Bava Kamma, Chapter 1, Mishnah 4. The subject of this Mishnah is the distinction between an animal that causes damage under the category of a 'tam' and an animal that causes damage under the category of a 'mu'ad'. These two terms are difficult to translate simply, as they are technical legal terms that refer to the consequences and the extent of liability in the event that damage is caused.
The Terms Tam and Mu'ad:
Tam - This does not involve a foreseeable event. The owner did not have an increased duty of care, since domesticated animals are not expected to cause damage intentionally - what we referred to as the primary category of Keren. Therefore, the owner's liability is limited: payment of only half the damage, and even this amount is capped at a ceiling, which is the value of the animal that caused the damage.
Mu'ad - The damager must pay for full damage and compensate the victim for his entire loss, without limitation. And if the payment is made from property - 'min ha'aliyah', meaning from his best assets.
In terms of literal meaning: "Tam" signifies simplicity and lack of complexity, and hence one cannot expect a domesticated animal to go and cause damage intentionally. "Mu'ad" - The closest translation is someone who has received a warning, or someone who has been officially notified.
The origin of the term is in a verse in Parashat Mishpatim (Exodus 21:29): "But if the ox was prone to gore previously, and its owner was warned, and he did not guard it." The word "vehu'ad" (was warned) is in the passive huf'al form, meaning that the owners received a warning to be careful, after the ox had gored three times, establishing that this ox is a gorer. The consequence is liability for full damage, hence the title 'shor hamu'ad' (the forewarned ox).
The root of the word is derived from 'ed' (witness) and 'edut' (testimony), as we find in Genesis (43:3): Jacob asks Judah to return to Egypt and bring food, and Judah replies that they cannot return unless they bring Benjamin with them, since "the man strictly warned us" - Joseph, who was considered in their eyes to be Pharaoh's right-hand man, had already cautioned them and warned them in advance. Hence 'mu'ad': one who has been officially warned. In any case, there is not much point in translating the term; it is a technical term meaning full damage and full compensation, as opposed to 'tam' which means half damage.
The Mishnah here deals exclusively with animals. It does not discuss primary categories of damage such as Bor and Esh, for which we have already said that one pays full damage, but rather the question of when the animal is a tam and when it is a mu'ad. As the Mishnah states: "Chamishah tamin vachamishah mu'adin" - Five categories in which a domesticated animal is classified as a tam, and five categories in which it is classified as a mu'ad.
Five Tamin:
The Mishnah opens: "Habehemah einah mu'edet" - It is not expected to cause damage in the following ways, and therefore the payment is half damage:
"Lo ligach" - To gore with its horns.
"Velo ligof" - To push with its body.
"Velo lishoch" - To bite.
"Velo lirbotz" - Crouching down, meaning that the animal lies down on an object to crush it. This is different from an animal that lies down out of fatigue, which is not Keren but Regel, as this is the normal behavior of cows.
"Velo livot" - To kick.
Each of these five actions is considered unusual behavior, and therefore the animal is a tam regarding them and the payment is half damage.
Five Mu'adin:
On the other hand, in the following five cases the animal is considered forewarned, and the result is liability for full damages:
"Hashen muedes le'echol es hara'uy lah" - 'Tooth' is one of the primary categories of damage, involving an animal deriving benefit for itself. It is expected that it will eat the type of food fitting for it: if your cow eats my grass, this is an expected occurrence and is considered 'tooth' damage. However, if it ate my shirt or bit my finger, this is not 'tooth' at all but rather 'horn', as we mentioned regarding "to bite", since it is not normal for cows to eat shirts and fingers.
"Veharegel muedes leshaber bederech hiluchah" - 'Foot' is a technical term for an animal that causes damage during its normal walking and under regular circumstances, and therefore it is expected that it will break things in its path.
"Vehashor hamu'ad" - An ox that has been established as dangerous: it gored, kicked, or bit three times and the owner was warned about it. From now on, it is a 'forewarned ox', for which one pays full damages.
"Vehashor hamazik birshus hanizak" - A completely different matter: an ox that caused damage neither in its owner's property nor in the public domain, but in the private property of the injured party. For example, your cow entered my backyard and started kicking my sheep. Generally, a cow kicking sheep is an unusual act and it is classified as innocuous, but since this happened on my private property, a place where your cow has no business being, the owner is automatically liable for full damages as if it were forewarned. 'Forewarned' here is simply a technical term meaning full payment.
