Every time that Perry Mason objected that District Attorney Hamilton Burger was “assuming facts not in evidence”, he was accusing Berger of using BZL 1. The essence of this argument is to skip over one or more of the key premises that would have to be proven in a good argument.
A classic example is the question: “Have you stopped beating your wife?” Current examples might include: “Can we afford to restrain economic growth by imposing higher taxes?”
Other names for this technique include begging the question, asking a loaded question, the fallacy of presupposition, and making an argument based on licensed premises.
For example, the argument that “abortion is murder because it involves taking the life of a human being” involves two important presuppositions. First, that a fetus is human being from the moment of conception, a statement that pro-choice advocates might dispute. Second, it rests upon the premise that any taking of human life is murder, when there are instances of taking a life that people would claim are not murder, for example, killing during wartime, imposition of the death penalty, killing in self-defense, and mercy killing.
Pointing out the problem with this argument does not prove that abortion is not murder; it just shows that the argument has to be beefed up by proving the assumptions it rests on. So, for example, the proponent might get a pro-choice person to agree that a fetus is a human being once it is born, and then move back in time to determine the point at which the fetus started being a human being, and then ask why they pick that particular time.
Another way to think about BZL 1 is that one finger is the sign for a fastball. Put up one finger (index finger, please) when it feels like someone is trying to throw a fastball by you. Hitters talk about getting in a place where the ball seems to slow down. That is the goal of BZL 1. Holding the index finger in the air also happens to be the sign for “Hold on just a minute.” Same idea.
Next: What to do if you catch someone making a BZL 1.
