Finding the Hidden Premise

Yesterday, I posted about logic, and I wanted to follow that post up with a tactic that I use when discussing the Bible with skeptics. I call it "Finding the Hidden Premise".

As most people are aware, arguments aren't simply stand alone statements that are expected to be accepted as true. An argument usually consists of one or more premises and a conclusion. The argument is only valid if the premises support the conclusion. Sometimes, however, arguments can have premises that support a conclusion but the premises can be so weak or even silly that simply pointing to the flawed premise is enough to win the argument (even though some skeptics won't concede it even if it is laughably obvious).

In some cases, the premises aren't even spoken; rather, only the conclusion is spoken. For example, if I were to say "Socrates is mortal because all men are mortal," I have stated one premise and the conclusion of the classic deductive argument. What I haven't stated is the missing premise that "Socrates is a man." Because it was unstated, the premise is simply assumed as part of the argument. Of course, if Socrates was a dog, then the argument falls apart because it would state:

P1: All men are mortal.
P2: Socrates is a dog.
C1: Therefore, Socrates is mortal.

The conclusion of the argument is almost certainly true, and both premises are true, but the premises don't support the conclusion. Thus, while it may well be that Socrates the dog is mortal, that isn't shown by the argument.

In some cases, the hidden premise may support the argument but is so far fetched as to be silly. For example, suppose I were to say, ""Socrates is a dog and therefore knows how to fetch his master's slippers." The argument when supplied with the missing premise would read:

P1: All dogs know how to fetch their master's slippers.
P2: Socrates is a dog.
C1: Therefore, Socrates knows how to fetch his master's slippers.

P1, the missing premise, is simply untrue. There are probably more dogs that have no clue how to fetch their master's slippers than dogs that know how to fetch their master's slippers. Thus, the first premise, when revealed, discloses how weak the argument really is.

Often, arguments that are made against Christianity aren’t really arguments but conclusions that have one or more unstated premise. The trick then is to think about what the missing premise might be. For example,

"Jesus never spoke specifically against homosexuality so it is morally acceptable."

This statement is the conclusion of an argument, but the argument itself has two premises one of which is hidden. The hidden premise is revealed in P1, below:

P1. Whatever Jesus didn’t specifically speak against is morally acceptable.
P2. Jesus never specifically spoke against homosexuality.
C1: Homosexuality is morally acceptable.

So, what’s the problem with P1? Of course, it is simply not true that if Jesus didn't specifically speak against something it is now somehow morally acceptable. Jesus didn't speak against rape, slavery, eugenics, and any number of other things that the vast majority of people would find to be morally unacceptable and sometimes against teachings elsewhere in the Bible. It is simply erroneous to conclude that because Jesus didn't specifically address an issue that it is somehow to be construed as Jesus giving it a stamp of approval.

Try some more: “The Trinity can't be supported Biblically because the word Trinity isn’t expressly used in the Bible.”

P1. __________________________________________
P2. The word Trinity isn't expressly used in the Bible.
Conclusion: The Trinity can't be supported Biblically.

So, what is the missing premise, P1? It is, "If a particular word isn't expressly used in the Bible the teaching it describes can't be supported Biblically." Is that true? Of course not. There are lots of teachings that have come out of study of the scriptures, but not all of them use words used in the Bible. For example, the "hypostatic union" (the phrase used to describe Jesus being fully God and fully man) isn't used in the Bible, but it certainly is taught. The word "theocracy" isn't used in the Bible, but that is certainly the type of government that God set up over Israel in Old Testament times.

Here's the tactic: break down the argument to identify all of the premises and see if any are really foolish or self-defeating.