“Taking the Roof Off is not complicated if you follow these three steps.
First, reduce the person’s point of view to its basic argument, assertion, principle or moral rule. This might take a moment of reflection. Ask yourself what the person’s specific claim is. The first step of the Columbo is handy at this point. State the idea clearly (write it out if you need to). If this is part of a conversation, check with the person to make sure you got it right. You might say, “Let me see if I understand you correctly,” then repeat the point as clearly as you can.
Second, mentally give the idea a “test drive” to see where it leads. Ask: “If I follow this principle consistently, what implications will it have for other issues? Will it produce a ‘truth’ that seems wrong or counter-intuitive? Will any absurd consequences result?” The answer to these questions sometimes occurs later, after you have given the issue more thought.
Third, if you find a problem, point it out. Invite the other person to consider the implications of her view and the absurd end that follows from it. Show her that if she applies her view consistently, it will take her to a destination that seems unreasonable. Therefore, something about her original view needs to be modified.
For example, Mother Teresa once appealed to the governor of California to stay the execution of double murderer Robert Alton Harris. Her reasoning: Since “Jesus would forgive,” the governor should forgive.
This argument proves too much, as our tactic demonstrates. When applied consistently, it becomes a reason to forgo any punishment for any crime because one could always argue, “Jesus would forgive.” Emptying every prison does not seem to be what Jesus had in mind because great evil would result. Capital punishment might be faulted on other grounds, but not on this one. Here is the analysis:
Claim: If Jesus would forgive capital criminals, then it is wrong to execute them.
Taking the Roof Off: On this reasoning, it would be wrong for government to punish any criminals because one could always say, “Jesus would forgive.” This seems absurd, especially when Scripture states that the purpose of government is to punish evildoers, not forgive them.
Therefore: Even though Jesus might forgive murderers, that does not mean it is wrong for the government to punish them.”
(Koukl, Tactics, 146-47)