4 levels of shemira TB Baba Kama 45

Obviously if a person guards his ox appropriately, he is not held liable for damages. But what is that appropriate level of guarding? Although we have discussed the different levels of guarding (shemira-שְׁמִירָה) previously, daf TB Baba Kama 45 delineates four levels of shemira.

1.    “If the ox’s owner tied it with reins to a fence or locked the gate before it in an appropriate manner, but nevertheless the ox emerged and caused damage, whether the ox is innocuous (tam)  or forewarned (muad), the owner is liable, since this is not considered sufficient precaution to prevent damage; this is the statement of Rabbi Meir.” (Sefaria.org translation) The pen’s fence is not strong enough to withstand a stiff wind.  This shemira is called a reduced level of shemira (shemira pekhuta- שְׁמִירָה פְּחוּתָה). Consequently, both the tam and the muad need superior level of shemira (shemira me’ula-שְׁמִירָה מְעוּלָּה)

2.    “Rabbi Yehuda says that if the ox is innocuous the owner is liable even if he safeguarded it appropriately, since the Torah does not limit the required safeguarding for an innocuous ox. But if the ox is forewarned, the owner is exempt from paying compensation for damage, as it is stated in the verse describing damage by a forewarned ox: “And the owner has not secured it” (Exodus 21:36), and this ox that was tied with reins or behind a locked gate was secured.” (Sefaria.org translation) Rabbi Yehuda’s position is the most difficult to understand logically. Rabbi Yehuda understands that the tam’s starting point is shemira pekhuta. Since the owner of the tam still needs to pay for damages occurred with shemira pekhuta, he needs shemira me’ula to avoid damage liability. One principle that expounds the Torah is “one amplification following another amplification, and the principle is that an amplification following an amplification  is stated only in order to restrict its extent.( וְאֵין רִיבּוּי אַחַר רִיבּוּי אֶלָּא לְמַעֵט)” (Sefaria.org translation) Because the muad already begins at the level of shemira me’ula, the verse “And the owner has not secured it,” comes as the second amplification which has the effect of restricting is extent. Consequently, the muad only needs shemira pekhuta.

3.    “Rabbi Eliezer ben Ya’akov says: In the cases of both an innocuous ox and a forewarned ox in which its owner provided reduced safeguarding, he is exempt from liability.” (Sefaria.org translation)

4.    “Rabbi Eliezer says: An ox (muad-gg) has no sufficient safeguarding at all other than slaughtering it with a knife; there is no degree of safeguarding that exempts the ox’s owner from liability.”