It has been refuted. The guy in the video is named Robert Spencer, he wrote a book on this topic. A catholic Christian, very likely a closet islamophobe in light of his other books, which were most certainly not hastily written but slowly with biased calculation (as per this one).
His book on the topic can be seen here:https://www.amazon.co.uk/gp/aw/d/1610171330/ref=mp_s_a_1_1?ie=UTF8&qid=1469211372&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=did+mohammed+exist
This is the refutation, it is certainly an interesting read and sheds light on the deception of Christian missionaries. The person who refuted it is amazon user Yasin100 (can be found in the reviews in that link), here is the full refutation:
Notwithstanding a sizable section on the Qur'an, the principal objective of this book is to show that the Islamic Prophet Muhammad is a historical myth, a person who most probably never existed. The book is quite bold then, proposing a thesis has never been proposed. But has Spencer provided a convincing argument? Has he unearthed a grand forgery which, for 1400 years, has managed to fool countless scholars and believers? One would think so from the numerous 5 star reviews. I for one think not! I think that, much like the Jesus mythicist literature, the book is ultimately unpersuasive. Let me give a few reasons.
[1] One of the most immediate problems one encounters is Spencer's subjective use of scholarly material and a flick through his bibliography illustrates his heavy handed bias for revisionism. Since no reputable academic scholar, mainstream or sceptic, holds to the non-existence of Muhammad, Spencer is forced to rely on an obscure ultra-revisionist fringe, some of whom are scholars whose works are largely marginal or dated, and some others who are evidently not scholars at all. In his introduction, Spencer lists the scholars whose work he researched, classifying them as "earlier generation" and "modern-day" scholars. Regarding the earlier generation, Spencer uses their material craftily pouncing on any area of the Islamic literary tradition they doubted while ignoring their overall assessment of the sources. Thus Goldziher's suspicion of some political and theological traditions is transformed to a suspicion of all traditions. Schacht scepticism regarding legal traditions is transformed to scepticism of everything. What Spencer fails to mention to his readers is that many of these `earlier generation' of scholars were in actual fact known for their biographies of Muhammad. Spencer utilizes some of David Margoliouth's arguments, but fails to tell his readers about, or include in his bibliography, the 550 page biography of Muhammad written by Margoliouth entitled "Muhammad and the Rise of Islam". Similarly, Spencer utilizes the arguments of Aloys Sprenger without mentioning, or noting in his bibliography, that Sprenger authored a 220 page biography of Muhammad entitled "The Life of Muhammad from Original Sources". He utilizes a few of William Muir's points without mentioning that Muir wrote a massive 4 volume biography of Muhammad entitled "The Life of Mahomet". Thus one has to question Spencer usage of these scholars when they wrote so extensively about the Muhammad.
Spencer's use of `modern-day' scholars fairs no better. He ignores mainstream scholarship for a fringe group of ineffectual revisionists. Even when quoting recognized sceptical scholars, he ignores their most recent works for dated ones. For instance, on page 13 Spencer writes that he relied on "Crone's earlier work". Why Crone's earlier work? Why not her current and latest works? The answer is simple. Crone's current work is rather mainstream. In fact Crone and Cook have either renounced or revised their revisionist theses of the 1970's and 1980's which Spencer is so heavily reliant on. All one has to do to know this is read anything Crone or Cook have written since 2000. Spencer evidently laments this fact but he is unwilling to let such exciting and salacious theses go. He writes on page 13 that Crone's writing on Muhammad in 2008, where she emphatically states the historicity of Muhammad, "represented a departure from her earlier position on Islam's origins". However, he justifies his grip on her renounced thesis with the hollow words: "she offers no new findings or evidence to explain the change; instead she left her earlier reasoning and the evidence presented standing untouched". What could be weaker than to hold on to a thesis that has been rejected by both the entire scholarly community and Crone herself? Why doesn't he read her current works where she does indeed offers her new findings and evidences along with the findings of other academic scholars such as Mikhail Bukharin, Peter Stein, Jan Retso, Isabel Toral-Niehoff, etc?
