Investigations take place all the time. People investigate different happenings and phenomena throughout the world. Investigations are how we come to understand and are able to explain things. In any investigation, a series of evidences are compiled. Any explanation that is to be considered plausible must account for all the evidence. Investigators attempt to enter an investigation without any assumptions prior to seeing evidence. The truth is that an investigator has a reason for investigating otherwise investigating would be of little value.
Many times an investigator has an idea that he wants to verify, or just see if it is correct. Other times, the investigator has no idea what happened, but something that he stumbled upon makes him want to learn more. It is quite important that an investigator recognize that (s)he is not objective and be willing to go where his acquired evidence is leading. For example, a crime scene investigator should not go to a crime scene already convinced that the crime was not a murder. This a priori (prior to evidence) conclusion may stifle the investigation (and conviction of a suspect) if the crime was, in fact, a murder. If the evidence points to a murder, and the investigator rejects that hypothesis, they may stall the investigation until some other explanation is available to him(her) to explain the evidence. This is not allowed in crime scene investigations because law enforcement has records upon records of cases that the current case may be compared to. If the evidence is similar, it is valid to rule the crime to be a murder. Then the search for a suspect may begin.
No single piece of evidence may be used to build a case or conclude the type of crime. Not very often does a single piece of evidence point to the possibility of only a single type of crime (see The Danger of Overstated Conclusions). When that is multiplied by the pieces of evidence, you end up with many possibilities of crimes for each piece. However, investigators look at all the different crimes that each piece of evidence points to and finds the common crime among the pieces of evidence.
This same process is used to determine suspects. In a court of law, the evidence is presented by the prosecution. However, they do not only present a single piece, since a single piece may point to other possibilities of crimes or suspects. The prosecutors present a "cumulative case" that consists of all the evidence. They also provide a scenario that consistently explains all the evidence.
At this point, the defense is supposed to either show how the evidence is not valid or show how the evidence can be explained consistently by some other crime or suspect (not their's). Sometimes the defense may even attack the prosecution's interpretation of the evidence. In the end, the crime, suspect, and scenario that consistently explain the event are to be held to be true, and a verdict is presented on those grounds.
Part of the "cumulative case" is providing evidence against opposing options. The prosecution may also provide evidence that eliminates specific crimes or suspects from the line that the defense may offer as an alternative possibility. Both positive arguments and evidence (for the prosecution's case) and negative arguments and evidence (against the defense's case) are part of a cumulative case (See Positive and Negative Arguments).
Our decision to follow a specific worldview should be no different. Many philosophical and scientific truths have been discovered about the world we live in. We must acknowledge them all and be willing to allow ourselves to be guided by the evidence to a conclusion rather than by our a priori commitments. No one comes to any investigation without some idea. Complete objectivity is not possible. We need to not deceive ourselves into thinking that we are completely objective, and humbly recognize our biases enough that if the evidence points us another direction, we follow it.
As I mentioned, anyone who is defending their worldview must provide both positive and negative arguments. Many people believe that they can turn someone to their worldview by the process of elimination (only negative arguments, no positive ones). If the person is already convinced against a specific worldview, they tend to assume the position of ignorance rather than accept the worldview they are convinced is wrong (See Filling in the Gaps). However, other people only provide positive arguments. It does not do much good to only show that your worldview can account for all the evidence...the other person may also be able to do that- giving them no reason to accept yours over theirs. Both positive and negative arguments and evidences must be provided. Positive for why your worldview should be accepted, and negative for why another worldview should be rejected. In isolation from one another, the positive and negative arguments and evidences may only get people as far as taking an agnostic position. Together, however, they provide a path to successfully transition from one worldview to another.
A cumulative case has "power in numbers" on its side. If a conclusion has 100 pieces of evidence and lines of reasoning that support it, one piece or line that goes against it may not necessarily bring the whole thing down. That single piece or line may need to be verified or reinterpreted (see Nature vs. Scripture), but cannot be ignored. If someone is aware of the large cumulative case for their worldview, one discovery is not likely to bring their belief of their worldview down.
I was recently asked about challenges to a worldview. It was proposed that sometimes a person who is being challenged may simply not have the understanding of the challenge to recognize that the implications pose a problem to his cumulative case. I think that this happens all the time. If someone continues to say that there is not an error, without providing reasons, they are living in denial (one of the psychological defense mechanisms). This could be due to being afraid that they may actually be wrong. Another cause could be that someone thinks so highly of their own abilities that they can't possible be wrong. The former further leads to rationalization (another defense mechanism)- reasoning that doesn't actually target the challenge (but sounds "smart" enough to appease the challenged or his/her audience or even him/herself). The latter leads to simply ignoring the challenge. Both are emotionally charged and the result of not having a powerful cumulative case. We do not know a person's psyche precisely (no credible psychologist, psychiatrist, or neurologist can say that we even have the ability to), but we can reduce the possible options. Either direction a person chooses to go, they are exhibiting at least one defense mechanism and either employing a second (in the case of the former) or suffering from a form of narcissism (in the case of the latter). Regardless of the direction, it is academically dishonest and stifles the search for truth.
