Melechet Machshevet

Melacha sheina tzaricha legufa: There is a major dispute as to the definition of melacha sheina tzaricha legufa. Tosfot (94a s.v Rabbi) explains that melacha sheina tzaricha legufa is a requirement that the purpose of each melacha be similar to the purpose for which it was done in the Mishkan. For example, if a person carries, he would be culpable if he carries in order to transport the object from one place to another. However, if he carries it just to remove it from a location that is melacha sheina tzaricha legufa.

Rashi (93b s.v. VeRabbi) writes that a melacha she’eina tzaricha legufa is accomplished when one performs an action in order to prevent a destructive outcome. It is possible to explain Rashi’s opinion as follows: If a person does an activity which is completely destructive it is considered mekalkel and if it is completely constructive it is a melacha. However, if the act is done to rectify a situation so that a negative outcome doesn’t continue to occur, that is considered a melacha sheina tzaricha legufa. The Ramban (Shabbos 106a s.v. veein ani) presents an alternate approach. He says that melacha sheina tzaricha legufa is an action done for no purpose at all with regards to the object upon which the melacha occurs. However, if the action is done for the purpose or needs of the object upon which the melacha is occurring, it is tzaricha legufa even if it is destructive. For example, the Ramban considers performing Milah on Shabbos to be tzaricha legufa since it is for the benefit of the person receiving the Milah.

When an action is melacha sheina tzaricha legufa, there is a dispute between Rabbi Yehuda and Rabbi Shimon whether this is a biblical prohibition or only rabbinic. Although the Rambam holds like Rabbi Yehuda, the halacha follows Rabbi Shimon and assumes that it is only rabbinic.

Dvar sheina mitchaven: Doing a permitted action in a way in which one doesn’t intend for a melacha to occur as a byproduct of one’s intended action is considered a dvar sheina mitchaven. Nonetheless, when it is inevitable that a melacha will take place as a result of one’s inherently permissible action, that action becomes forbidden (see Pesik Reisha). For example, dragging a light chair in a field where one’s intent is to transport the chair would be a dvar sheina mitchaven when the furrow is created as one did not intend to create a furrow. Tosfot (Shabbos 75a s.v. mitasek) writes that dvar sheina mitchaven is not unique to Shabbos; rather, it is a general exemption found in numerous laws throughout the Torah.

There is a dispute between Rabbi Yehuda and Rabbi Shimon whether performing an action that is a dvar sheina mitchaven is permitted or forbidden. Within the opinion that is forbidden, many assume that it is only a rabbinic prohibition on Shabbos. The halacha is that a dvar sheina mitchaven is completely permitted.

Pesik Reisha: If a person does a permitted action that has an inevitable unintended result that is forbidden, it is considered a pesik reisha. Although Abaye originally believed that it is was permitted in accordance with Rabbi Shimon, later he agreed with Rava that it forbidden. The halacha follows Abaye and Rava. Nonetheless, there is a dispute amongst the Rishonim whether a Psik Reisha is forbidden on a biblical or rabbinical level.

Of noteworthy mention is the opinion of the Aruch (s.v. svar n. 5), who holds that a pesik reisha is permitted if it done in a way that doesn’t benefit the one performing the action. Some have explained that his opinion is based on the understanding that pesik reisha is forbidden because it is as though one actually intended for the forbidden result to occur, being that it was inevitable and foreseeable. However, if one doesn’t benefit from the forbidden result, even if it is inevitable, clearly it is unintended since one doesn’t benefit. On the other hand, Tosfot (Shabbos 103a s.v. lo) argues that pesik reisha is forbidden under all circumstances. According to Tosfot, perhaps pesik reisha is forbidden because the forbidden result is considered included in one’s original permitted action since it is inevitable. That being the case, even if one doesn’t benefit, the forbidden action is considered included in one’s permitted act.

Mitasek: Doing an action in a mitasek manner is to do something forbidden without intent that one is doing a forbidden action. For example, if one takes a vegetable lying on the ground thinking that it is detached from the ground but in reality it is attached, it would be considered mitasek. That is a case in which one’s intent was to do a permitted action and in reality a forbidden one resulted. The second area included in mitasek is where one has intent for a forbidden action but doesn’t believe that it will come out the same way that it really does. For example, if a person intends to take a red apple off a tree and ends up taking a green apple assuming that a person is concerned about the color of the apple, then that would be considered mitasek. Tosfot Shabbos 72b s.v. nitchaven adds that this second category of mitasek is unique to Shabbos. Whereas the first category is universal, the second is a leniency based on the concept of melechet machshevet.

A person who does an action that is mitasek is certainly not chayav a korban. However, there is a dispute whether someone who is mitasek did not violate any prohibition or perhaps he has violated a biblical prohibition. With regards to Shabbos specifically, everyone agrees that there is no biblical prohibition for doing an action in a mitasek manner.

Shinui: If a person does a melacha in an abnormal fashion, he isn’t culpable for his action. Nonetheless, normally such an action would be a rabbinic prohibition. In certain cases, an extreme abnormality might not be prohibited at all.

Mekalkel: The Torah prohibited melacha when it is done in a constructive manner. If, however, one does a melacha in a destructive fashion, there is no biblical prohibition. For example, a person who digs a hole in a field that isn’t meant to be plowed in order to use the dirt isn’t culpable because his action was destructive.

There is a major dispute to what extent one needs to have constructive element to one’s action when performing an intrinsically destructive melacha, such as extracting blood from a living being or lighting a fire. Some assume that there’s no need for a constructive outcome when performing such melachot. On the other hand, perhaps these melachot are like every other melacha require a constructive element. Another alternative is that a minimal amount of constructive purpose is required in order to be culpable.

Shnayim She’asauha: If two people do a melacha together each person is exempt and isn’t considered as though he violated the melacha independently. There is a dispute between Rabbi Yehuda and Rabbi Shimon whether this applies only if each person couldn’t have independently done the melacha or even if the melacha truly required two people . While the halacha is that shnayim she’asauha isn’t required to bring a chatat there is a dispute whether the prohibition to do a melacha with someone else’s help is rabbinic or biblical.

Grama: One who performs a melacha indirectly isn’t culpable and many Rishonim assume that it is totally permitted. There is a dispute as to what is considered indirectly in order to exempt one from melacha. Some say that any action which will cause a melacha to occur at a later point is considered grama. Others explain that an action is only considered grama if it is disconnected physically and temporally from the process that eventually causes the melacha to occur.