SEVARAH , the legal logic employed by halakhic scholars in their reasoning. This logic is founded on observation of the characteristics of human beings as they are disclosed in their social relations with one another and on a study of the practical realities of daily life. Sevarah may serve both as a historical source of law – a source which factually and indirectly leads to the creation of a particular legal rule – and as a legal source of law – a source recognized by the particular legal system as a direct means for the acceptance of a legal rule into that system. (On the different sources of law, see *Mishpat Ivri.) Logic may also serve as a historical source in the functioning of the other legal sources of Jewish law. Thus, for instance, when a particular legal rule is created by means of the legal source of Midrash (see *Interpretation), the interpretative activity constitutes the direct creative source of that rule; however, the interpreter is guided along his interpretative path by logic and reasoning, which therefore form the historical-factual source of the rule. The same is true of rules created by means of legal sources of legislature, that is *takkanah, *ma'aseh, and *minhag, where the rules are naturally created and fashioned as the outcome of certain needs as dictated by logic and practical exigencies. It is as a historical source in the aforementioned sense that sevarah is quoted as a basis for the study and understanding of the halakhah (see, e.g., Git. 6b; Shab. 63a; Suk. 29a, et al.). On the other hand, sevarah functions as a legal source whenever it serves as the direct source of a particular rule, that is whenever such rule is created by virtue of logic and reasoning alone, outside the framework of and without assistance from any other legal source such as Midrash, minhag, or ma'aseh.
An important place is assigned to sevarah as the creative source of halakhic norms in all fields of the halakhah, whether in relation to the precepts between man and his Maker or the laws pertaining to relations between man and his fellow man in matters of ritual law or civil law. The high regard in which sevarah was held also finds expression in the manner of the laws originating from this legal source. Thus a law having its creative source in takkanah or minhag is numbered among the category of laws known as de-rabbanan (see *Mishpat Ivri), whereas a law having its direct source in sevarah is generally numbered among the category known as de-oraita (Chajes, in bibl., and see below). The honorable status thus lent a rule originating from sevarah is attributable to the fundamental principle which underlies the whole of the halakhic system, namely, that the Torah was given on the authority (al da'at) of the halakhic scholars (see *Authority, Rabbinical); hence every rule founded on the logical reasoning of the halakhic scholars originates, as it were, from the Torah itself, because the logic of the halakhic scholars corresponds with the logic embodied in the Torah.
Sevarah as the Creative Source of General Legal Principles
It is an important principle of Judaism that a person who is told to transgress or else suffer death should transgress rather than be killed (Sanh. 74a), since the laws of the Torah were given so that man should live by them and not die because of them (Yoma 85b; Yad, Yesodei ha-Torah 5:1). However, in three cases a person given the choice between transgression or death should choose the latter; idolatry, incest (including adultery), or murder (Sanh. 74a; Pes. 25a–b; et al.). As regards idolatry and incest the rule was established by way of biblical exegesis (Sanh. 74a), but with regard to murder the rule was derived logically, and not by way of exegesis, as follows: "The sevarah is… who shall say that your blood is redder? Perhaps the blood of the other is redder!" (Sanh. 74a); for "as far as the murderer is concerned, since in the end man is anyhow destined to die, why should it be permissible for him to transgress? Who knows that the Creator holds his life to be of greater worth than that of his fellow?" (Rashi, ad loc.). Thus the rule in regard to the shedding of blood a person should choose death rather than transgression has its legal source in sevarah.
There are a considerable number of general legal principles operating in the field of both ritual and civil law which similarly originate from the legal source of sevarah. The rule that the burden of proof is on the claimant is derived from logic on the reasoning that just as the person who has a pain seeks out a doctor and recites his symptoms (and it is not the doctor who runs around to find out who is ill), so too the person who has a claim against another must first bring proof to substantiate his claim, and the defendant need not first prove that he is not liable on such claim (bk 46b). So too a woman's statement that she was married and became divorced – there being no witnesses to the fact that she was married – is believed as regards her becoming divorced, in terms of the rule pertaining to the laws of evidence that "the mouth which has rendered prohibited is the mouth which has rendered permissible"; this rule is derived from the logical reasoning that since she prohibited her own self (to others) she may also permit her own self (Ket. 2:5; Ket. 22a; from this rule there was derived in amoraic times the rule of miggo; see *Pleas; *Evidence).
