1 — Legal Science and Its Roots

Al‑Juwaynī introduces his Leaflet on the Sources of Law diminutively as “a few pages,” yet their scope is broad: all the major topics of legal theory (uṣūl al‑fiqh, literally “the sources of legal science”). He does not promise to be comprehensive, and indeed he omits a number of significant subsidiary topics, which I will point out in passing; but he includes all the major subjects that are covered in comprehensive legal theory treatises such as his own monumental work al‑Burhān. In Chapters 1–4 he gives some preliminary definitions. In Chapters 5–10 he describes the raw material of revelation, covering its linguistic and historical features. In Chapters 11–16 he describes several ways for interpreters to resolve contradictions and fill in gaps in revelation: consensus, analogy, the transmission of Prophetic reports, and how to reconcile or choose between conflicting pieces of evidence. In chapters 17–18 he steps back to reflect on the role of the human interpreter (mujtahid).

Law as a tree or a building

He begins by defining the relationship between the sources of law (principally revelation) and law itself (fiqh, legal science). What exactly does it mean for revelation to be the “source” of law? This English term suggests that law “comes from” revelation, as water pours forth from a spring; but al‑Juwaynī’s own definitions of aṣl (source, root, or foundation) and farʿ (branch) suggest two quite different answers: either law grows organically like a tree from revealed roots, or law is constructed like a building upon a foundation of revealed texts.

On the one hand, the very fact that al‑Juwaynī chooses to contrast aṣl with farʿ (a term he could have omitted altogether) shows that he wants us to picture law as a tree whose roots are the Qurʾān and Sunna, and whose branches are the detailed answers to specific legal questions that constitute legal science. The rules are called branches because they subdivide and branch off to address numerous subquestions and special circumstances. This is a common way of imagining the law; some legal theorists even refer to the process of interpreting revelation as istithmār, which literally means “making it bear fruit.” This horticultural metaphor suggests that every little detail of the law is fully determined by revelation, just as the shape of every leaf on a tree is already encoded in the roots from which it grows. Diligent inquiry, in this picture, is like the work of a gardener, who merely provides the environment that is needed for the unfolding of a plant’s DNA. Human thought and culture provide the environment to which the law adapts itself, but they can no more determine its content than a gardener can choose to grow oranges on a persimmon tree.

On the other hand, al‑Juwaynī’s actual definitions of aṣl and farʿ contradict this organic metaphor. Others have defined source as “whatever something else comes from,” “whatever something else gets its substance from,” or simply “that from which other things branch off.” Any of these definitions would reinforce the idea conveyed by the tree metaphor, that the content of law stems entirely from revelation. Instead, al‑Juwaynī chooses to define root as “that on which something else is built.” This evokes the image of a foundation (revelation) upon which a building (legal science) is erected. He even defines farʿ as “that which is built on something else,” even though farʿ normally means branch, not building. This definition makes legal science a human construct, and implies that diligent inquiry may involve much more than just teasing out the implicit meaning of revelation. It suggests that while revelation may dictate the building’s footprint, human thought and culture may make a material contribution to the edifice of legal science. Of course, al‑Juwaynī means building in an abstract rather than a concrete sense, so perhaps he does not mean to imply all that the image of a builder suggests. But if our word choices convey something about how we think, and even shape how we think, then it is significant that although al‑Juwaynī echoes the tree metaphor, and thus implies that law stems entirely from revelation, he explicitly and quite literally defines law as a human construct. To restate this in terms of the hermeneutical debate over who controls the meanings of texts, so far al‑Juwaynī has emphasized the reader’s role in constructing the legal meaning of revealed texts, while still claiming implicitly that their meaning stems solely from the texts themselves. He has not yet said what role their divine author might have in determining their meaning.

The uncertainty of legal science

Al‑Juwaynī’s focus on the reader’s contribution to meaning is reinforced by the way he defines legal science (fiqh). Notice that not all knowledge of the law constitutes legal science. The common person’s knowledge that prayer is obligatory and fornication forbidden does not count as legal science; that term is reserved for knowledge of those details that can only be figured out by scholars through diligent inquiry. As will become clear below, a scholar never knows for sure whether the result of his diligent inquiry is correct, so “legal science” is always uncertain, and may turn out to be incorrect belief rather than true knowledge. Only God really knows every detail of his law, the sharīʿa; legal science (fiqh) is just an uncertain and very human attempt to reproduce the sharīʿa as closely as the sources and the methods of diligent inquiry permit. By defining legal science as the product of diligent inquiry, al‑Juwaynī has placed it entirely within the domain of human uncertainty. The foundations are of divine origin, but the legal science that is built upon them is entirely a fallible human construct.

