The AIP Test concerns Arbitrariness, Inconsistency, and Preconditions of Intelligibility. What do these have to do with each other? Well, if you can spot Arbitrariness and Inconsistency in someone's arguments, then that's a hint that whatever they might believe in and think is true, there's a good chance that they don't have a good reason for doing so. Preconditions of Intelligibility are things that must be assumed before one can even begin to reason in the first place, but if one's worldview cannot account for their existence (you still need to have a reason for why you use them, even if they must initially be presupposed), then there's a good chance that that person's worldview is wrong.

Arbitrariness

In Logic, no one is allowed to be arbitrary. If one can arbitrarily claim one thing to be true, then one's opponent can simply arbitrarily claim the exact opposite to be true. Contradictions cannot both be true, so what's the solution? 

Everyone must have a reason for what they believe. Not everybody bothers to think of the reason for everything they do, but that's not necessarily necessary--what's necessary is that there IS a reason, whether or not the person has painstakingly mapped out every thought sequence in their experience. 

If you don't have a reason for what you profess to know to be true, how do you know it's true? Essentially, you cannot answer any question, since the answer to a question is a reason. You cannot answer 'WHY,' because the (sufficient) answer to the word 'WHY?' is an answer. If you said, 'I believe that I am alive,' and I asked 'why,' you cannot answer me without giving a reason. If you do not give a reason, you're just being arbitrary. How do you know you're alive? One possible answer could be that you are breathing, and only living things breathe. You have given a reason for your claim, and your primary claim is not arbitrary. However, your secondary claim might be arbitrary unless you have a reason for it. How do you know that only living things breathe? Or, to phrase it with the word 'why,' 'Why do you think only living things breathe?'

Now, asking 'why' in a continuous sequence usually leads to hilarity, since you arrive at a point where the person asking the questions needs no more proof. Most people believe in certain AXIOMS, and these are propositions that are not proved in the logical proof, because they are assumed (accepted by the arguer) to be true. If both people agree to the same axioms, then debate can continue. This is how most argumentation occurs. The arguers accept the same axioms, and proceed to attempt to prove claims that they derive from the axioms.

But you still need a reason to accept the axioms. Even if you don't bother to prove them in a given argument, ultimately you must have a reason to believe in them, OR YOU WOULD HAVE NO REASON TO BELIEVE IN THEM.

Did you catch that?

Axioms are propositions that are assumed/accepted to be true. Presuppositions are axioms (they're pretty much synonymous), but they are generally left unstated. They are assumed by the arguer. This is well and good, if their opponent accepts the same presuppositions, but if not, the arguer must be made to recognize that he has these presuppositions and to account for why he has them. Preconditions of Intelligibility are presuppositions that MUST be assumed in order to even begin to reason. However, they cannot be arbitrary. How then can one account for Preconditions of Intelligibility? One must first assume them in order to reason, and then use reasoning to demonstrate that one must assume them in order to reason, because otherwise reasoning would be impossible. This sounds similar to circular reasoning. It is a form of it, but it is not a vicious circle. Vicious Circular Reasoning is arbitrary, and fallacious. But in arguing for Preconditions of Intelligibility, one must use circular reasoning. However, this is not arbitrary, because you have a reason to do it--the reason is that if you did not at first assume the Preconditions of Intelligibility, you wouldn't be able to reason at all, and it would be impossible to prove anything. This won't do. Obviously, some degree of circular reasoning must be involved in order to prove anything, but it cannot be arbitrary, because then it will be a fallacious vicious circle.

Inconsistency

If a person's worldview is inconsistent, then that means that they are professing something to be true, but acting in a way that is not consistent with their claim(s). For example, a person can profess that there is no such thing as an absolute truth. But that claim is an absolute truth, so they refute themselves with their very argument. If it were true that there were no absolute truths, then the claim that there are no absolute truths is false, and so the original claim is false. If it's false, it's still false. So whether it's true or false, it's false. This is the hallmark of a false worldview. It contradicts itself, so it cannot be true. The claim that two contradictory claims are both true must be a false claim. If someone said that it is true that the light is green, and it is not true that the light is green, then whether the light is green or the light is not green, their claim that the light is green and not green is false. If someone says, 'You can't tell other people what to do!' they have refuted themselves, because they have done what they claim you cannot do. Their worldview is inconsistent, and therefore it is false.

Preconditions of Intelligibility

These were explored in some detail above, but suffice it to say that one must presume certain things in order to reason:

1. The existence of laws of logic (correct reasoning)
2. The existence of laws of morality
3. The uniformity of nature (not to be confused with uniformitarianism)
4. The understandability of human language.

As part of #3 above, one must presume the reliability of one's senses and memory in order to reason. If one's memory is unreliable, how can you know for certain if what you believe is true, really is true? After all, your memory of this is of the past. Let's say you took a memory test to determine that you have a good memory. But you would have to remember how well you did on it in order to know whether you did well, and if your memory is unreliable, how do you know if you did well on it? 

One must assume these things or have one's reasoning reduced to absurdity. But WHY must you assume these things? WHY are they necessary for correct reasoning? How can you know that these things must be presumed, and how do you know that what you're assuming to be true really is true?

The above paragraph is a crucial thing for anyone with a self-consistent worldview to determine. If your worldview cannot account for the existence of Preconditions of Intelligibility, it is inconsistent. If it is inconsistent, then it cannot account for itself, and therefore must be accounted for by something else--a different worldview. Therefore, whatever worldview can account for something that a different worldview cannot must be truer than the different worldview. The only true worldview(s) will be the one that explains everything that can be known, and doesn't need to appeal to anything greater than itself.

It must explain and account for itself.

Next installment will deal with the broad categories of fallacies of Ambiguity, Relevance, and Motive.

Part 3: http://my.umbc.edu/discussions/455?page=1&page_size=25
Part 5: http://my.umbc.edu/discussions/478