On Things, Theseus and Tum’ah: Metaphysical Underpinnings in the Talmud

BY: Dani Lent.

“Metaphysics attempts to tell the ultimate truth about the World, about everything. But what is it we want to know about the World? What are the questions whose answers would be the ultimate truth about things?”[i] This formulation of the study of metaphysics would seem to find its answer in the succinct declaration that “there is no truth other than the Torah.”[ii] This implies that, should one want to know the ultimate truth about the World, the most general features of reality, the appropriate reference book would be the Torah and, more specifically, the Talmud. Often, however, the philosophical lessons of the Talmud are lost amidst the halakhic discourse. Most philosophical and metaphysical exposition of the Talmud focuses solely on the aggadic passages. However, the legal discussions, which far outweigh the aggadic portions of the Talmud, can yield just as much philosophical reasoning when read critically.

A central discussion among metaphysicians is the question of identity. Defining what an individual thing is and how that one thing has a separate identity from everything else is a necessary topic in any study of metaphysics.[iii] Two theories that have been proposed in answer to this question are Nihilism and Monism. Nihilists believe that there are no individual things, whereas Monists subscribe to the theory that there is only the One thing and everything else is just a manifestation of it. Each of these views stands in contradiction to the common Western view that there are individual things—unique arrangements of particles in space.[iv]

This “common view” does not resolve all the metaphysical problems in the identification of objects for Western philosophers. Thomas Hobbes best poses the problem in his treatment of the metaphysical problem of Theseus’s ship: if each plank on Theseus’s ship were replaced with an identical plank such that none of the original planks remained in the ship, is the resultant vessel still Theseus’s ship? If the planks that were originally on Theseus’s ship were collected and formed into another ship in their original arrangement, is that vessel Theseus’s ship?[v] What is an object and how much must an object be changed for it to become a new object? More importantly, why do these questions matter?

The identity of an object is an issue of great import in the Talmud. It can be argued that Talmudic discourse is one of the only areas in which questions of identity impact anything other than a philosophical understanding of reality.[vi] A passage highly relevant to this topic, which I will quote in full, is the discussion of panim hadashot, literally “a new entity,” presented in the Talmud:

“We learnt elsewhere: As for all utensils belonging to private people, their standards are [holes as large] as pomegranates. Hizkiyyah asked, What if it [a utensil] acquires a hole [large enough] for an olive to fall through, and he [the owner] closes it, then it receives another hole [large enough] for an olive to fall through, and he closes it, [and so on] until it is made large enough for a pomegranate to fall through? R. Yohanan said to him, Rebbe, you have taught us: If one of the straps of a sandal is broken and he repairs it, [the sandal] still retains tum’at midras [vii]. If the second [strap] is broken and he repairs it, [the sandal] loses tum’at midras but retains magga tum’at midras.vii Now we asked you, “What is the difference between [a case in which] the first [is broken] and the second is sound and [a case in which] the second is broken and the first is repaired?” And you answered us, “panim hadashot have entered here.” Here too [in the case of the dish] panim hadashot enter. He [Hizkiyyah] exclaimed concerning him [R. Yohanan], “This one is not the son of man!” [or] according to others, “Such a one is indeed the son of man!” [viii]

This Gemara discusses the mending of utensils, kelim, and the subsequent applications of the laws of purity and impurity, taharah and tum’ah. A repaired wooden dish is only halakhically considered to be a new dish if the size of the patch is large enough for a pomegranate to fit through.[ix] This asserts that an object obtains a new identity, and, consequently, will no longer be tame, impure, if it is changed to the extent that the repaired part comprises a substantial portion of the keli.[x] The concept of panim hadashot, first discussed in regard to repairing the leather straps of a sandal, is applied by R. Yohanan to the gradual breaking and mending of a wooden dish, and the Gemara sees this analysis as deserving of great praise. What was so groundbreaking about R. Yohanan’s sevara, his logic, in applying a known principle to a new case? Is this not done on nearly every page of the Talmud with no praise accorded to its practitioners?

