For example, al-Mas'udi and many other historians report that Moses counted the army of the Israelites in the desert. He had all those able to carry arms, especially those twenty years and older, pass muster. There turned out to be 600,000 or more. In this connection, (al-Mas'udi) forgets to take into consideration whether Egypt and Syria could possibly have held such a number of soldiers. Every realm may have as large a militia as it can hold and support, but no more. This fact is attested by well-known customs and familiar conditions. Moreover, an army of this size cannot march or fight as a unit. The whole available territory would be too small for it. If it were in battle formation, it would extend two, three, or more times beyond the field of vision.
How, then, could two such parties fight with each other, or one battle formation gain the upper hand when one flank does not know what the other flank is doing! The situation at the present day testifies to the correctness of this statement. The past resembles the future more than one (drop of) water another. Furthermore, the realm of the Persians was much greater than that of the Israelites. This fact is attested by Nebuchadnezzar's victory over them. He swallowed up their country and gained complete control over it. He also destroyed Jerusalem,their religious and political capital. And he was merely one of the officials of the province of Fars. It is said that he was the governor of the western border region. The Persian provinces of the two 'Iraqs, Khurasan, Transoxania, and the region of Derbend on the Caspian Sea were much larger than the realm of the Israelites. Yet, the Persian army did not attain such a number or even approach it. The greatest concentration of Persian troops, at al-Qadisiyah, amounted to 120,000 men, all of whom had their retainers. This is according to Sayf who said that with their retainers they amounted to over 200,000 persons. According to 'A'ishah and az- Zuhri, the troop concentration with which Rustum advanced against Sa'd at al-Qadisiyah amounted to only 60,000 men, all of whom had their retainers.
Then, if the Israelites had really amounted to such a number, the extent of the area under their rule would have been larger, for the size of administrative units and provinces under a particular dynasty is in direct proportion to the size of its militia and the groups that support the (dynasty), as will be explained in the section on provinces in the first book. Now, it is well known that the territory of the (Israelites) did not comprise an area larger than the Jordan province and Palestine in Syria and the region of Medina and Khaybar in the Hijaz.--Ibn Khaldun, The Muqaddimah, Translated by Franz Rosenthal.
The quoted passage is from the Introduction to the Muqaddimah. As I have noted before (here and here) the book is embedded in a framework derived from Aristotelian science.* To say this is revealing in lots of ways, but today I want to point to some of his evidential strategies -- Ibn Khaldun calls it "probing with the yardstick of philosophy...[and] the help of knowledge of the nature of things...speculation and historical insight" -- in which he anticipates methods we are more likely to associate with Spinoza and Hume. I have quoted the first, instructive example of the claim that "historians, Qur'an commentators and leading transmitters have committed frequent errors in the stories and events they reported." The underlying point is to show how one can do source criticism by appealing to non-demonstrative principles that, nevertheless, have the status of robust commitments or generalizations that help one constrain or interpret the data (or some causal claim, etc.). I will call such principles, practical, empirical generalizations.
Here are some such practical generalizations.
- [A] Every realm may have as large a militia as it can hold and support, but no more.
- [B] An army has [given technological and physiological constraints] a maximum size in which it can fight as a unit.
- The size of an army/militia is constrained by the requirements of battle-field communication;
- The size of an army/militia is constrained by field of vision;
- [C] The size of administrative units and provinces under a particular dynasty is in direct proportion to the size of its militia and the groups that support the (dynasty),
The epistemic status of such practical, empirical generalizations is grounded in or based on historical and practical experiences, reflection on human and social nature, underlying political economy, demographics, group psychology,and principles of analogy (etc.). As Ibn Khaldun says, he will show the robust veracity of [C] in a separate chapter. I don't mean to suggest that these are only empirical generalizations. For example, [A] borders on a tautology. But the point of [A] is not to offer an a priori truth, but to make the reader reflect on the demographic, geographic, and economic, !etc.) constraints on the possible size of a militia. And given the plausibility of such constraints [A] can, in turn, by an informed constraint on the interpretation of source material. (Hume is a master of using informed and empirically grounded constraints to sift data in his work on demographics and political economy. This works in both directions.)
In addition, in practice, [A-C] also assume a further principle of human nature:
- [D] that if military might exists, it will be used to expand territory until it gets checked by an opposing power.