Another way to stifle one's search for truth is to be merely acquainted with a position. Simply "knowing of something" (a challenge in this case) allows for easy emotional dismissal of it. "Understanding why and how something is" makes the emotional dismissal a little bit more difficult, but more powerful and dangerous. If you just "know of" a something, you can easily change your mind about your acceptance of it. However, if you "understand" something and still choose to dismiss it, you will rationalize a stronger case against it, making it more difficult to ever accept it.
Likewise the possession of a cumulative case distinguishes between those who simply know of a view and those who truly understand a view. Here is what I mean: Simply "knowing of something" (a worldview in this case) allows for easy emotional dismissal or acceptance of it. "Understanding why and how" the worldview is true (false) makes the emotional acceptance (dismissal) much easier, and the cumulative case more powerful if accomplished. On the flip side (watch closely), "understanding why and how" the worldview is true (false) makes the emotional dismissal (acceptance) of it much more difficult, but the cumulative case more dangerous if accomplished.
The dangerous cumulative case is what leads people into deep delusions about reality. These false beliefs (no matter how strong the cumulative case) are still against reality, and reality is always ready to remind us that it is still where we live. The majority of these reminders come in the form of pain and confusion (both emotional and logical). I'm not saying that we will ever be able to have no pain or confusion; that would require omniscience (a perfectly, precisely, accurate worldview). We are still human with limited knowledge and understanding of everything. A cumulative case-based worldview will just help reduce the pain, confusion, and confusion about pain.
Of course, simply experiencing less pain and confusion does not necessarily mean that you have a cumulative case for the correct worldview. It could also mean that you are just deeper in your delusion, as I hinted towards above. I have said for a long time that pain is not necessarily bad. It will paralyze our logic and reason while we deal with the emotional side of a situation. When dealing with worldviews, pain is partly caused by not having a complete understanding of reality. That pain (whether imposed by a person in the form of a challenge or imposed by experience with reality) provides us with an opportunity. After our emotions are done paralyzing our logic and reason (differing amounts of time based on the situation and the person), we have the chance to seize the opportunity provided to build a stronger cumulative case for our worldview. But once again, pain will never be completely removed. In fact, I would argue that if pain is removed, then the person is further in their delusion.
People, who are challenged, should investigate the challenge- especially if they are challenged on a ground that they are unfamiliar with (interdisciplinary consistency is vital to a cumulative case for a worldview- see Consistency Among Disciplines). This provides an opportunity to change, adjust, or nuance an argument; all those will lead to a stronger cumulative case for one's worldview. Careful thinkers and investigators will realize that true humility (as difficult as it is to sustain for long periods of time) provides an avenue for creating robust and accurate worldviews. At that point, we may be confident enough that a challenge can be accepted. Even if that challenge turns out to be not only valid, but correct, only one piece of the many pieces have been destroyed. Time to adjust for benefit.
As we discover more that we don't understand and work through it, our understanding of our worldview will become more complete. More complete understanding allows us to possess and present an extremely powerful cumulative case to anyone who asks for the reason for the hope we have. However, it is quite difficult to communicate an entire worldview that the cumulative case is supporting. This really made me realize the importance of 1 Peter 3:15 ("...Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect").
Many times people ask me to go into great detail explaining a certain aspect of my worldview. It is expected that I can do this in a simple blog post or semi-short email. Considering the fact that many scholars have written many volumes about the many different worldviews, this seems to be quite a "tall order". Many times it is easier for someone to just ask single questions at a time and allow me to answer them. Because of this, I will have to answer the same questions many times for many people, and sometimes I may have to answer the same question for the same person multiple times (especially if its been a while since the first answer was provided).
The fact that I find myself repeating over and over again gets quite frustrating, and if its the same person the frustration goes to a whole new level. To prevent this, I need to remember that the person is not asking a simple question, and I am not providing a simple answer. Sometimes it will take a few times of hearing the answer to comprehend it. Also, not everyone is aware of the answers to their questions, so the answers must be repeated.
Keeping my cool and providing the answers in a respectful and loving manner is part of my witness. As much as we don't like it, what we say is not the only thing that has the power to persuade people. Our attitude and character play a huge part in it.
I must always be prepared, but I must not stop there. I must remember the rest of what Peter said- "do so with gentleness and respect." I cannot communicate every aspect of my worldview to every person every moment that I speak or write.Understanding this helps me to keep my frustration (and ego, for that matter) in check as I defend the truth of the Gospel of Jesus Christ.