Eli Hirsch, a professor of philosophy at Brandeis University, attempts to answer these questions through a metaphysical reading of this Talmudic passage. At first glance, R. Yohanan’s explanation of the case of the wooden dish seems like a violation of the philosophical axiom “transitivity of identity.” This law, accepted by seemingly all philosophers in regards to identity, states that if x=y and y=z, then z must necessarily be equal to x. In relation to the case of the keli, if a small change is made to the keli, the original keli is still the same keli as the changed one. If this keli is then changed a little more, the keli has the same identity as it did after the first change. If this is true, it would seem impossible that a series of small changes, each only large enough for an olive to fall through, would lead to a loss of identity once the cumulative (though filled) gap is large enough for a pomegranate to fall through.

R. Yohanan’s appeal to the case of the leather sandal can help explain the logically problematic resolution arrived at in regard to the case of the wooden dish. The leather sandal discussed in this sugya is one that can function with the loss of one strap but not both. The straps themselves are not capable of acquiring tum’ah on their own because they have no utility when not attached to the keli, the sandal. The sandal, on the other hand, is capable of acquiring tum’ah, as are the straps when attached to it.[xi] Tosafot explain that the case here is where the first tum’ah, midras, is acquired from the outset, when there are two intact straps. The second type of tum’ah, magga midras, is acquired by the sandal when the first strap is replaced. Tosafot then continues that panim hadashot, the principle of acquiring a “new identity,” does not apply to tum’ah acquired at the middle stage, when only one strap is replaced. That is why midras, acquired at the initial stage, is lost once both straps are replaced, while magga midras is retained in the final state of the object.[xii]

Hirsch explains how Tosafot’s formulation of the case is not a violation of the transitivity of identity. In the initial state, the sandal (S) exists with both original straps (T1 and T2) attached and two separate kelim can be derived from the initial keli. Each possible keli results from the presence of just one of the straps and can be denoted A1 and A2, corresponding to each of the straps, respectively. It is at this point that tum’at midras is acquired. In the middle stage, after one of the straps has been broken and repaired, S still exists along with T2 and A2 (the second original strap and its derived keli). Now, however, there exists T1’ and A1’, which correspond to the new strap and its derived keli and it is at this point that tum’at magga midras is acquired. At the final stage, after both straps have been repaired, S no longer exists according to the principle of panim hadashot. Instead, there are T1’, T2’, A1’ and A2’. Tum’at midras is no longer present because there is nothing from the original sandal in existence, while tum’at midras mag’ah still applies because it was acquired in the middle stage, when T1’ and A1’ were already in existence. According to Hirsch’s interpretation of Tosafot,  the threat to transitivity of identity does not exist in this case because there is no keli, derived or whole, in existence that was already in existence at the initial stage.[xiii]

As mentioned above, R. Yohanan’s great sevara lies in his application of this concept of panim hadashot to the case of the wooden dish. The more obvious application of panim hadashot regards functional changes in an object. For example, a goatskin bottle that is converted into a rug no longer retains its tum’ah, [xiv]while a cowbell that is made into a doorbell still retains its tame status.[xv] In the former case the object is changed so that it has an entirely new function, while in the latter case the basic function remains the same, so panim hadashot does not apply. R. Yohanan reformulated the principle of panim hadashot to include not just functional changes, but also compositional changes. He appealed to the case of the leather sandal to show that it was not a functional change (i.e. from a fancy shoe that can be worn to a meeting to a repaired shoe meant for wearing around the house) but a compositional change that was the deciding factor. He used related this new idea, that a compositional change to an object could remove its status of tum’ah, to explain the case of the patched-up wooden dish. It was this new application of panim hadashot that won R. Yohanan widespread praise.[xvi]