The two aforementioned rules are expressly stated as having their legal source in sevarah, and this also appears to be the case with reference to a number of further rules and principles, for instance as regards the principle of ḥazakah as a legal presumption – such as the presumption that a person is alive (Git. 3:3), the presumption of legal competence (ḥezkat kashrut; bb 31b), the presumption of bodily fitness (Ket. 7:8), and numerous other kinds of presumptions. Logic is also the source of the rule regarding reliance on the majority, even when the majority is not a factual one (such as a majority of the judges hearing a particular case), but is based on surmise alone [Ḥul. 11a; the biblical passages cited there with regard to several kinds of majority and ḥazakah are in the nature of *asmakhta ("mere allusion") alone; see also *Interpretation]. These presumptions have validity in all fields of the halakhah, in matters of the civil law as well as matters of ritual prohibitions and permissions, and even in matters which are deoraita: "For matters learned by way of sevarah are of the same value as the actual statements of the Torah itself… since the power of observation deriving from experience is of precisely the same value to them [the halakhic scholars] as a matter learned through application of the exegetical middot" (see *Interpretation; Chajes, in bibl., 118–30).
Sevarah in the Amoraic Period
A substantial proportion of the laws and principles deriving from sevarah are attributable to an early period of the halakhah. From talmudic sources it is also possible to conclude that the use of sevarah as a legal source of the halakhah was particularly resorted to during amoraic times – just as the amoraim laid down rational rules with regard to the use of other legal sources and the modes of studying the halakhah (see *Takkanot; *Asmakhta). Thus in regard to forbidden food and drink R. Johanan laid down that the taking of even half of the determined measure was also forbidden by the pentateuchal law – since one half-measure may combine with another half-measure to constitute a full measure, it follows that he will be eating that which is forbidden (Yoma 74a). The amoraim stated that in respect to various laws it may be said that they have their source either in a biblical passage or in sevarah, for instance as regards certain matters relating to the laws of evidence (Sanh. 30a), the laws of ḥaliẓah (Yev. 35b) and in other fields (see, e.g., Shevu. 22b and Tos. loc. cit.).
In other cases the amoraim searched for the legal source of a particular rule and came to the conclusion that such a rule had its origin in the legal source of sevarah. An interesting illustration of this is to be found in the discussions of the amoraim concerning the legal source of the rule that three years' possession of real property confers presumptive rights of ownership (i.e., upon a claim of lawful acquisition with subsequent loss of the title deed, but with possession for the said period without protest from the former owner; see *ḥazakah). The amoraim confronted difficulties in attributing the source of the rule to Midrash (see *Interpretation) and to Kabbalah (see Mishpat Ivri) in turn, and then Rabba determined the legal source of the rule thus: "The first year a person guards his title deed and so he does the second and third years; thereafter he guards it no longer" (bb 28a–29a). That is to say, logic – which is founded on the observation of daily practical life – teaches that a person who purchases property takes care to guard his title deed for a period of three years as proof against any challenge to his right in such property; however, after three years have elapsed without any such challenge, he no longer sees need to guard the material evidence of his ownership since he is already sure that he is fully in possession of the property and does not contemplate the possibility that his right to it will any more be challenged. This sevarah was accepted as the legal source of the rule that three years' possession of property suffices to prove the possessor's acquisition thereof according to law, even when the latter cannot produce his title deed or any other proof (for additional substantiation of the rule, see *Ḥazakah).
Sevarah continued to be a creative legal source in the post-talmudic period. However, the halakhic literary sources of this period, unlike those of the talmudic period, do not generally specially emphasize the fact that certain rules have their source in sevarah, as is generally done in the case of minhag, takkanah, and other legal sources. Hence painstaking research is required in order to distinguish the post-talmudic halakhic literary principles which originate from sevarah.
Weiss, Dor, 2 (19044), 48f.; J.M. Guttmann, in: Devir, 2 (1924), 128–30; Ch. Tchernowitz, Toledot ha-Halakhah, 1 (1934), 151–63; Z.H. Chajes, The Student's Guide Through the Talmud (19602), 29–31, 118–30; M. Elon, in: ilr, 2 (1967), 550. add. bibliography: M. Elon, Ha-Mishpat ha-Ivri (1988), 1:122ff., 805–28, index; idem, Jewish Law (1994), 1:137ff., 987–1014, index; idem, Jewish Law (Cases and Materials) (1999), 97–98; Enẓiklopedyah Talmudit, vol. 10, s.v. "harḥakat nezikin" 628, 644; index.