Belief System
A Belief System is a way of thinking -- a comprehensive set of beliefs that reinforce one another because they have a kind of logic that allows believers to prove beliefs true. The foundation of a belief system is a set of axioms -- assertions that are by definition true yet unprovable -- and a logic for deriving other beliefs from the axioms.
Proving the Validity of a Belief System
is a waste of time. Often a Believer, Adam, will try to explain his beliefs to a non-believer, Bert, in terms Adam hopes Bert will understand. Adam will try to prove his belief system valid using the axioms and logic of Bert's belief system.
For example, suppose Adam believes in a religion, and part of that belief system is that "miracles" occur. Miracles are events that can't be explained any other way except by the existence of God. So to Adam, the belief in miracles and belief in God -- two aspects of his belief system -- reinforce one another. A third belief in Adam's system is that non-believers should be converted into believers, because once they believe, they will be happier, better people.
Bert, on the other hand, is not religious. Bert's main belief system is the "Scientific Method". Bert believes, for example, that the "simplest" explanation for an event is the true explanation. Bert believes in "empirical induction", which means things that have always happened a certain way in the past will continue to happen that way in the future.
Adam approaches Bert with evidence of miracles, hoping Bert will adopt Adam's belief system. At first, Adam shows Bert the evidence of miracles, trying to prove to Bert (using Bert's belief system) that miracles happen, and therefore God exists. Bert knows Adam doesn't really believe in the Scientific Method, so Bert doesn't trust that Adam tried hard enough to explain the miracles using Bert's belief system. Bert resists Adam's attempts to subvert the Scientific Method by pointing out that Adams failure to explain the miracles just means Adam didn't try hard enough. Adam retaliates by saying, "OK, Bert, you prove these events aren't miracles." Bert can say he simply doesn't have sufficient skill in the Scientific Method to prove it. Sensing victory, Adam says "Aha! Science can't prove miracles don't happen, so they must be miracles by any definition!"
"Not so fast," says Bert. "First you tell me using the words of your own belief system what God is like." Adam replies, "None of us humans is really smart enough to fully understand God." Bert says, "Adam, don't you see we're at an impasse? Neither of us feels fully competent in our own Belief System, much less the other's. In fact, being less than fully competent in our beliefs is a key part of each of our belief systems.
What Makes a Belief System Survive?
Survival of the fittest. Just like living things, beliefs need to grow and spread in order to survive. It's helpful to think of a Belief System as if it were alive. It lives in the minds of the people who Believe. There, it competes with other thoughts and feelings of its host. The Beliefs may make a person feel better, or smarter, or make the person do things that help other people and make the person well respected and well liked by others. This type of Belief will tend to be reinforced and strengthened in the mind of the Believer. So if a Belief System satisfies a need of its host then it will survive.
How does a Belief System come to rest in the mind of a person? Well, the person could have thought it up all by himself, I suppose. But if that person doesn't share the Beliefs with others, the Belief System will die with him. The person must feel it's important to share the Belief System with others. Then the others may or may not Believe, but will they pass it on to still others? Not unless they Believe that sharing the Belief System with others is very, very important. So to survive, a Belief System must include the Belief that sharing the Belief System with others is extremely important.
Offence: A strong Belief System must have the weapons it needs to establish itself in new minds. A weapon that is a cornerstone of all Belief Systems is the Infinite -- the Belief that a full understanding of the Belief System is impossible for the human minds it inhabits. The Infinite Belief helps make new converts because the non-Believer is not made to feel foolish by the Believer; after all, neither one will ever fully understand the Belief System. Belief Systems that are Infinite will drive out Finite Belief Systems every time using the "miracle" argument: any event that can't be explained using the Finite Belief System disproves the Belief System, however an event that can't be explained using the Infinite Belief System just indicates more work is needed to understand the event.
Defense: Once established a Belief System needs to protect itself from competing Belief Systems. It protects itself by including Beliefs that fight off other Belief Systems. A Belief System needs to be strong to survive. A strong Belief System protects itself by "picking fights" but only the fights it can win in the majority of minds it inhabits. For example, a religious Belief System may include the Belief that theirs is the only True God, and other religions worship false gods. So two competing religious Belief Systems can't occupy the same mind. They will fight each other until one wins. Some religious Belief Systems pick fights with the Scientific Method by including a Belief that the Scientific Method is false. This is a fight the religion might lose in many minds, so many religions choose to temper their Beliefs in such a way that both the religion and Scientific Method can occupy the same mind at the same time. So Beliefs are included in a Belief System to drive out competing weaker Belief Systems but they avoid competing head-on with stronger Belief Systems.