2.2 “Custom Overrides the Halakha” and Qinyan Siṭumta
The Geonim had a juristic tool at their disposal that they could deploy when faced with discrepancies between Talmudic law and contemporary merchant practice recognized by Islamic law. This was represented by a rabbinic maxim, minhag mevaṭṭel halakha, “custom overrides the halakha,” analogous to an Islamic legal maxim, al-‘āda muḥakkima, “custom is legally authoritative.”20 The Jewish maxim appears in the Palestinian Talmud.21
The Talmudic precedent for this concession to daily economic affairs occurs in connection with transfer of ownership (Heb., qinyan). Recognizing the necessity for flexibility when buying and selling, the Talmud validates a procedure called siṭumta (meaning “a seal”), which, if it conformed with local custom, could substitute for one of the methods of acquisition dictated by the Talmud, such as physically pulling the object (meshikha) or lifting it up (hagbaha). The example given by the Talmud is wine. The medieval commentator Rashi, thinking of the importance of wine as a commodity in his own time and place in eleventh-century France, explains the notion as follows. When a retailer purchases barrels of wine for his shop from a winemaker, he does not take all of them at once but leaves some in the seller’s wine cellar to be claimed later, as needed. He marks the kegs with a siṭumta to identify them as his own. This procedure signifies proof of purchase and substitutes for “pulling” the object.22 As summed up by R. Solomon b. Adret (Rashba; thirteenth-century Spain), “we learn from this that custom overrides the halakha [minhag mevaṭṭel halakha] as well as in any similar matter. In all monetary matters, one may buy and sell in accordance with custom. Therefore, one may complete a purchase in whatever way it is customary for merchants to do so.”23 Rashba’s rule echoes, further, an axiom of economic history: mercantile custom typically evolves out of the needs of the marketplace, in contexts connected with trade, rather than in schools of law.24
2.3 Trade and the “Custom of the Mariners”
The importance of custom in Jewish economic life is attested in the Talmud in a concession to practice in the surrounding society that was to prove essential for long-distance trade during the Islamic period. I refer to what the rabbis call minhag ha-sappanim, the “custom of the mariners.”
Classical rabbinic literature, it has been observed, contains a paucity of nautical terms.25 While the Mishna, the Tosefta, and the Talmuds contain occasional discussions of legal issues relating to sea travel, which some have argued represent traces of an indigenous Jewish “admiralty law,”26 these scattered fragments do not bespeak a widespread phenomenon of long-distance trade by ship that would have required detailed halakhic regulation.27 Stories in rabbinic texts about arriving in or traveling to medinat ha-yam, literally, “the land of/by the sea,” apparently originally meant not across the high seas but rather the Mediterranean coastal district of Palestine. Only later did this term assume the meaning of beyond the shores of the Land of Israel, namely, the lands of the Hellenistic diaspora at the eastern end of the Mediterranean.28
When Jews did travel by ship, for study, to visit family, to find a wife, or occasionally on business, they followed the custom of the mariners, a set of practices devised and put into practice by seafaring people in the society in which Jews lived. Classical rabbinic law mentions this concept once, in the Talmudic tractate Bava Qamma 116b, with a parallel in the Tosefta. Notably, the case regarding sea travel is preceded by an example concerning overland transport by donkey caravan, where the concept of the “custom of the mariners” is replaced by the “custom of the ass-drivers.”
[1] Our Rabbis taught: If a caravan traveling in the desert was attacked by armed men threatening to plunder it [le-ṭorfah], they reckon [the contribution to be paid by each merchant to buy them off] according to the monetary value [of the goods of each merchant] but not according to the number of souls. But if they hired a guide to go ahead of them, they also reckon [compensation for the loss] according to the number of souls [in the caravan]. They must not deviate from the custom of the ass-drivers.… [2] Our Rabbis taught: If a ship traveling on the sea was hit by a storm threatening to sink it, so that they jettisoned some of the cargo [lit., “lightened its weight”], they reckon [indemnification for the loss] according to the weight of the cargo and not according to its monetary value. They must not deviate from the custom of the mariners.29
The case in the Talmud recalls the rules of jettison and general average (equalized division among all merchants of responsibility for overall loss through jettison) in the ancient Roman law of the sea. This law was summarized later in Justinian’s Digest (sixth century) and elaborated subsequently in the Nomos Rhodion Nautikos (Rhodian Sea Law), thought to have been compiled between 600 and 800 C.E.30 Boaz Cohen, the eminent scholar of comparative Jewish and Roman law, pointed to the similarity between the maritime law of salvage in the classical rabbinic sources and in Justinian’s Digest.31
In an important book comparing the Rhodian Sea Law with Islamic maritime law as reflected in Islamic fatwās and in the Arabic Kitāb akriyat al-sufūn wa,’l-nizā‘ bayna ahlihā (“Treatise Concerning the Leasing of Ships and the Claims Between [Contracting] Parties”), Hassan Khalilieh argues that these rules from the late Roman Empire were mediated into Islam by local, Greek-speaking non-Muslims and “Islamicized” to conform with Qur’ānic and prophetic principles.32 An example from Islamic maritime law would be the requirement that all shippers share in losses incurred when jettisoning cargo.33
The regulation in the Talmud that apportionment of loss among the travelers should be determined by weight and not by the monetary value of the jettisoned items addresses one of the basic issues in ancient and medieval legal discussions of jettison, though in Justinian’s Digest and in virtually all medieval laws of jettison, the preference is for calculation by monetary value rather than by weight. Logically, weight was the primary consideration at the moment of jettisoning, though monetary value took center stage when merchants came to settle accounts later on.34 In a parallel halakha, the Palestinian Talmud (Bava Meṣi‘a 6:4, Venice edition 11a) stipulates that apportionment of loss is by both weight and value, evidently reflecting the dual consideration that operated in cases of jettison.35
The great diversity of rulings on jettison in ancient and medieval legal sources led Olivia Constable to surmise that “they must have reflected local practice and a common understanding of the basic principles of general average.” She illustrates this with diverse opinions in Islamic maritime laws about how to assign value to goods cast overboard.36 The Talmudic statement “they must not deviate from the custom of the mariners,” supports her assumption that customs varied from place to place and shows that, in the absence of halakhot covering maritime law, the rabbis of the Talmud and, in this respect, Maimonides as well, recognized and enforced customary practice current in the surrounding society.37 This precedent later informed the halakhic “policy” recognizing non-Jewish shipboard law when Jewish merchants traveled with their goods on ships owned by non-Jews, usually Muslims.38
With the coming of Islam, many new commercial customs came to the fore that required juristic attention and accommodation in the halakha. This process was begun relatively early by the Geonim, chiefly by granting commercial customs practiced in the Islamicate marketplace the force of law, exemplified by their legalization of the suftaja.39 Maimonides, who inherited the legal tradition of the Geonim and of his teachers in al-Andalus, expanded on the foundation laid by his predecessors, carrying their work of responding to the realities of the marketplace to a new level of attainment through the process of codification in the Mishneh Torah.
2.4 The Custom of the Merchants in Maimonides’ Code
Maimonides is likely to have been exposed to the custom of the merchants already during his youth, growing up in the commercial milieu of Muslim Spain and North Africa.40 Upon his arrival