The most common explanation for the common link’s failure to provide consistently accurate and reliable dating of early Islamic traditions involves the so-called spread of isnāds during the process of transmission.45 As Schacht first recognized, it is altogether likely that these authoritative chains of transmission were altered by the complications of transmission over an extended period of time as well as by the editorial interests of an evolving Islamic tradition. The result is that many isnāds are contaminated and do not preserve an accurate record of historical transmission, particularly in the earliest stages of this process. According to Schacht, the “spread of isnāds” involves “the creation of additional authorities or transmitters for the same doctrine or tradition.” This phenomenon is particularly evident in material ascribed to Successors of the Prophet, and it can often create the illusion that the common link, and thus the tradition itself, circulated earlier than it actually did.46
Nevertheless, Motzki and others advocating the reliability of this method have largely rejected out of hand such concerns about any significant spread of isnāds, inasmuch as their approach demands accurate records of transmission. As these scholars seek to mine ever deeper within these transmission histories in hopes of securing traditions even closer to the beginnings of Islam, a much more optimistic view concerning the reliability of these textual genealogies is required, particularly in regard to the early transmitters. While occasionally this approach has convincingly dated certain traditions to the beginnings of the second Islamic century, Motzki often argues aggressively for an even earlier dating, to the first Islamic century. Yet in doing so he generally must engage in special pleading on behalf of early tradents,47 and as several critics have noted, these efforts to push certain traditions into the seventh century are methodologically problematic and not very convincing.48 Motzki seeks to further enhance these claims of authenticity by raising the stakes and forcing a decision between either accuracy and genuineness or outright forgery and vast conspiracy. If the reliability of these pedigrees is to be doubted, then one must suppose the existence of a widespread and deliberate conspiracy of forgery within the early Islamic community on a scale that is historically improbable.49 The rhetorical effect of this position is effectively to shift the burden of proof, requiring any skeptics to account for what is reckoned to be the only alternative to “authenticity,” a grand conspiracy of forgery.
These are not, however, the only two possibilities, as many less sanguine scholars have remarked, and generally one would not want to insist on such a severe bifurcation in analyzing the formative period of a religious tradition.50 G. R. Hawting, for instance, has critiqued this falsely posed either/or well in his review of Motzki’s book, the full extent of which is worth quoting:
It seems unlikely that this stark contrast is an adequate view of what is a religious tradition, produced during a relatively long period of social and political disruption when the institutions for safeguarding the transmission were only beginning to be formed, subject to the vicissitudes of a still mainly oral culture, and committed to writing in the form in which we have it at the beginning of the third century of Islam at the earliest. Motzki seems to have little time for the effects of the continuous reworking of the tradition, the introduction of glosses and improvements, the abbreviation and expansion of material, the linking together of reports which originated independently, the adaptation of traditions which originate in one context with a particular purpose so that they may be used in another, let alone simple errors of scribes and narrators. One cannot rule out real forgery but what that might be in a society which revered authority and tradition above independence and innovation is not obvious. Students of the historical tradition (taʾrīkh) have been able to demonstrate the way in which the tradition could be manipulated to give significantly different messages even after it had been recorded in writing (cf., for example, the way in which al-Ṭabarī was used by the later compilers like Ibn al-Athīr). This sort of creative reinterpretation must have been much more possible in the stages before the appearance of written texts.51
One can in fact identify a variety of interests and tendencies within the early Islamic tradition, as well as certain features of the process of transmission itself, that may have effected the manipulation of isnāds. Michael Cook presents perhaps the most detailed explanation of this phenomenon, and he describes numerous mechanisms by which isnāds likely spread, none of which, it is important to note, involves a grand (or even modest) conspiracy of forgery. On the contrary, Cook identifies several very ordinary events from the process of transmission that likely have introduced the spread of isnāds, and all of these are “thoroughly in accordance with the character and values of the system [of transmission].”52 Patricia Crone additionally explains how the rivalries between various centers of early Islamic scholarship (that is, Medina, Mecca, Kūfa, Baṣra, Syria) likely brought about the spread of isnāds in many instances.53 Likewise, Norman Calder’s study of the early Islamic legal tradition identifies still more factors that likely influenced the process of transmission and caused the spread of isnāds. Calder focuses particularly on doctrinal differences as a vector for such changes, and he presents a compelling example from the ḥadīth that clearly evidences the spread of isnāds occasioned by inter-Islamic dogmatic disputes.54 Any one or a combination of these factors could easily have inspired adjustments to these records of transmission, introducing distortions that would lead to the identification of false common links and, by consequence, inaccurate datings.55 Thus, while the use of common-link analysis to date material may be accepted somewhat provisionally, one must always bear in mind the failures of this method when it has been tested and the potentially deviating effect of the spread of isnāds.56 In order to guard against such inaccuracies, this approach can be applied effectively only to traditions bearing an extremely dense pattern of transmission from multiple, intermediate common links, a threshold that few traditions prove capable of meeting. Moreover, while this approach has shown some success in locating a number of traditions at the beginnings of the second Islamic century, for many of the reasons noted above, it has not proven very effective for identifying traditions from the first century with much credibility.57
Despite these problems, a small group of scholars has recently applied this method to a selection of sīra traditions, not in an effort to recover early traditions from much later sources, where it may perhaps prove effective, but instead with the intent of securing elements of Muhammad’s biography to figures from the first Islamic century. In particular, they have aimed at exhuming a core of tradition that can be assigned to ʿUrwa ibn al-Zubayr’s authorship, thus fixing the outline of Muhammad’s career to this scholar from the end of the seventh century and the beginning of the eighth. In this way they would attempt to establish the historical accuracy and authenticity of at least some of the basic events from the traditional narrative of Islamic origins. At issue is the general reliability of the early sīra traditions for knowledge of Muhammad’s life and the beginnings of Islam: the historical veracity of these accounts stands very much in question. As already noted, the narrative traditions of Muhammad’s life were rather late in forming, and even the earliest sources, such as they are, can be known only indirectly through more recent transmissions. Accordingly, one must reckon with the fact that during the century that elapsed between the end of Muhammad’s life and the first recoverable narratives of Islamic origins, the Islamic faith almost certainly underwent significant changes in its beliefs and practices. As the chapters to follow will argue, Islam’s transformation during this first century seems in fact to have been considerable, involving the shift from an imminent eschatological belief focused on Jerusalem to become the religion of a global empire with a sacred geography centered on the Hijāz. Such developments were bound to have an effect on Islam’s self-image,