This principle, [D], is the conatus/will-to-power principle of Ibn Khaldun's historiography. In order to avoid misunderstanding, I don't mean to suggest that for Ibn Khaldun that military power is sui generis or an explanatory primitive; it is grounded in group feeling, demography, economy, leadership qualities, etc.
Of course, some of the claims that Ibn Khaldun's source criticism relies on are not merely such practical generalizations, but they are connected to more fundamental metaphysical principles. So, for example, one of the principles he explicitly relies (again see the quote above)on is this:
- [E] The past resembles the future,
That Ibn Khaldun embraces [E] is especially notable because he also thinks an unthinking reliance on a version of [E] is simultaneously one of greatest dangers in the writing history because it can license (i) a form of anachronism that prevents understanding of the past (this is familiar enough), and (ii) also (and more interesting) a misunderstanding of the present based on familiarity with works of history. The example he offers is that the content and status of particular political and legal offices have, without changing names, dramatically shifted in character. So, he claims that in the early caliphate and also the conquest of Spain a judge was often somebody who either had the power of the sword or was very closely affiliated to the center of power (due to group feeling); in his own age the judge is more an administrative functionary.+ Contemporary readers, may misunderstand their own time, and "aspire to similar positions" if they think that judges are still at the center of political power.
The last paragraph also hints at the fact that point of source criticism for Ibn Khaldun history is not just an understanding of the past, but also a better understanding of the present. In addition, Ibn Khaldun recognizes that works of history can motivate readers to courses of action. Some other time I return to that.
Here I want to close with a final observation because the title of this post promises something riviting than Ibn Khaldun's source criticism. In the quoted passage, Ibn Khaldun calls attention to the greatest military victory of early Islam, the battle at al-Qadisiyah. In this battle the numerically inferior Arabs defeated one of the great superpowers of the Ancient worlds, the mighty Persian Sassanid empire. It opened the 'East' to Muslim expansion. The significance of the battle would have been familiar to Ibn Khaldun's readers and a source of group pride.
Ibn Khaldun's official point of reminding the reader of this famous battle is to undermine the plausibility of historians's reports that Moses's army turned out to be 600,000 or more. Such an army would have been the basis of world domination not the occupation of a small bit of territory. Ibn Khaldun deftly shows that this number is implausibly large.
The interest of the example is, however, not just illustrative correction of bad scholarship. There is a more important point lurking here. For the implausibly large number is (as is well known) in the Biblical source-material. Numbers 1: 45-46 states, "And all those that were numbered of the children of Israel by their fathers' houses, from twenty years old and upward, all that were able to go forth to war in Israel; even all those that were numbered were six hundred thousand and three thousand and five hundred and fifty." As it happens, the Quran recounts the story of exodus and the further exploits of Moses and Israelites, but without the claim to (exaggerated) exactitude of the sort the Hebrew Bible offers.
So, it is quite clear that the historians that Ibn Khaldun criticizes have embellished their account of the Biblical history re-narrated by the Quran by glancing at the Hebrew Bible (itself a sacred text familiar to Muslim scholars). The error is in the historical source not just the scholarship. What to do? After engaging in such source criticism, a pious and prudent scholar can't respond by claiming that the error "occurs only in the Torah which as is well known, was altered by the Jews" (for reasons of self-aggrandizement, bias, etc.). Even to an Islamic scholar this response is unavailable "since custom prevents people who have a revealed religion from dealing with their divine scriptures in such a matter."
The problem is obvious, if one allows that sacred Hebrew scripture has been corrupted by interests motivated by group-loyalty one is stuck claiming that it is possible other sacred scriptures could also have been corrupted. This is the road to Spinozism.
From the vantage point of Spinozism, Ibn Khaldun's response is disappointing. He claims that such passages have to be treated as miracles. This is not the end of the matter, of course, because one must understand what a miracle is. But that's for another time. Here I close with the observation that for Ibn Khaldun one can only speak of such miracles after engaging with source criticism. And this means that he has quietly invited us to apply his methods also to the Quran.
*I recently read a beautiful, draft paper by Peter Adamson that makes that case in scholarly fashion. We are both indebted to Muhsin Mahdi.
+The example, can also be found in Ibn Rushd's Commentary on Plato's Republic.