Beitzah 39

Who owns a public good?

Today we continue our discussion of the permitted range of motion for various items on Shabbat and the festivals by looking at a new kind of item: water! As a reminder, we’ve seen that the Talmud uses the expression “as the feet of X” to associate an object or animal with a specific person and their specific 2000 cubit range of motion on Shabbat and festivals. The mishnah on our page teaches:

A cistern of an individual, water drawn from it is as the feet of the individual.

And water drawn from a cistern belonging jointly to all the people of a particular town is as the feet of the people of that town.

And water drawn from a cistern of those who come up to the land of Israel from Babylonia (i.e., a public cistern) is as the feet of whoever fills it.

The first two cases that the mishnah offers tell us that the permitted range of motion for the water in a cistern is tied to the location of the cistern’s owners, whether it be an individual or a community. The third case is somewhat different. Here the water source is a public good, available to locals and travelers. In this case, there is no owner to serve as the anchor for our calculation about the water’s permitted range of travel and instead the math centers on whoever draws the water for their own use. 

The Gemara raises a question about this third case. Everyone agrees that if one draws water from a public cistern for themselves, they serve as the anchor — the water can travel as far as they can. But what if they are drawing water for someone else? Is the person drawing the water or the intended recipient the anchor?

Rav Nahman said: The water is as the feet of the one for whom they were filled. Rav Sheshet said: It is as the feet of the one who filled it.

Rav Sheshet says we calculate the water’s permissible range of motion according to the one who draws it; Rav Nahman says we calculate according to the one who receives the drawn water. What is at the heart of Rav Nahman and Rav Sheshet’s disagreement? The Gemara suggests that these two rabbis dispute how we understand the “public” nature of a public cistern:

One sage (Rav Sheshet) holds that a public cistern is ownerless.

And one sage, Rav Nahmanholds that a public cistern is considered jointly owned by all its partners.

If a public cistern is ownerless, whoever takes possession of the water first becomes its new owner immediately. Therefore, we would calculate the range of motion based on that new owner — the water drawer. If, however, a public cistern is owned by everyone, then everyone is already a partner in the item and one partner can take some of it for another, the intended recipient. 

On the one hand, this discussion seems like a very theoretical dispute on the nature of public goods. Are they owned by no one or everyone? On the other hand, we see that this theoretical dispute has real practical implications for travelers who are on the road during Shabbat and festivals. After all, water is a necessity; Jewish travelers would absolutely need to know how far they can travel with the water that they’ve drawn.

So which rabbi is right? The Gemara doesn’t tell us on today’s daf. I’ll be honest — I was rooting for Rav Nahman. Cisterns are not naturally occurring sources of flowing water. They are filled by rain or, when rains are few, by hand. And if no one owns it, no one is likely to take responsibility for it being filled, clean, or safe. So I prefer the interpretation that they are jointly owned. But both the medieval Maimonides (Mishneh Torah, Rest on a Holiday 5:14) and the 16th century law code the Shulchan Aruch (Orach Chayim 397:16) side with Rav Sheshet — public goods are owned by no one. Perhaps, in their minds, this is what makes them truly public.

Read all of Beitzah 39 on Sefaria.

This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on October 9th, 2021. If you are interested in receiving the newsletter, sign up here.

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