Thomas Hobbes, about fifteen hundred years after this discussion in the Talmud took place, addressed the ongoing problems in regard to how to understand an object’s identity. He states, “Some place individuality in the unity of matter; others in the unity of form.”[xvii] I view Hobbes’s formulation of the existing views of identity as a correlation of the two variant applications of panim hadashot that Hirsch ascribes to R. Yohanan. The unity of matter, the individuality that gives an object its function, is not complete without the unity of form, the individuality of an object’s unique composition in material and structure. In support of the unity of matter theory, Hobbes posits that wax is the same no matter what shape it is in. In support of the unity of form theory, he draws upon the example of a man who, despite the fact that his cells are constantly changing, is the same man at the start of his life as at the end of it. R. Yohanan’s application of both compositional and functional changes to panim hadashot pertains to these cases in that wax changes function but not composition when it changes shape, while man changes composition over the course of his life but not function. Both retain their former status as the original object, despite these changes. Attaining the status of a new object due to either functional or compositional changes seems to be unique to the area of panim hadashot.

R. Joseph B. Soloveitchik connected the metaphysical idea of a priori concepts, knowledge that is obtained prior to experience, to the area of Halakhah. In Halakhic Man he writes, “The theoretical Halakhah, not the practical decision, the ideal creation, not the empirical one, represent the longing of the halakhic man.”[xviii] The concept of panim hadashot represents just such an idea. Wittgenstein’s approach to philosophy favored a multitude of examples with principles serving as an abstract framework from which to approach reality. The Talmud operates in a similar vein: there is no explication of the principles guiding the halakhic process at the very start. Rather, through the examination of the sea of examples, involving everything from sandals to doorbells to pits and oxen, Talmudic philosophical principles can be extracted. In the specific case of the principle of panim hadashot, the sanctification of the commonplace, the elevation of the ordinary is brought to the forefront. Through the examination of what defines a keli, and when it becomes something different than it was before, the metaphysical questions of identity obtain their meaning and objects obtain their value.[xix]

This metaphysical underpinning to the Talmud is best exemplified by one of the most famous aggadot, that of the tannur shel Akhnai.[xx] The oven in the story, instead of having been made into one whole, was made from separate tiles with a layer of sand between each to connect them.  R. Eliezer said that the oven cannot acquire tum’ah since each tile on its own was just a portion and not a keli, the layer of sand between each tile prevents the tiles from becoming one united keli. The Sages, however, held that the outer layer of cement unites all the tiles into one keli, and thus it is capable of acquiring tum’ah. [xxi] R. Eliezer then attempts to prove the veracity of his judgment through all kinds of miraculous means, even calling upon a Heavenly Voice to agree with him. R. Yehoshua rejects even this proof because “[the matter] is not in heaven […and] after the majority must one incline.”[xxii]

Many interpretations of the symbolic meaning of the case exist. These include issues of fragmentation versus unification of rabbinic opinion and ruling,[xxiii] as well as a debate surrounding the persecution of the Jews in Jerusalem.[xxiv] It is possible, however, to read this case in light of the prior metaphysical discussion.  Immanuel Kant was the first to outline the differences between reality as it actually exists, the noumena, and man’s perception of reality, the phenomena.[xxv] Man, according to Kant, has specific categories, such as time and space, which he imposes upon reality so that his mind can comprehend it. The crux of R. Yehoshua’s assertion, that Torah laws are subject to man’s view of how they should be rather than God’s, seems to correspond to Kant’s distinction. God, who is Omniscient, can “experience” the noumena, whereas man is limited to what his mind can grasp. As such, halakhic principles should be based upon what the majority of men experience, not what God experiences.

The overt discussion of metaphysics in the story of tannur shel Akhnai surrounds the laws of impurity. The laws of impurity, as discussed in this article, represent a constant reminder of the sanctification of commonplace, ordinary objects.  They represent the metaphysical bridge between man’s phenomena, the principles such as panim hadashot he uses to determine the law, and God’s noumena, the overarching concept of tum’ah and taharah that has no physical bearing on reality. It is through this bridge that objects gain meaning and metaphysical questions begin to acquire significance.

