If one is walking with a [ceramic] jug, and another with a [wood] beam, and this one’s jug breaks on that one’s beam, he [the beam holder] is exempt [from paying damages], because this one has the right to move, and that one has the right to move. If the beam-bearer was in front, and the jug-bearer behind him, and the jug breaks on the beam, the beam bearer is exempt. If the beam-bearer stopped [causing the jug to crash into him], then he is liable. But if the beam-bearer said, “Stop,” then he is exempt. If the jug bearer was first and the beam bearer was second, and the jug was broken by the beam, he [the beam-bearer] is liable. But if the jug-bearer stopped [causing the collision], then [the beam-bearer] is exempt. But if [the jug-bearer] said to the beam-bearer, “Stop,” [but the beam still crashed into the jug], then [the beam bearer] is liable. And likewise in the case of one carrying a lamp and the other carrying flax [which could be ignited by the lamp].
Bava Kama deals with matters of liability for damage caused by a person or his property. In this mishnah, the scene is a crowded thoroughfare where porters are carrying goods, some of them fragile. Our mishnah provides a thorough and fair standard for liability. Carriers of fragile goods are entitled to basic protections, but are not favored to the point that carriers of more durable items are saddled with excessive liability.
In American law, the second car in a rear-end collision is presumed to be liable. Should it matter if the first car made a sudden stop, or are its brake lights equivalent to the mishnah’s shouted warning?