What is the organizing principle of the first Mishna? TB Baba Kama 2-4

Two days ago this past Shabbat, we began massekhet Baba Kama. It is the first massekhet in Seder Nezikin. Originally this massekhet was called massekhet Nezekin, the tractate of damages. Because it was extremely long, the rabbis divided it into three separate massekhtot, Baba Kama (the First Gate), Baba Metzia (the Middle Gate), and Baba Batra (the Last Gate).

The first mishna lists for primary categories of damages. “There are four primary categories of damage: The category of Ox (הַשּׁוֹר); and the category of Pit (הַבּוֹר); and the category of Maveh (הַמַּבְעֶה), and the category of Fire (הַהֶבְעֵר).” Of the four terms, the third, Maveh (הַמַּבְעֶה) is the most uncommon and unusual. Perhaps the reason why the Mishnah uses such an unusual and uncommon word was stylistic. In Hebrew ox-shor rhymes with pit -bor and  maveh kinda sounds like hevair making the mishna easier to memorize.

Because Maveh is an uncommon and unusual word, Rav and Shmuel disagree what it means and each has a different organizing principle of the mishna. “Shmuel, who says: Maveh, this is the category of Eating (שֵׁן) (the animal grazes on another person’s property)… Rav, says: Maveh, this is the primary category of Man, which includes damage caused by a person, not by his property or animal.”

Property damage is Shmuel’s organizing principle, that is, my property damages your property. My ox, my pit, and my fire cause damages to your property. He divides the ox into two major categories. They are significantly different from each other. The damages of an ox e.g goring is unusual and the ox does not derive any benefit from this damage. The damages of an ox eating is quite common and either the ox drives benefit from the food it eats or the owner of the ox derives benefit for he saves money by not having to feed his ox.

Four different causes of damages is Rav’s organizing principle. Obviously an ox is an animal that causes damages. A human being is the next category and is different from an animal for a human being is always forewarned and liable for his actions. A pit is an inanimate object which does not moves one place to another. Although fire is also an inanimate object, an outside force of the wind is needed to blow the sparks to another person’s field to cause the damage. In other words unlike the pit, the fire spreads.