Not all definitions of legal science make it so uncertain. In his Burhān al‑Juwaynī himself says explicitly that mere belief does not constitute legal science, and this leads him to define the “sources of legal science” as only those indicators that give epistemological certainty: the Qurʾān, those few reports about the Prophet’s Sunna that are unquestionably authentic, and consensus. This gets him in trouble, since most of Islamic law is based on more doubtful evidence such as analogies or reports that might possibly be incorrect. He wiggles out of that bind by arguing that while many details of the law are uncertain, we know without a doubt that we must follow them anyway, and it is that knowledge that he calls legal science. His concern in the Burhān is to distinguish certainty from mere belief, and to insist that the uncertainty of diligent inquiry does not undermine the certainty of a Muslim’s duty to obey. Here in the Waraqāt his goal is simply to describe diligent inquiry, which he recognizes as a fallible human construct.

Another famous definition of legal science was advanced by Abū al‑Ḥasan al‑Ashʿarī (d. 935), after whom is named the Ashʿarī theological school to which al‑Juwaynī belongs. Rather than defining legal science as the knowledge of law that one gains from interpreting revelation, he defined it as the understanding of revelation as it relates to law.⁹ The difference is subtle but important: legal science is not knowing something about human actions, it is understanding the speech of a person, God. This implies that the legal meaning of revealed texts is determined by their author, and that the human interpreter has achieved legal science only insofar as he has grasped God’s intent. Al‑Juwaynī’s definition of legal science has the opposite effect of making meaning a product of the interpreter.

Ways of imagining Islamic law

Al‑Juwaynī undoubtedly knew of many ways to define “roots” and “legal science,” but for this introductory book, which would shape how Islamic law was imagined by some twenty generations of students in several Sunnī schools of law, he chose definitions that made the law a divine and human joint venture, springing from divine revelation yet built by fallible human interpretation. This leaves us with a hermeneutical question to ask as we proceed through the remainder of the treatise: who controls the legal meaning of revealed texts? Is it God, the ultimate author of revelation? Or, if he is absent from the interpretive process, do the texts themselves contain encoded within them a comprehensive law that reveals itself through the process of diligent inquiry, as a tree branches out and produces its genetically determined fruit under the care of a gardener? Or, as al-Juwaynī’s definitions emphasize, is it the jurist himself who constructs the law like a builder, adding human intuitions about what is just and fair on top of the moral foundation laid down in revelation?

This is not just a question of organic versus architectural metaphors; it is a question of the very nature of Islamic law. It is important to realize that while al‑Juwaynī’s way of imagining the law is fairly representative of many Sunnī jurists since the 11th century, it is by no means the only way in which Muslims have envisioned the law. Early in Islamic history it was not at all obvious whether law should be distinctly Islamic at all, or whether it should be just a continuation of preislamic laws, modified as needed by rulers and their appointed judges to suit changing needs and values, just as preislamic laws had been retained and modified by the Prophet to suit his circumstances. If law was to be distinctly Islamic, what was to make it so—the fact that it was followed by early Muslims (as emphasized by some early jurists), the fact that it was sanctioned by living religious leaders (as per the Shīʿa), or the belief that it had been revealed through the Prophet? If the latter, where was that revelation to be found—in the Qurʾān alone (as per the Khārijiyya and some Muʿtazila), or also in reports about the Sunna of the Prophet (as per al‑Shāfiʿī)? And did those texts themselves constitute a sufficient law, directly applicable to every concrete situation (as per many early traditionists, Ḥanbaliyya, and Ẓāhiriyya), or was there a need for a comprehensive system of rules apart from revealed texts (as per al‑Shāfiʿī and many other jurists)? If the latter, how was that law communicated through revelation—was it brought about by and immediately understood from the very language of revelation (as per the Ḥanbalī theorists Abū Yaʿlā and Ibn Taymiyya), or did it have to be deduced from the words of revelation through a careful process of rational inference (as per Muʿtazilī and Ashʿarī theologians)? If the latter, was the language of revelation clear and lucid, permitting confident and straightforward interpretation (as per the Muʿtazilī ʿAbd al‑Jabbār), or was it murky and ambiguous, requiring frequent hesitation and complex interpretive maneuvers (as per al‑Juwaynī’s great Ashʿarī forebear al‑Bāqillānī)?

Al‑Juwaynī chose one side in each of these debates: law should be distinctly Islamic by virtue of having been revealed through the Prophet in the form of both Qurʾān and Sunna; and it should be developed as a comprehensive body of rules, distinct from revelation but deduced from it through a careful but fallible human interpretive process that takes account of the many ambiguities of revealed language. But there were many possible combinations of answers to these questions, and hence at least that many different ways of imagining the law, and probably many more—perhaps even some that no Muslim has ever thought of.

Further reading

On various ways of imagining how God reveals law, see David Vishanoff, The Formation of Islamic Hermeneutics: How Sunni Legal Theorists Imagined a Revealed Law (New Haven, Connecticut: American Oriental Society, 2011).