Theophrastus, a Greek philosopher, described the Jews as a “nation of philosophers.”[xxvi] The Rabbis of the Talmud, who lived approximately 800 years after Theophrastus, continued this tradition not only in their didactic stories but covertly in the legal system and rulings they established. A comprehensive study of the halakhic system for metaphysical indications could yield both a better understanding of the reasoning for specific halakhic concepts, as well as a Talmudic response to the metaphysical questions that have plagued philosophers since ancient times.

Dani Lent is a senior at SCW majoring in Biochemistry and is a Staff Writer for Kol Hamevaser.


[i] Peter van Inwagen. Metaphysics (Boulder, CO: Westview Press, 2009), p. 4.

[ii] Yerushalmi Rosh Hashanah 3:5.

[iii] I thank Dr. David Shatz for first introducing me to this field and for sparking my interest in the specific topic of the role of metaphysics in the Talmud in his “Metaphysics” class.

[iv] Van Inwagen, p. 24.

[v] Thomas Hobbes. “Concerning Body,” In Mary Whiton Calkins (ed.), The Metaphysical System of Thomas Hobbes in Twelve Chapters. (Chicago: The Open Court Pub. Comp., 1912), p. 85.

[vi] This argument, as well as many of the Talmudic examples and understandings drawn upon in this article are credited to the following article: Eli Hirsh. “Identity in the Talmud,” Midwest Studies in Philosophy 23,1 1999:. 166-180.

[vii] Midras tum’ah is the impurity a utensil contracts from supporting people who have specific levels of impurity. Magga midras tum’ah is the impurity contracted from coming in contact with a utensil that is impure with midras tum’ah. Explanations obtained from: Yoseph Shechter. A Lexicon of the Talmud. (Tel Aviv: Dvir Publishing House, 1990.

[viii] Shabbat 112b. (Soncino English Translation.)

[ix] Kelim 17:1.

[x] If this Mishnah is extrapolated to the case of Theseus’s ship, it would seem that the ship is no longer Theseus’s original ship from the point at which enough planks are removed and then repaired so that the patch represents a substantial portion of the ship, in the same way that a hole large enough for a pomegranate would represent a substantial portion of a standard wooden dish.

[xi] This understanding of the status of a keli, that it must have a function independent of other things, is based on the Hazon Ish’s comments to Kelim 31:2.

[xii] Tosafot to Shabbat 112b, s.v. aval.

[xiii] Hirsh, p. 175.

[xiv] Kelim 28:5.

[xv] Shabbat 58a-58b.

[xvi] Hirsh, p. 169.

[xvii] Hobbes,  p. 84.

[xviii] Joseph B. Soloveitchik, Halakhic Man, trans. Lawrence Kaplan (Philadelphia: Jewish Publication Society of America, 1983), p. 24.

[xix] Hirsh, p. 176.

[xx] Bava Metsi’a 59a-59b.

[xxi] This explanation of the debate is based on Rambam’s commentary to Kelim 5:10.

[xxii] Bava Metsi’a 59b.

[xxiii] Jason P. Rosenblatt and Joseph C. Sitterson, Jr. (eds.), “Not in Heaven: Coherence and Complexity in Biblical Narrative. ed. by (Bloomington, IN: Indiana University Press, 1991), pp. 2-4.

[xxiv] Joseph Elijah Henkin, Kitvei ha-Gaon Rabbi Yosef Eliyyahu Henkin, Zts”l, vol. 2, ed. Avraham Yitshak Zeshoravel  (New York: Ezrat Torah, 1989), pp. 211-214.

[xxv] Immanuel Kant. “Analytic of Principles” Critique of Pure Reason, transl. J. M. D. Meiklejohn (London: Henry G. Bohn, 1855), pp. 180-187.

[xxvi] Quoted in Hyam Maccoby,. The Philosophy of the Talmud. (London: Routledge Curzon, 2002), pp. 10.