi makes no "connection between religion and the Umma" (51), but studies in great length the literature, art and culture that is cultivated among different nations--that is, among different language-born communities. On moral and physical causes for differences among nations, Orwin points to the similarities between al-Farabi and David Hume (51-52). For immediate context, Orwin places al-Farabi in conversation with his near contemporaries, al-Jahiz (d. 869) and al-Tawhidi (d. after 1009), to conclude--rather anachronistically--that none harbored "national stereotyping" or "favored polemics among Ummas" (64). More on that point below.
The next chapter investigates al-Farabi's conceptualization scheme. Orwin proposes to scrutinize the particular relationship that the medieval political theorist laid down between the Umma and philosophy, all the more interesting because he ignores the subjects of religion and politics. Al-Farabi explains the superiority of philosophy over the Umma thus: "While the Umma is particular, philosophy is universal" (67). The science of linguistics, which corrects the errors in the speech of a particular Umma, likewise varies from one Umma to the other. Logic, which serves as a scrutinizing check on philosophical inquiry is, however, constant in various Ummas. "Philosophy itself, although first defined in the Greek language, passes seamlessly from Umma to Umma without losing its status as the highest art, the highest virtue, and the highest wisdom" (67).
Chapters 4 and 5 are devoted to the other kind of Umma, the specifically Islamic Umma that is defined not as a civilization delineated primarily by common language and literature, as al-Farabi would have it, but by the Quran and contingencies of history. Orwin notes the dual significance of the Umma in Islamic history: "the ethnic nation and the Islamic religion" (87). Against prevalent scholarship that maintains a deliberate silence on the part of al-Farabi regarding the religious Umma, Orwin sets out to demonstrate that the philosopher alludes to the Muslim Umma albeit "in a subtle but highly revealing manner" (87). In contrast to the jurists and theologians, al-Farabi's account of the origin of religion is not based on Muhammad, his Companions, and his traditions (collectively known as ahadith. It entails development over time and hardship, as the community lived through unending conflict and sweeping change. Since multiple accounts of those developments exist, "the original intention of the lawgiver, whatever it may have been, has become irretrievable" (111), and it is impossible to recover the events themselves. But al-Farabi does not dispense with the jurists altogether: rather, he aims to challenge their glorification of the past without diminishing their authority. Furthermore, his virtuous Umma transcends ethnic difference to become unitary, and to "benefit the other cities and Ummas, bringing them to happiness in this world and the next" (115).
The remaining chapters focus on al-Farabi's prescription for practical politics, or how the Umma engages with tribe, city, and empire. In chapter 6, Orwin sketches al-Farabi's desideratum: a virtuous Umma that will cultivate political prudence, artistic creativity, and philosophical inquiry (205), and teach the ignorant cities and the religious authorities who may listen to them to avoid conflict, to accommodate difference, and to "become voices of political compromise and cultural enrichment rather than war and jihad" (173), if not yet fully-fledged toleration. Al-Farabi's discussion of various types of regimes, including the democratic city, is taken up in chapter 7, which also includes a brief survey of how various later thinkers, European as well as those from the Islamic world, engaged with al-Farabi's political thought, or might have benefited had they done so. From modern Islamic thinkers, the chapter chooses al-Afghani (d. 1897) and Muhammad Iqbal (d. 1938). Modern resonances of al-Farabi's Umma contra ethnic nationalism are further developed in the Conclusion.
Orwin's study is rich and rewarding, although medievalists may be taken aback by his claim that in the annals of the history of political thought prior to Rousseau, al-Farabi alone displayed interest in the concept of the nation (1, 3-4). Admittedly, the question of premodern nationalism is a longstanding dispute between historians and political theorists. The pre-nationalist nation, defined by ethnic and/or linguistic ties of unequal verisimilitude, engaged, to take one example, a substantive chunk of early historical writing produced in Merovingian and Carolingian Francia, as Helmut Reimitz has shown.  And an exploration of the comparative frame developed by another of al-Farabi's near contemporaries, the celebrated Biruni (d. 1048) to study various nations (marked by religion in this instance) would have been instructive.  Had Orwin adopted a medievalist's lens, and settled on ethnogenesis rather than the pre-nationalist nation, the singularity of al-Farabi's take on the Umma may have become less defensible, with the added bonus that he would see the apparent ethnogenesis in the debate between the Christian logician Abu Bishr Matta (d. 940) and the Muslim grammarian Abu Sa'id al-Sirafi (d. 979), recorded by al-Tawhidi (69-70) as "a code that must be deciphered in order to grasp the process of social change," as Patrick Geary and others have done.  That approach might also have yielded a more lucid explanation of why al-Farabi readily attributed philosophy to the Greeks and characterized it as a foreign import among Arabs, but declined to designate Aristotle and Plato as Greek in specific instances, while doing so willingly in others (68).
1. Alfarabi, Philosophy of Plato and Aristotle, trans. Muhsin Mahdi (New York: The Free Press of Glencoe, 1962).
2. Helmut Reimitz, History, Frankish Identity and the Framing of Western Ethnicity, 550-850 (Cambridge: Cambridge University Press, 2015).
3. On Biruni, see Mario Kozah, The Birth of Indology as an Islamic Science: Al-Biruni's Treatise on Yoga Psychology (Brill: Leiden, 2016).
4. Patrick Geary, "Ethnic Identity as a Situational Construct in the Early Middle Ages," Mitteilungen der anthropologischen Gesellschaft in Wien 113 (1983), 15-26; and to bring but one example from medieval Islamic studies, James Montgomery, Al-Jahiz: In Praise of Books (Edinburgh: Edinburgh University Press, 2013).