Living among friends is something that has many benefits, yet at the same time, it can present challenges too. One of the most common questions, if not the most common of all, that comes up in dorms and other close knit living arrangements is the question of using something that belongs to a friend without permission. We have all been in this situation: a bag of potato chips, an interesting book, or something as simple as a can opener, that belongs to a friend, who, however close he may be, happens to not be there at the time you need to use it. The burning questions becomes, to use or not to use? Should I assume that since my friend would definitely give me permission, I can use it; or, since I did not receive explicit permission, I can’t use it.

Needless to say, this is only a question if it is clear and obvious that the owner would grant permission to use the desired item. If there is any doubt about that, it would be surely prohibited to use the object, just as using anything against a person’s will is the equivalent of theft.

On the one hand, it would seem obvious that using something under such circumstances should be absolutely permitted. The principle of umdena tells us that we may rely on any iron-clad assumption. Hence, in this case we should rely on the assumption that the person permits us to use his property, without any more concrete evidence.

At the same time, we have the conflicting principle of ye’ush shelo midaat. This principle tells us that despite the permission to take something whose owner gave up on, if the owner does not know that the object is lost, one may not take that object. If, for example, there is permission to take something that was swept away into the sea because the owner must have given up on it, nevertheless, if that same owner does not know that his object was swept away by the sea, one may not take it. Even if we know with certainty that had the owner known about this misfortune he would have certainly given up hope on his item. Following this logic, clearly, even if one knows that their friend would permit the use of a belonging, he may not use it until such permission and acknowledgement are granted.

In a widely known and revolutionary ruling (CM 358:1), Rabbi Shabtai Cohen, also known as the Shach, takes a different position on this matter and permits using another person’s objects, even without the knowledge or consent of the owner, as long as we can be sure that had the owner known, he would have permitted the desired use. There is a distinction between this case and the case of the lost object, argues the Shach. In the case of borrowing, the latent permission can be assumed from the first moment the object is being used. In the case of a lost item, on the other hand, the rightful owner of the object never intended for the object to end up in the finder’s hands. That being the case, the finder should not have picked it up to begin with. When the finder finds the lost object, the owner still has his hopes fixed on finding and possessing that object. When the borrowed item is being used, the potential permission is already in place. Had the owner just known about this, he would grant his explicit permission, in which case the usage is permitted from the first moment the item was taken.1

This fundamental explanation contains a profound conceptual understanding. When a person has an object, they take into consideration different possibilities. The possibility that someone else might want to use it has been taken into consideration by the owner, and that possibility is one that the owner entertained and agreed to-consciously or subconsciously.  If however, a person’s item was swept away by the sea, or other highly unexpected misfortune, one cannot assume the owner’s mental acknowledgment, as this option was not part of the owner’s schema of things; in no way did the owner grant permission.

There is a great deal of discussion about how to understand thisShach. Some argue the Shach means to say that there is a distinction between usage and transfer of ownership. If one is just going to use another person’s object, then latent permission may be relied on. If, however, one wants to transfer ownership, like in the case of a found object, then one cannot rely on latent concession, and needs to have an active, and conscious consent. Others, however, take the position that this Shach means that even in a case when ownership is being completely transferred, one may rely on the latent and precognitive permission from the owner. Moreover, there are those who disagree entirely with the Shach’s unique approach to the matter. 2

Practically speaking, may one rely on this position of the Shach? Rabbi S.Z. Auerbach3 takes the position that one may rely on the position of the Shach only in a case in which the item being used is not being consumed: when using a hammer, a book, and the like. In the case of food, drinks, and other items that get consumed in a non-replaceable way, one may not rely on theShach.

Not taking the position of the Shach, however, does not exclude any use of something that belongs to another with no explicit permission. There are several clear examples in which one is permitted to make use of something without permission. If a person wants to take something from someone that is so small that no one in that place would mind if it is taken from them, such as taking a small piece of wood for a toothpick from a tree, or a small straw from a cart, one may take it, unless he knows that the owner would be upset or unless the owner is available and can grant explicit permission. 4

Another example of being able to take something without explicit permission is if one will be using the object for the sake of fulfilling a mitzvah. For example, if one did not don tefillin yet or shake a lulav and etrog he may use these items without explicit permission from the owner. The logic underlying these two examples is that even if one does not rely on presumed permission, one can be certain that the owner consents to his object being used for mitzvah. This is not the same as the Shach’s case; here the owner’s conscious consent was given before the use. The moment he put down the object we assume that he consciously assented to others using it for a mitzvah. 

Respecting the ownership and rights of each and every individual to their property is the epicenter and foundation of any civil society. Being able to do so while finding common ground for cooperation, generosity, and mutual agreement makes society all the more successful and prosperous.

1 Shach’s opinion goes against the position of the Tosafot (Bava Metzia 22a s.v. Mar), Hagahot Osheri (ibid, siman 3) and the Hagahot Mordechai (ibid, letter 424). Of the Achronim noted for taking a position that strongly prohibits any unauthorized use — in opposition to the Shach — is Rabbi S.Z. of Liadi (SA Harav Hilkhot Metzia 1).

2 See She’elot U’teshuvot Oneg Yom Tov 111 and a diametrically opposite position in Birkat Shmuel (Bava Metzia Siman 21:5). See also Ktzot Hachoshen, 262:1 and Netivot Hamishpat 195:1. Cf. Rabbi Eliezer Y. Waldinburg, Tzitz Eliezer,  Vol 10, siman 39:6.

3 Quoted in Halichot Shlomo, Hilchot Tefillah, chapter 19 footnote 13.

4 Aruch Hashulachan (CM 359:1)

Published in the YU Lamdan, March 29th 2015