CONDITIONS (Heb. תְּנָאִים, tena'im).
Conditions is an ambiguous word inasmuch as it refers not only to the external factors upon which the existence of an agreement is made to depend but also to the actual terms of the contract itself. Thus, one speaks of tena'ei ha-ketubbah, which really means the terms of the ketubbah. Similar ambiguities exist in English law (see G.C. Cheshire and C.H.S. Fi-foot, The Law of Contract (19605), 118ff.). In Jewish law, there is a further contingency: tenai consists not only of the stipulations of the contracting parties but also refers to legislative provisions, as evident in the expression tenai bet-din (see *Takkanot). As to conditions proper, i.e., stipulations (qualifications or limitations) attaching to a principal agreement, the basic concept in Jewish law seems to be very much the same as that in other systems of law. For example, distinctions between conditions precedent and conditions subsequent, differentiations between affirmative and negative conditions, between authoritative, casual, and mutual conditions or between expressed and implied conditions, and much more are found in all legal systems, although in Jewish law they may not be so clear-cut terminologically.
A vital characteristic of conditions in Jewish law is the provision referred to as tenai benei Gad u-venei Re'uven, based on Numbers 32. This was the occasion when Moses allocated land to the tribes of Gad and Reuben (and to half the tribe of Manasseh) on the east side of the Jordan River on the condition that they crossed the Jordan and assisted the other tribes in the conquest of the Holy Land. The Mishnah notes (Kid. 3:4) that when Moses made this stipulation he used a tenai kaful ("double condition"), expressing himself, i.e., both in the affirmative and the negative: if they fulfill the condition, they
It is remarkable that the codes just referred to cite these rules in the context of matrimonial law, but it is the express opinion of Maimonides (ibid., 6:14) that they apply equally to other provinces of the law, e.g., to *sale and *gift, and he persists in his ruling, despite the fact that later Geonim (to whom he explicitly refers) would have the formal requirements of tenai kaful and hen kodem le-lav apply to kiddu-shin (see *Marriage) and gittin (see *Divorce) only, and not to matters covered by laws of mamon. Maimonides aptly argues that the biblical "precedent," from which the present law is derived, concerned mamon ("acquisition of property"), and it would therefore be illogical to consider it as applicable only to matrimony rather than to matters of mamon. Nevertheless, in light of the glosses and commentaries to Maimonides (Maim. Yad, Ishut 6:14, and Zekhiah u-Mattanah 3:8), there is good authority for restricting the said requirements to kiddushin and gittin; and there is logic, too, in freeing everyday transactions from unreasonable formal requirements, since the predominant factor should be the will of the parties – and if they want a certain condition to be fulfilled, it should stand even if formalities like tenai kaful have not been observed (Rabad ad loc). Moreover, *custom, which is a powerful agent in Dinei Mamonot, may have regarded such a requirement in the field of commercial transactions as obsolete (Haggahot Maimoniyyot to Ishut 6:14). Yet, even if the halakhah were to be decided as suggested by Maimonides, there still exist various means of evading the problems arising out of the formalistic requirements of tenai kaful and hen kodem le-lav. Maimonides himself notes (Ishut 6:17) that if the word me-akhshav ("from now") was used in the stipulation, which would seem to turn a suspensive condition into a resolutive one, the requirement of tenai kaful may be ignored. Equally, the use of the words al menat ("provided that"), as distinct from the simple im ("if "), has the same effect as me-akhshav (Sh. Ar., EH 38:3). Furthermore, if the condition is contained in a written document, the date of the document could have the effect of me-akhshav (Git. 77a).
Already in the Middle Ages, when most of the transactions among Jews were in chattel, there seems to have been a tendency to consider the tenai benei Gad u-venei Re'uven, if applicable at all, as being restricted to the transfer of landed property (as was the case, in fact, in the original "deal" with the tribes of Gad and Reuben); pure obligations (in personam), not involving the transfer of property, would then certainly be exempt from those rules (see Gulak, Yesodei, 1 (1922), 80). It may be mentioned in this context that some "reservations" (shi'ur) do not fall under the term "condition." For example, if one sells his house, but reserves the right to a certain part of it, this is not construed as the vendor having said that he would sell the house "on condition that…"; therefore the requirement of tenai kaful, etc., does not apply (Sh. Ar., HM 212:3).
