Shall We Reason Together? Part Ten: Extra-Biblical Premises

This series of essays began by discussing the usefulness of logic as a tool for discovering biblical truth. Until now, the question has been whether necessary inferences from the Scriptural premises are somehow less authoritative than the original premises. These essays have argued that whatever Scripture necessarily implies is just as authoritative as what Scripture actually states.

The assertion of this authority must be qualified both when the premises are probable rather than certain, and when the arguments are inductive rather than deductive. Even so, if the degree of probability is so high as to constitute virtual certainty, then the conclusions should be pressed as strongly as the statements of Scripture itself. Indeed, since all biblical statements must be grasped inductively, all of our teaching rests upon probability rather than Cartesian certainty.

One further question should be addressed. How strongly can conclusions be pressed when one of the premises upon which they rest is extra-biblical? This is a complicated question, and giving a facile answer would be foolish. We do not need to explore every part of it, however. What we really want to know is whether the conclusions of these “mixed” arguments are ever as authoritative as the text of Scripture itself.

We can answer this question best by examining some definite command of Scripture. Let’s take, “Thou shalt not kill.” Sensible interpreters immediately understand that this command does not forbid all taking of life (or else how could the priests offer sacrifices?), but rather the commission of murder. This recognition leads directly into a discussion of the definition of murder. Does a soldier commit murder by taking the life of an enemy combatant in a just war? Does an executioner commit a murder when carrying out the capital punishment at the direction of the commander of Auschwitz? Is it murder to kill in self-defense?

When we have answered these questions and arrived at a satisfactory and exegetically informed definition of murder, our work has only begun. Even if we can get a strictly biblical definition of murder, that still does not reveal every act that will lead to murder.

Imagine a case in which the victim has been shot through the head and died. The shooter admits pointing the muzzle of the gun at the victim’s forehead and pulling the trigger. He insists, however, that this was not an act of murder. He notes that Scripture never says anything about how guns work. It nowhere states that pulling the trigger launches a projectile. Furthermore, there is no biblical revelation that a .357 hollow‐point passing through the brain at 1,300 feet per second will cause death. Such facts fall purely into the sphere of extra‐biblical knowledge. Since our shooter is committed to Sola Scriptura, he insists that “secular” information about external ballistics, human brain function, and firearms mechanisms must be excluded from the conversation. Pointing a loaded gun at someone’s head and pulling the trigger cannot be called murder, he claims, because the Bible never says it is murder. The connection between this act and the death of the victim rests solely upon fallible human observation and experience. To condemn the shooting as a murder is to go beyond Scripture.

This is admittedly an imaginary case, but it is no longer an extreme one. One can find evangelical ethicists who argue that sexual “petting” is not immoral as long as it stops short of intercourse. One can find evangelical rappers who think they can shout obscenities because the Bible does not list the exact words that constitute “corrupt communication.” One wonders if any behavior at all is too bizarre for evangelicals (often including fundamentalists) to defend.

The fact is that virtually any specific behavior can be defended if we insist that biblical commands and principles must be applied without reference to any outside sources of knowledge. If we limit ourselves that way, then nothing can be evaluated in terms of its actual effects or parsed for its actual meaning. If we are left with the bare statements of Scripture, sans knowledge of the world, then virtually all of biblical morality evaporates. It turns out that Bill Clinton did not commit adultery, or even an impropriety, with Monica Lewinski, except perhaps from a cultural point of view. After all, where does Scripture specifically say that their particular method of trysting is adulterous? The president could honestly swear, “I did not have sex with that woman.”

Sure, Bill.

Most of the time, applying the commands and principles of Scripture requires extra-biblical information. The scriptural demand forms one premise of a moral argument, but the other premise is supplied by knowledge about the world. A sound conclusion relies upon both premises. Cut off the second premise and you cut off your ability to apply to real life virtually all biblical commands and principles. Elementary maxims like “thou shalt not steal,” become virtually irrelevant to daily living. We may say that stealing is taking without permission a thing that belongs to someone else, but the Bible does not reveal what belongs to whom.

I am not suggesting that the conclusions to “mixed” arguments are always as authoritative as Scripture. Their authority depends upon the truth of the second premise, and that premise has to stand or fall on its own merits. How we ought to evaluate the probability of the second premise is a topic that deserves a separate discussion.

When the truth of the second premise is certain or highly probable, however, then the mixed argument (if it is sound) must stand with all the authority of Scripture itself. To point a loaded gun at someone’s head and pull the trigger really is homicide, even if we have to rely upon extra-biblical information to know it. If we are not willing to recognize that moral arguments have to rely upon the second premise, then we are dooming ourselves to the Gehennah of moral nihilism.

Clasping of Hands.

George Herbert (1633)