In addition to his slanted handling of scholarly material, a careful read of Spencer book arouses suspicion as to whether is has even read any of the works he claimed to have research. The works of Author Jeffrey, Henri Lammens, Alphonse Mingana, Theodor Noldeke, Alloys Sprenger, Julius Wellhausen, and Sulaiman Bushear-the scholars he listed in the introduction to have research- do not appear in the bibliography. Secondly, when mentioned, these scholars are never cited directly from original works. Spencer's references to Gustav Weil, Ernest Renan, and William Muir are also taken from Ibn Warraq's book, not the original work. His references of Muslim scholars Al-Jahiz, Ad-Darimi, Abu Dawud, An-Nasa'i, Al-Qastellani, Ibn Majah, Al-Yaqubi, Al-Baghdadi, and Ibn Hajar al-Asqalani are all taken from Ignaz Goldziher's book, not the original works. Thus Spencer's book is replete with the coping-and-pasting of other people's citations. To makes matter worse, Spencer also has the habit of citing works without giving a full reference so it can be checked. The more astute readers will not be surprised if in the end Spencer's book is really nothing more than a rehashing of the popular arguments raised in the books of Warraq, Puin, Luxemburg, Nevo, and Luling with every other citation used to make to book appear more scholarly. Ultimately, when Spencer says on page 9 that "this book is the fruit of my research into the writings of scholars of earlier generations....as well as modern-day scholars", we have to take it with a pinch of salt.
[2] Another problem one encounters is Spencer's pivotal assumption which is crucial to the validity of his whole argument. His thesis assumes that as the early Arab-Muslims conquered the vast territories of the Byzantine and Persian Empires, they would have made an instant top-down (A-Z) transformation of the whole North Africa and Near & Middle East. That is to say, the Arab-Muslims would have instantly started minting their own coins, constructing architectural monuments, transforming administrative practises, altering trade patterns, modify agricultural norms, changed the administrative language to Arabic, and so forth. In doing so, they would have left ample archaeological evidence for their religious beliefs. It is only by constructing a grand "this is what we would expect if..." assumption, which builds up our expectation, that he can then justify his en-silencio thesis when the evidence doesn't live up to the unrealistic expectation.
Those acquainted with scholarship in the field appreciate however that until the second fitnah, which saw Umayyad Caliph Abdul' Malik ibn Marwan rise to power in 685 CE, the Arab-Muslims conquerors had a rather light footprint. At least three things contributed to the early obscurity of the Arab-Muslims. Firstly, the Arab-Muslims lived in garrisons towns such as Homs and Kufa on the outskirts of the urban centres and were uninterested in mingling with the general populous. Secondly, there lack of material expertise precluded their proclamation of their religion in media such as coins or architecture. Thirdly, the earliest period of Islam saw major internal upheavals which precluded the development of a stable bureaucratic state/empire. The Muslims were themselves engaged in theological and political upheavals which meant that much of the early Arab-Muslims energy and resources went towards internal resolutions instead of outward propagation. These three reasons, among others, delayed the public expression of Islam for the first fifty years. The events leading to `Abd al-Malik's Caliphate would mark the first ostensible attempts of Muslims to proclaim their religion Abdullah ibn Zubayr's challenge to the caliphate, the kharaji rebellion, and `Abd al-Malik's success to leaderships brought a lot of changes. His reign marked a number of significant changes including the minting of fully Islamic coins, the formation of a professional standing army, Arabic as the lingua franca, the centralization taxes and modified trade routes. Following AD 685, virtually all coins, papyri, tombstones, seals, and most architectural monuments have overt Islamic references. The best documentary witness to this slow gradual transformation is in the coinage. The earliest Islamic coins were cheap Byzantine and Sasanian prototypes. The iconography remained the same. The only way you would know it was an Islamic coin was the inscribing of `bismillah', `jayyid', `ja'iz', `dayyib' or some other small Arabic inscription. Other times, this inscription will be accompanied the removal of the cross. This process continued until the time of Abdul Malik when the Arab-Muslims developed one centralized administration to mint their own coins. The final Islamic stage of coinage was epigraphic coins with Qur'anic calligraphy and, of course, no imagery. This was a gradual process with many bumps along the way.
