A post I wrote a couple of years ago, The Ethics of Killing in Self-Defense, received some renewed attention this past week. Judging by some feedback I’ve received, I thought it might be helpful to set the discussion into a larger context, The Ethics of Killing in general, you might say.
The sixth commandment safeguards human life with the prohibition, “You shall not murder” (Ex. 20:13). It should be pointed out, however, that the verb in the commandment (Heb., ratsach) is more general in meaning than “murder.” Kill is the single word that perhaps best captures its meaning. It indicates a range of actions from murder, to causing death by negligence or reckless behavior.
The word which is used in modern jurisprudence is homicide, derived from the Latin homō, meaning man, human being, and the suffix -cide, which indicates an act of killing. Thus the term refers to the killing of a human being. Homicide is a neutral term. Any killing of a human being, whether justified or not, may properly be called a homicide. The word does not necessarily denote a criminal act.
The killing of a human being can be either justified or unjustified. Homicide is justified when it has divine authorization. It is unjustified when it does not have divine authorization. The various kinds of homicide are spelled out in the table below.
Let’s consider this in more detail.
Under what circumstances is someone justified in taking the life of another human being? In other words, when does someone have divine authorization to take human life? Scripture teaches that this authorization is only given in three circumstances: in cases of self-defense, capital punishment, and war.
Killing in Self-Defense
Self-defense is defined as, “the use of force to protect oneself, one’s family, or one’s property from a real or threatened attack.” The right of self-defense is recognized in Exodus 22:2, “If a thief is found breaking in and is struck so that he dies, there shall be no bloodguilt for him.” In other words, the homeowner is not guilty of shedding innocent blood, and consequently is not to be punished. While the act is in progress and the motives of the intruder are unclear, the homeowner is justified in fearing the worst—that the intruder may intend not only to steal, but also to kill. In such a case, the homeowner is not to be charged with the guilt of unlawfully taking human life.
Undoubtedly one has the right of self-defense in other circumstances as well, not only in the home, but also on the street and in the field, wherever there is a reasonable fear of serious harm to one’s person, family, or property. Modern jurisprudence operates on the same principle: “A person may defend himself when attacked, repel force by force, and even commit homicide in resisting an attempted felony, e.g., murder, rape, robbery, burglary, and the like.”
The principles of Biblical law also grant the same immunity to a bystander who comes to the aid of a victim of crime while the crime is in progress.
Biblical law also authorizes the taking of human life as a means of punishment for serious crimes (Gen. 9:6; Num. 35). The death penalty, as it is called, is also known as capital punishment, a term that derives from the Latin, capitalis, meaning “regarding the head,” and refers to execution by beheading. Scripture is very clear that the death penalty can only be imposed by properly constituted authorities who have observed the strictest elements of the due process of law (35:30; cf. Deut. 17:6-13).
The third circumstance in which Biblical law permits the taking of human life is in the context of war. There are numerous passages in which the Lord specifically commands the people of Israel to go to war or prepares them for the prospect for war (Ex. 17:8-16; Num. 1:1-3; 21:1-3, 21-35; 31:1-4; etc.). Of course not all wars are justified. Wars of aggression, and wars merely for the purpose of plunder, whether in goods, territory, or slaves, are unjustifiable. Defensive wars, however, and remedial wars (to recover what was unjustly taken) are justified.
All homicide, except in cases of self-defense, capital punishment, and war is forbidden. It is unjustified, which is to say, done without divine authorization. Unjustified homicide can be either intentional or unintentional. Intentional, unjustified homicide can in turn be either premeditated or unpremeditated. Premeditated, intentional, unjustified homicide is what we call murder. This includes abortion, infanticide, and euthanasia. There is no more serious crime than shedding innocent blood. It is a primeval sin, originating with Cain killing his own brother (Gen. 4:8). It was the chief sin on account of which the Lord sent the flood in the days of Noah (Gen. 6:11-13). We gather this from the command given immediately after the flood: “Whoever sheds man’s blood, by man shall his blood be shed” (Gen. 9:6). This is the first case law we find in the Bible. Innocent blood cries out to the Lord from the ground (Gen. 4:10; cf. Rev. 6:10) and “pollutes the land, and no atonement can be made for the land for the blood that is shed in it, except by the blood of the one who shed it” (Num. 35:33). No sanctuary is to be given to a murderer (Ex. 21:14), and no ransom may be accepted in lieu of his death (Num. 35:31). This is so serious a matter that a special ordinance was enacted in order to atone for unsolved murders so that divine wrath might not come upon the land (Deut. 21:1-9).
Unjustified, intentional homicide might, however, be unpremeditated, as in “the heat of passion.” The manslayer intended to kill his victim at the time, but did not plan to do so beforehand; rather, he suffered some sudden provocation that led him to react violently in the moment (e.g., catching a spouse in the act of adultery; etc.).
Some acts of unjustified homicide are unintentional, like those resulting from reckless or negligent behavior. Biblical law supposes a case in which a man builds a new house and fails to “make a parapet for [the] roof” (Deut. 22:8). (Roofs in the ancient near east were flat and were used for a variety of activities, see Josh. 2:6; Judg. 3:20; 1 Sam. 9:25; etc.) The homeowner was to be held guilty of negligent homicide “if anyone should fall from it.” The same principle is at play in cases where someone fails to cover a pit he has dug (Ex. 21:33-34), or fails to adequately restrain an ox that is in the habit of goring (Ex. 21:28-31). An instance of reckless homicide is supposed in Exodus 22:22-25.
Distinguishing between One Kind of Homicide and Another
Biblical law gives guidance to judges in how to distinguish between one kind of homicide and another. Did the perpetrator lie in wait (Ex. 21:13)? Did he act willfully or with cunning (Ex. 21:14)? Did he use an iron object to strike his victim, or an object made of stone or wood (Num. 35:16-18)? Did he hurl something at him, while lying in wait, or express hatred or enmity toward him (Num. 35:20-21)? Or do the circumstances suggest the death was purely accidental (Num. 35:22-23; Deut. 19:4-5)?
The sixth commandment provides a general prohibition against taking the life of other human beings apart from divine authorization. Such authorization is only given in cases of self-defense, capital punishment, and war. All other killing is strictly prohibited, whether as the result of a willful, premeditated act (i.e., murder), or by reckless or negligent behavior.
 Compare patricide (killing one’s father), matricide (killing one’s mother), suicide (killing oneself), pesticide, etc.
 Black’s Law Dictionary, Abridged Ninth Edition, Bryan A. Garner, Editor in Chief (St. Paul, MN: Thomas Reuters, 2010), p. 1163
 The Law Dictionary (Cincinnati, OH: Anderson Publishing Co., 1986), p. 299
 Scripture teaches that God hates violent, bloodthirsty men (see Ps. 5:6; 11:5; 55:23)
 The passage refers to an ox or a donkey that fall into a pit, but the owner is equally culpable if a human being should fall into it.