In Parshat Mishpatim (21:28), the Torah says that if an ox gores and kills a man or a woman, then the ox shall be stoned, and its meat shall not be eaten, but the owner of the ox is innocent. Why is the death penalty administered to an animal?
The Rambam suggests that the harsh punishment is not given to punish the ox; rather, it is a motivation to the owner of the animal. The owner knows that he cannot derive any benefit from such an animal, and that motivates him to watch his animals more closely. This motivation is reinforced by the case where the ox is known to be dangerous and an extra fine is levied against the owner. Ibn Ezra and the Ritva agree with the Rambam.
The Ralbag, however, disagrees. He argues that since the Pasuk says that even an ownerless ox is to be stoned, the purpose cannot be to motivate owner, since in this case there is no owner. The Ralbag says that the ox is punished harshly to protect society against creatures that can cause serious harm to others.
However, the Rambam offers another opinion. He says that it is clear from Bereishit (9:5) that animals can be held responsible for shedding human blood, since the Pasuk says, “However, your blood which belongs to your souls I will demand, of every beast will I demand it.” Certainly, says the Rambam, sin and atonement are concepts that do not apply to animals. However, the execution of a murderous animal is required as a Divine decree, issued in honor of man who was created in the image of God. Given the power to execute judgment, be it over man or animal, man will realize and appreciate the great dignity of his own existence.