Spencer wants us to assume the overly simplistic, even comical, view that the Arab-Muslims would have burst into the scene "shouting `Allahu Akbar, invoking Muhammad, and quoting the Qur'an" (p. 63). In doing so, they would have presumably stunned the Byzantine and Sasanian populous who would have started writing about it immediately in detail. Once the expectation is of an epochal transformation and the evidence shows a more humble gradual change, the conclusion reached is that Islam was not there, Muhammad didn't exist, and everything is a lie. This is the flawed assumption that provides the main premise of this thesis. One can apply such reasoning to Spencer's own faith. Let's make a parallel assumption. If, as the New Testament tells us, St. Paul and the earliest Christians really travelled from city to city in the Mediterranean proselytizing their faith, we should expect to find some reference to them in non-Christian works. Furthermore, if they were really singled out in punishment, we would expect to find some official reference. Yet, in a well literate world with many contemporary historians, not a single non-Christian text mentions Jesus, Paul or the earliest Christians until Josephus in AD 95. Furthermore, not a single piece of documentary evidence exists for Christianity in the first century. If the story was true we would expect to find non-Christians referring to this new religion, but they don't. Furthermore, they left no material traces of their faith and none of their texts are attested in the first century. Here I have constructed a parallel argument, quite similar to those made in Jesus mythicist literature. Would that convince catholic Spencer or a professional historian? I think not. To ignore the fact that Christianity until the time of Constantine was the religion of a persecuted minority which could not really assert its claim in architecture and coinage would be disingenuous. Likewise, to ignore all the factors that delayed the explicit public expression of Islam in the material culture for the first 50 years is equally disingenuous.
[3] A third problem is the inadequacies of Spencer's methodology. For example, he is frequently inconsistent and incoherent. As for inconsistency, readers will encounter Spencer rubbishing a source because it is late. You will then surprisingly find that he uses late, sometimes very late, material when it supports his thesis. There are several instances of this. One especially notable case is found in chapter 2, page 59, where Spencer argues that the Qur'an postdates Caliph Abd al-Malik. To argue this, Spencer adduces as evidence a tradition found in the work of 16th century traditionalist al-Suyuti (d. 1505 CE). Spencer remarks that "it is hard to explain why this hadith would have been invented at such a late date unless it contained some kernel of authenticity". Thus while Spencer adopts the revisionist criteria of history, he has no qualms utilising literary material 900 years after the fact as long as it supports his argument.
As for his incoherence, an example includes Spencer's adoption of very simplistic black or white view on everything. We see it when he dismisses something being Islamic without exploring all the possible interpretations. He simply adopts the interpretation most conducive to his thesis. For example, Spencer will deny that coins with iconography are Islamic. Why? Because orthodox Islam forbids pictures of animate creatures. However, did all Muslims regard pictures-making as impermissible? Did every single Muslim know the impermissibility? Did every single Muslim abstain from it? These possibilities are never explored. It's black or white. A student of Islamic Art & Archaeology will read such arguments with laughter. All one has to do to refute this is to explore the first century Umayyad desert palaces replete with pictures of people, animals, celestial bodies, along with all those post-reform coins which continue to have pictures despite carrying the Islamic testification of faith. How can the first century coin containing the Islamic testification of faith, Islamic dating system, and two verses of the Qur'an be un-Islamic because it also happens to contain the picture of the Caliph in the obverse? Spencer would relegate the coins on the basis of the picture only by ignore all the Islamic inscriptions the surround the picture.
Another example of dubious methodology is Spencer's constantly assumptions about what Muslims would have done. When he looks the Qur'anic inscriptions on the Dome of the Rock for instance, he argues that if Muslim wanted to say A, they would have cited the Qur'anic passage B. If they wanted to say C, they would have cited D. If they wanted to say E, they would have cited F, etc. Why doesn't he simply look at what they actually cited instead of looking at what they may have? How does he know what the intensions of the inscribers were? A very sound methodology indeed!
[4] Hitherto I have concentrate on Spencer's use of scholarship, his patently fallacious assumption, and the shortcomings in his methodology. Now I will look at his handling of the evidence. As far as sources for Muhammad from the first century go, there are three types: Muslim literary, non-Muslim literary, and documentary sources. As for Islamic texts, they include the Qur'an, the constitution of medina, the sahifa of Hamam ibn Munabih and the sahifa of Abdullah ibn `Aas. Three of these texts are contemporary with Muhammad and the other derives from a contemporary. As far as non-Muslim texts are concerned, there are at least 14 non-Muslim texts mentioning Muhammad within 100 years of his death, 8 are within 60 years, 5 within 30 years, 3 within 10 years, and 1 within 2 years. Contrast this with the earliest non-Christian reference to Jesus which comes 65 years after Jesus in the writing of Josephus. The earliest non-Muslim reference to Muhammad is 2 years while the earliest non-Christian reference to Jesus is 65 years. For any sensible historian, these non-Muslim texts constitute impeccable evidence for Muhammad. This is why in 2008 Patricia Crone, whom Spencer relied for her `earlier works', says that "(t)here is no doubt that Mohammed existed, occasional attempts to deny it notwithstanding. His neighbours in Byzantine Syria got to here of him within two years of his death at the latest......The evidence that a prophet was active among the Arabs in the early decades of the 7th century, on the eve of the Arab conquest of the middle east, must be said to be exceptionally good....But in any case, this source gives us pretty irrefutable evidence that he was a historical figure". Such textual sources which provide, in Crones words, `irrefutable evidence' cannot be left standing if Spencer is to argue for his thesis. But how does he go about doing do so?
