Mishnah/Seder Nezikin/Tractate Bava Kamma/Chapter 1/1
ארבעה אבות נזיקין השור והבור והמבעה וההבער לא הרי השור כהרי המבעה ולא הרי המבעה כהרי השור ולא זה וזה שיש בהן רוח חיים כהרי האש שאין בו רוח חיים ולא זה וזה שדרכן לילך ולהזיק כהרי הבור שאין דרכו לילך ולהזיק הצד השוה שבהן שדרכן להזיק ושמירתן עליך וכשהזיק חב המזיק לשלם תשלומי נזק במיטב הארץ.
There are four generative categories of causation in property torts: The ox, the pit, the "consumer," and the conflagration.
The characteristics of the ox are not similar to the characteristics of the "consumer."
And the characteristics of the "consumer" are not similar to the characteristics of the ox.
Nor are either of these, which have an animating spirit, similar to the conflagration, which has no animating spirit.
Nor are any of these, which are wont to move and do damage, similar to the pit, which is not wont to move and do damage.
The common denominator among them is that they are inclined to do damage, and the duty of their care is upon you, and if they do damage, the defendant must pay from the best land.
"Four generative categories of causation in property torts"- There are four paradigmatic cases in Exodus 21-22 whose circumstances provide the basic factual elements for establishing the defendant's responsibility for duty of care (Heb., "shemirah") and causation of damage (Heb., "hekhsher nezeq") under Rabbinic law. Each of the categories is applied to matching circumstances in particular cases to determine the extent of the defendant's liability for damages. From these four generative categories, and their general characteristics, one may derive all other possible causes of property damage by analogy.
"The ox"- It gores using its horns. See Exodus 21:35-36. Note that this case is restricted to property damage-- whether destruction of livestock or produce-- as are all of these paradigmatic biblical cases. Personal damage will be addressed by the Mishnah in Bava Qamma, chapter 8.
"The pit"- An open hole made by the defendant in a public thoroughfare. See Exodus 21:33.
"The consumer"- The translation of this word is intentionally vague. In the original the word is "ha-mav'eh." This an unusual word and most likely is a loan from Aramaic. In its Aramaic context it usually refers to the catastrophic consumption of property, often by fire. Here, it is introduced by the Mishnah to refer to the unwarranted destruction of a plaintiff's produce by a defendant's livestock, either by eating it (a further sub-category, "the tooth"), or treading on it ("the leg").
"The conflagration"- A fire that a defendant lit, which then burned out of control, causing damage. Both this category and the previous one are derived from Exodus 22:4.
"The characteristics of the ox..."- Exodus 21 distinguishes between a tame ox (Heb., tam) and one that has shown an inclination to attack (Heb., mu'ad), assigning a higher level of liability in the latter case. This is not the case with "the tooth" or "the leg", which describe the natural inclinations of all animals.
"An animating spirit"- I.e., they are animals possessed of an independent will and therefore command a higher level of duty of care on the part of the defendant.
"Wont to move and do damage"- They may do their damage while traversing a large area, unlike the pit, which does its damage in a single spot.
"From the best land"- If the defendant fulfills the court's judgement with a grant of land, the land he or she transfers to the defendant must be land of the highest agricultural quality.