Wednesday, August 19, 2015

The Inconsistency Fallacy

A particular informal argument pattern, which I call the inconsistency fallacy, is becoming more common in culture-war battles. The inconsistency fallacy goes something like this:

  • Advocate A holds position on policy p1, which (presumably) has quality q.
  • However, Advocate A also holds positions on policies p2, p3, etc., which are not-q or anti-q.
  • Either q or not-q should be supported.  (Implied premiss.)
  • Therefore, Advocate A must give up his position(s) on either p1 or on p2, p3, etc.

Here’s a paraphrase of one variant I saw earlier this evening: “If you don’t want to sell food for a gay wedding because you don’t want to support sodomy, then you shouldn’t support gluttony by selling to fat people; you shouldn’t sell to divorcées, or to thieves, or to ....” Another variant I’ve seen: “If you’re against abortion, you should also be against capital punishment; you should be against hunting; you should be a vegan; you should be yadda-yadda-yadda ....”

It’s implied, and often stated, that if you don’t resolve the apparent inconsistency by abandoning position p1, then you, sir/madam/small child, are a hypocrite, and we therefore need not pay attention to position p1. Although the inconsistency fallacy shares some of the features of the red herring and the abusive ad hominem, it’s best classified as a sub-species of the false dilemma.

In formal logic, a dilemma takes the following form:

POSITIVE
NEGATIVE
If p is true, then q is true.
If r is true, then s is true.
Either p is true or q is true.
Either r is false or s is false.
THEREFORE:
Either r is true or s is true.
Either p is false or q is false.

In polemics, the opponent (call him “Advocate B”) usually resorts to a dilemma to trap Advocate A between two unpalateable positions, in the hope of creating a Hobson’s choice. You can either expend a lot of energy and lose a lot of money by turning away every kind of sinner from your business, or you can simply overlook this particular sin as you overlook the others. Or, You can refuse to tolerate killing in any case, or you can tolerate killing in this case as well as the others.

What makes it a false dilemma? As in the meme, a dilemma is false when more than two reasonable options are present. The inconsistency fallacy presumes that quality q is the only quality necessary for determining whether px is true or false, or for determining whether policy px is tolerable or not. Advocate B’s argument, reduced, is: You must tolerate nothing that violates quality q, or you must tolerate everything that violates it; you don’t get to pick and choose what violations you won’t tolerate.

Even if we granted the “all” and “nothing” positions to be themselves reasonable, the burden of proof falls on Advocate B to show that there are no moral or pragmatic reasons to tolerate some things but not others. Advocate B would also bear the burden of showing that quality q is relevant to policy p1, and that Advocate A’s position on p2, p3, and so forth really do deny or violate that quality. Put differently, the inconsistency fallacy presents several rabbit holes down which the discussion can fall; that’s its “red herring” feature.

The charge of hypocrisy nothing to do with the merits of a particular argument or position, and everything to do with the character of the person who advances it. Ideally, we analyze the merits and weaknesses of arguments without reference to the person putting them forth. In the real world, it sometimes happens; for instance, the same professional journal which thirteen years ago published a paper by an historian from the University of Illinois printed a refutation of that paper that was written by a Maryland high school student. More often, though — too often — we confuse the credibility of the advocate with the merits of his argument; we give credibility on a subject to whom it isn’t due, or deny it to a person on grounds that are irrelevant to the argument. Advocate A may indeed be a hypocrite for holding the positions he does on policies p2, p3, and so on ... but that has nothing to do with the logic or facts supporting his position on policy p1. Attack the argument, not the person making it.

In sum: The inconsistency fallacy is an argument which holds that a position is false because it is inconsistent with other positions which the advocate is presumed to hold and which the opponent asserts are related to the position in question. It is a fallacy because it implicitly assumes no relevant dissimilarities between the facts of the issues which would demand the advocate take different positions on them. It is also a distraction, as discussion of the relevant similarities and differences is almost always beyond the scope of the topic. It is also an implicit, and sometimes explicit, attack against the character of the advocate, which is irrelevant to the truth or validity of his argument.

That is all. Semper Fi.