As far as the non-Muslim texts are concerned, Spencer employs a number of strategies to rubbish them from omitting them (i.e. the Syriac Gospel Fragment dating 637 CE, just 5 years after Muhammad death at 632 CE), picking away at every little nitty-gritty detail they get wrong and using that as a basis for their total unreliability, commenting on every part that contradicts Islamic traditions, cites irrelevant texts, challenging scholarly translations even though he doesn't know the language himself, and hypothesizes that some of these references could be referring to other than Muhammad without, of course, telling us who exactly these other people are. In other words, Spencer adopts any reason to rubbish these texts, however silly. He doesn't, even for a moment, explore the cumulative weight of these texts. These texts were written by several different religious communities, in several different languages, geographically situated thousands of miles away from each other. How could they all mention an Arabian monotheist prophet Muhammad? There are three possibilities. Either it's true that that a person called Muhammad actually existed, it could be a grand conspiracy for reasons beyond us, or its just one monumental fluke. I have no trouble assessing which is most plausible.
[5] His handling of the documentary material for Muhammad is perhaps even worse. Within fifty years after Muhammad's death, we have Muslim coins, papyri carrying the Islamic dating system, inscriptions which make mention of Muhammad companions such as Umar Ibn Khattab and Mu'awiyaa ibn Sufyan, tombstones, dams, milestones, Qur'anic manuscripts, and even textiles. Admittedly none of them mention Muhammad, but they do constitute documentary evidence for early Islam. Again, contrast this with Christianity which cannot adduce even a single documentary source until John Rayland Library Papyrus P52 dating 130CE. The earliest Islamic documentary source is 8 years after Muhammad while the earliest Christian documentary source is 100 years after Jesus. The first clear documentary reference to Muhammad occurs in the Zubayrid drahma, dated 685 CE, 53 years after Muhammad, which has inscribed "Muhammad is the Messenger of Allah".
How does Spencer deal with the dated documentary sources mentioning Muhammad? Here cannot dispute their existence. He cannot dispute their dating. He cannot dispute their provenance. The only thing left is linguistic gymnastics and omission. As for linguistic gymnastics, Spencer argues that Muhammad in these documentary sources does not refer to the prophet Muhammad, but refers to Jesus? Since the name "Muhammad" linguistically derived from Arabic verb `hamada' meaning `he who is praised', these documentary sources could possible be referring to Jesus. There are at least five reasons why this is hopelessly fallacious.
1. There is not a shred of evidence. Nowhere does Spencer provide any evidence for this argument. He merely asserts it as a possibility. It would have been impressive if Spencer explored the Christian writings of the preceding centuries and produce an instance when they referred to Jesus as Muhammad or some cognate word. If he were able to do so his argument would have had some weight. Predictably he brings forth nothing. The only evidence is that it's possible.
2. Refuted by the Christian documentary sources for this period. When Caliph `Abd al-Malik decided to place `Muhammad is the Messenger of Allah' on Islamic coins, the Byzantine Emperor Justinian II (r. AD 685-95) starting minting coins with a portrait of Jesus (a `Christ Pantocrator') with the cross behind him and the Gospels in his left hand. These coins also bear the inscriptions "Jesus Christ, King of the Rulers", "Jesus Christ, Lord, Saviour, King of Kings", and "Emperor Justinian, servant of Christ". Thus we know what the Christian coins mentioning Jesus looked like. We know what was inscribed on them and we also know the controversy it led to in the Christian community. The Christian documentary materials do not refer to Jesus as `Muhammad'. They refer to Jesus as `Jesus Christ' or `Christ' as always. Furthermore the titles used for Muhammad and Jesus are different. Whereas Muhammad is referred to as `Servant' and `Messenger', Jesus is referred to as `Lord', `Saviour' or `King of Kings'. So not only is Jesus never referred to as Muhammad in the Christian documentary sources form the time, the phraseology is completely different.