"Veha'adam" - A person is always considered forewarned. A person is always responsible for his actions, and if he caused damage - even accidentally, and even while he was asleep - it makes no difference. It is incumbent upon every person to guard himself and his body, and if his body damaged someone else's property, he pays full damages right from the start.
It is worth noting here that the fourth category is subject to a dispute brought in the next chapter, between Rabbi Tarfon and the Sages. Our Mishnah follows the view of Rabbi Tarfon, who holds this exceptional law: that even with 'horn', if the damage occurred in the private property of the injured party, the damager - the owner of the cow - is liable for full payment right from the first time. However, the halachah does not follow his view, but rather the words of the Sages, and therefore this category is not the accepted halachah.
Animals That Are Forewarned From the Start:
Now the Mishnah introduces a new subject, which should not be confused with the previous one: with domesticated animals - cows, goats, sheep, camels, and donkeys - we do not expect them to cause damage intentionally. But there are animals that are inherently dangerous, and the Mishnah lists six of them: "Hazeev veha'ari vehadov vehanamer vehabardelas vehanachash - harei elu muadin" - the wolf, the lion, the bear, the leopard, the bardelas, and the snake are forewarned.
It should be noted that the word 'bardelas' in modern Hebrew means a cheetah, but this is not its meaning in our Mishnah. The Bartenura, and similarly the Rambam, explain that a bardelas is a hyena. In the Land of Israel, there are hyenas but not cheetahs, and therefore the appropriate translation is a hyena.
The meaning of this is: these animals are always dangerous. Someone who keeps a lion as a pet must anticipate the danger in advance. This is not like a cow, which does not intend to cause harm; lions bite and prey.
"Rabbi Eliezer omer, bizman shehen bnei tarbus - einan muadin, vehanachash mu'ad le'olam" - According to Rabbi Eliezer, when dealing with trained and domesticated animals, such as someone who raised a trained bear in his home to serve as a pet, he does not have to expect it to lash out and attack, since this bear is well-trained. However, Rabbi Eliezer admits that training does not work on the brains of reptiles: there is no such thing as a pet snake that does not bite, and it is impossible to train this animal not to bite. The more intelligent mammals, says Rabbi Eliezer, can be trained not to bite, and therefore a trained wolf, lion, bear, leopard, and hyena are classified as innocuous from the start, and one does not pay full damages for them.
The halachah does not follow Rabbi Eliezer, but rather the Tanna Kamma - the Sages - who hold that these animals are always dangerous, and one who keeps them as a pet bears full responsibility from the start, no matter what.
The Difference Between Innocuous and Forewarned:
Finally, the Mishnah clarifies the halachic implications - the practical differences - between that which is classified as innocuous and that which is classified as forewarned, and it lists two differences: "Ela shehatam meshalem chatzi nezek migufo, vehamu'ad meshalem nezek shalem min ha'aliyah" - except that the innocuous animal pays half damages from its own body, and the forewarned animal pays full damages from premium property.
"Chatzi nezek" - The compensation amount that the owner of the innocuous animal pays to the injured party is only half the damage.
"Migufo" - Literally, the payment comes from the body of the damaging animal; and conceptually, this is a limited liability with a ceiling of the animal's value.
For example: My cow entered your courtyard and began to trample your sheep, and the total damage it caused is one hundred thousand dollars. The maximum I will be obligated to pay is half the damage - fifty thousand dollars. However, if my cow is worth only one hundred dollars, even though my obligation stands at fifty thousand, I can say: Take the cow or its value, one hundred dollars, and that is the ceiling. This is the concept of paying half damage from its body.
And regarding a Mu'ad: "Meshalem nezek shalem min ha'aliyah" - it pays full damage from the best property. If I was warned again and again, and this is the fourth time my cow enters your courtyard and tramples your sheep, I must now pay the full damage - the entire one hundred thousand dollars that it caused. "Min ha'aliyah" literally means from the best: If I pay you with land rather than cash, I must give you from my highest quality land, and I cannot give you from my inferior land.