The requirement that the conditions should be capable of fulfillment, which is the most reasonable requirement and applies regardless of the form of the stipulation, needs some elaboration. The consequence of stipulating an impossible condition is that the principal transaction remains valid, despite the "nonfulfillment" of the condition (Maim. Yad, Ishut 6:7). By contrast, in Roman law the whole transaction would be voided by the defect of the condition (for a further discussion of this point, see Gulak, loc. cit., 81). It should be said at once that this is not the case of a person being prevented from fulfilling a condition by reason of force majeure (see *Ones), but with conditions stipulating something which according to all human experience is a priori impossible. The example usually given in the sources is "if you climb to the sky." Moreover, only physical and not moral or legal impossibility is visualized in this context. For example, if one promises to give his horse to another on the condition that the prospective recipient commits a sin, the condition would stand, and if he committed the sin, he would have the horse; if not, he would not (Maim. Yad, Ishut 6:8; EH 38:4). For a discussion of the problems of jus dispositivum jus cogens, and illegal contract, see *Contract.
A final category, widely discussed, is that of implied conditions. The classic case is that of a man who sold his possessions because he intended to immigrate to the Holy Land, but made no mention of his intentions during the negotiations. His plans having been foiled, he then wanted to renege on the transaction, arguing that he only sold his possessions on the condition that his plans would be realized. The ruling here is that such mental reservations have no effect ("words which are in the heart are not words," Kid. 49b–50a). This does not mean that only explicit conditions are valid; in fact, it is sufficient if in the circumstances, the dependency of the transaction on certain events was clearly apparent. For example, if a person, in contemplation of death, donated all his property, it is assumed that he did so on the premise that his death was imminent (especially if the donation was made during a particular illness). Accordingly, if he survived, the donation is ineffective (BB 9:6; see also *Wills). On the general question as to whether and to what extent the parties are bound by the transaction before the condition is fulfilled (Maim. Yad, Ishut 6:15–16; Sh. Ar., EH 38:6–7), it should be noted that, here again, conditions introduced by the simple im would lack forcefulness, which can be remedied by the addition of me-akhshav or by using the formula of al menat, a differentiation discussed above in connection with tenai kaful (see also *Asmakhta). Special problems of conditions attaching to specific transactions
Gulak, Yesodei, index; N. Wahrmann, Die Entwicklung der Bedingungsformen im biblisch-talmudischen Recht (1929); idem, in: Zeitschrift fuer vergleichende Rechtswissenschaft, 45 (1930), 219–39; idem, Die Bedingung תנאי und אסמכתא im juedischen Recht (1938); Herzog, Instit, 2 (1939), 217ff.; B. Cohen, in: H.A. Wolf-son Jubilee Volume (1965), 203–32; also separately: Conditions in Jewish and Roman Law. ADD. BIBLIOGRAPHY: M. Elon, Ha-Mishpat ha-Ivri (1988), 1:352, 520f., 574f., 735, 754f.; 2:1285; 3:1480; idem, Jewish Law (1994), 11:424; 2:632f., 707f., 906, 930f.; 3:1533; 4:1760f.; idem, Ma'amad ha-Ishah (2005), 114–15; M. Elon and B. Lifshitz, Mafte'ah ha-She'elot ve-ha-Teshuvot shel Ḥakhmei Sefarad u-Ẓefon Afrikah, 2 (1986), 536–39; B. Lifshitz and E. Shochetman, Mafte'ahha-She'elot ve-ha-Teshuvot shel Ḥakhmei Ashkenaz, Ẓarefat ve-Italyah (1997), 360–61.