3. Spencer failed to engage with the documentary evidence that directly refutes his linguistic word-play. He failed to mention the bilingual Greek-Arabic administrative papyri that clearly translate "Muhammad" as "Muhammad" in Greek. Further still, he failed to mention the Arab-Sasanian coins of Kirman which translate "Muhammad" as "Muhammad" in Middle Persian. So the Greeks held "Muhammad" as proper name, the Persians held "Muhammad" as a proper name, the Arab held "Muhammad" as a proper name, but Spencer wants us to believe it was not a proper name but "could have been" referring to Jesus even though all Christian documentary sources from the time refer to him as nothing other than Jesus.
4. The argument raises more questions than it answers. Too many awkward questions arise. Firstly, why now? Why did Christians, after 600 years, start referring to Jesus Christ as Muhammad? Why not continue with the name they always used, namely `Jesus' or `Christ'? Spencer provides no reason. It's just logically possible. Secondly, if the Christians of the seventh century referred to Jesus as Muhammad, then how do we account for the depiction of that Muhammad in their own texts? That Muhammad was clearly a person alive in the seventh century. That Muhammad was clearly an Arab. That Muhammad had a new religion. That Muhammad was a merchant. In their estimation, that Muhammad was a `false prophet', `a liar', and an `anti-Christ'. Why were they so hostile to this Muhammad if he was in fact their lord and saviour? Thirdly, if the Christians of the seventh century referred to Jesus as Muhammad, then why did they make a distinction between this Muhammad and Jesus himself? Some of there texts make mentions of Jesus in high esteem, but when they mention Muhammad, it's usually not so nice. If Muhammad was really Jesus, why did they make the distinction between him and Jesus? Lastly, if the Christians of the seventh century referred to Jesus as Muhammad, how do we distinguish that Muhammad from the Muhammad of eighth, ninth, tenth, eleventh, twelfth century Christian texts. Christian's never stopped referring to Muhammad in their polemic works. On what bases then does Spencer distinguish the Muhammad found in seventh century Christian texts from those of the subsequent centuries that become ever more sophisticated? One what basis does he distinguish the Muhammad found in the first century text of Armenian Christian Seboes from the Muhammad in the second century text of Greek Christian St. John of Damascus and both from the Muhammad in the third century Syriac Christian text of Dionysius of Tel-Mahre? They are all clearly the same Muhammad and they are all clearly references to the Islamic prophet.
5. How do we account for the Christian reactions to the documentary material? When Mu'waiyya became caliph in 660 CE, a contemporary Marionite Christian chronicler reports that that "He also minted gold and silver, but it was not accepted because it had no cross on it" [Palmer et al, The Seventh Century in the West-Syrian Chronicles, p32]. Why were Christians removing the cross from their own coins and replacing with Arabic Islamic phraseology? And why, having done that, did they protest about it? Why, as we have seen, would the Christian emperor Justinian react to the Muslim coins with `Muhammad is the messenger of Allah' inscribed by issuing coins with Jesus "Jesus Christ, Lord, Saviour, King of Kings".
The other strategy Spencer employed is omission. He simply pretends some first century documentary sources do not exist. Some of his omissions have been mentioned previously. They include the Christian coins which refer to Jesus as Jesus and not Muhammad. They include the bilingual papyri which mention Muhammad in Greek, the bilingual Arab-Sasanian coins that mention Muhammad in Persian. These sources provide a decisive refutation of his linguistic gymnastic with the name Muhammad. Also omitted is the first century tombstone of one Abasat ibnat Guraig which has inscribed: "In the name of Allah, the merciful, the compassionate. The greatest calamity of the people of Islam is that which has befallen them on the death of Muhammad the prophet... abassa ibnat Guraig died confessing that there is no God but Allah alone without partner and that Muhammad is his servant and messenger". For any sensible person, an inscription bearing the words "people of Islam", "Allah", "Muhammad" twice, and bears the Muslim testification of faith is unquestionably Islamic. Also ignored is the inscription that was on the Mosque of Damascus which read "Or Lord is Allah, Our Religion is Islam, and our Prophet is Muhammad..." This inscription reads almost as a creedal statement. How can Spencer refute all these documentary sources? He doesn't. He pretends they don't exist. When he knows that 99.9% of readers won't bother checking up on this, it turns out to be a very good strategy.
