Pesik reisha
Encyclopedia
In Halacha a pesik reisha (Lit. cutting off the head) is a permitted action which will definitely cause as a side effect
an action that would be forbidden. The classical case of a Pesik reisha found in the Talmud
is cutting the head off of a chicken on Shabbos (the Jewish Sabbath) in order to keep the head.
The acquiring of the head is permitted but the necessary killing of the chicken is prohibited. A practical case of pesik reisha is the dragging of a heavy chair over soft earth which will definitely result in furrows which constitute the melacha (action) of plowing. As a result, it is forbidden according to Halacha for a Jew to drag a chair over soft earth on Shabbos, which will necessarily result in the creation of furrows (one of the 39 melachot)
The phrase is short for pesik reisha velo yomus? - Will you cut off its head and it will not die? This refers to somebody who cuts off the head of a chicken so that his child can play with it. (Evidently in the time of the Talmud
it was common for children to play with chicken heads.) Even though he did not particularly want the chicken to die, since that was the only way he could get the chicken's head, he is considered to have intentionally killed the chicken. As such it would be forbidden to do on Shabbos.
There is great literature and discussion amongst the Acharonim
in this matter, especially in the Brisker
school of Torah-study.
Unintended consequence
In the social sciences, unintended consequences are outcomes that are not the outcomes intended by a purposeful action. The concept has long existed but was named and popularised in the 20th century by American sociologist Robert K. Merton...
an action that would be forbidden. The classical case of a Pesik reisha found in the Talmud
Talmud
The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....
is cutting the head off of a chicken on Shabbos (the Jewish Sabbath) in order to keep the head.
The acquiring of the head is permitted but the necessary killing of the chicken is prohibited. A practical case of pesik reisha is the dragging of a heavy chair over soft earth which will definitely result in furrows which constitute the melacha (action) of plowing. As a result, it is forbidden according to Halacha for a Jew to drag a chair over soft earth on Shabbos, which will necessarily result in the creation of furrows (one of the 39 melachot)
The phrase is short for pesik reisha velo yomus? - Will you cut off its head and it will not die? This refers to somebody who cuts off the head of a chicken so that his child can play with it. (Evidently in the time of the Talmud
Talmud
The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....
it was common for children to play with chicken heads.) Even though he did not particularly want the chicken to die, since that was the only way he could get the chicken's head, he is considered to have intentionally killed the chicken. As such it would be forbidden to do on Shabbos.
There is great literature and discussion amongst the Acharonim
Acharonim
Acharonim is a term used in Jewish law and history, to signify the leading rabbis and poskim living from roughly the 16th century to the present....
in this matter, especially in the Brisker
Brisker
Brisker is Rabbinic name and Jewish surname of:* Rev Chaim Brisker , a rabbi and Talmudist** Brisk tradition and Soloveitchik dynasty...
school of Torah-study.