[6] What about his arguments against the Islamic texts. Spencer has no interest in providing his readers with a balanced overview of the scholarly views regarding the Muslim literary sources. He simply wants to rubbish them. So what arguments does he raise against the Islamic texts. Spencer has two prime arguments. Firstly, as we have it today, with the exception of the Qur'an, virtually all Islamic texts survive from the second, third and fourth centuries. Secondly, the literary sources contain contradictions, forgery, factionalism and manipulation brought about by sectarian dispute. As for the first, Spencer is certainly right if you disregard the crucial fact that those second, third and fourth century texts preserve some first century texts that have perished or survive in later manuscripts. That is, with the sole exception of the Qur'an, all of the first century Islamic texts are either preserved in later works as extensive quotations or survive in later manuscripts. For example, Hamam ibn Munabih, a student of the great companion Abu Hurayrah, composed a work of hadith called Sahifa Saheeha. This work of hadith is still preserved in two manuscripts housed in Berlin and Damascus, but both manuscripts are date from the third century. Likewise, it is widely known amongst historians that the great companion of the prophet, Abduallah ibn Amir al-Aas would write down sayings of the prophet Muhammad to aid his memorisation of them. His personal manuscript, called Al-Sahih al-Sadiqa, was preserved in manuscript form by his family until it was lost in the third century. However, it has been preserved completely for us by third century traditionalist Ahmed Ibn Hanbal who copied the entire manuscript into his own volumes.
Now, if Spencer denies first century works like the Sahifa of Hamam ibn Munabih on the ground that is lacks first century attestation, then he is not only demanding a standard that scarcely any ancient texts can satisfy, the same argument can be employed to undermine all the texts of the New Testament as none of them can satisfy such a demand. All historians agree that most of the New Testament were written during the latter half of the first century. However, we have no manuscripts of any of them in the first century For example, Mark is the first of our Gospels written a few years before AD 70. However, the earliest manuscript witness we have for it is in P45 dating AD 200-250; 130-180 years after the original. Similarly the works of Paul are the earliest in the New Testament but none of the surviving manuscripts [P10, P12, P13, P15, P16, P17, P27, P30, P32, P40, P46, P49, P65, P87, P92, etc] date from before the third century. This is not meant to be an attack on Christian texts, but to simply illustrate that this argument of his would ruin virtually all ancient text, but also the NT texts and those of the earliest church fathers.
As for the second argument, it's hardly anything new. It was Muslim historians and traditionalists who discovered these problems and developed sophisticated source critical methods with which to verify the reliability of a report. Put crudely, it contained three basic elements: (1) demand a source,(2) scrutinize the source, and (3) search for corroboration. This is first-rate source-critical method. This allows scholars to merely verify a report, but to trace its transmission history right back to the prophet. Can anyone fault this method? This system is unparalleled in any another civilization of the time. The Greco-Roman, Christian, Jewish, Indian, or Chinese historians didn't apply a fraction of the source-criticism Muslim historians and traditionalist applied to their material. Furthermore, if all the sectarian factions agreed on the major event in the prophets life, how can Spencer use sectarianism as an argument? This fact support the reliability of the soruces, not their unreliability.
As for the second argument, it's hardly anything new. It was Muslim historians and traditionalists who discovered these problems and developed sophisticated source critical methods with which to verify the reliability of a report. Put crudely, it contained three basic elements: (1) demand a source, (2) scrutinise the source, and (3) search for corroboration. This is first-rate source-critical method. This allows scholars to merely verify a report, but to trace its transmission history right back to the prophet. Can anyone fault this method? This system is unparalleled in any another civilization of the time. The Greco-Roman, Christian, Jewish, Indian, or Chinese historians didn't apply a fraction of the source-criticism Muslim historians and traditionalist applied to their material.
Much much more can be said about the book. I may expand by review to his stab at the Qur'an if I can muster the energy for such a futile thesis. This review though is based on the central thesis, the title of the Book. In summary, the book lacks any scholarly balance, opting instead to rely on the works of ultra revisionists. He started off the book with an ultra revisionist criteria of historicity that would make much history of Late Antiquity virtually unworkable. He also started off with the false assumption that the Arab-Muslims would conquer and instantaneously transform the North-Africa and the Near & Middle East in some Blitzkrieg like scenario when scholarship informs us that the earliest Muslim polity naturally took a couple of generations to flower into a State. His handling of the non-Muslim sources is selective and clearly contrived. So is his handling of documentary material. His treatment of the Muslim literary texts is superficial and one-sided. The book is poorly researched and replete with quoting other people quotes. And finally, the book is so full of suppositions and guesswork that no point is ever evidentially based enough to be demonstrated. One simply has to ask themselves the question. Suffice it is to say that Spencer has failed miserably to prove his thesis.".
