Don't dismiss because you can't imagine: Argument from Incredulity

The argument from incredulity, or personal incredulity fallacy, occurs when someone dismisses something because they personally don’t understand it or can’t imagine how it would work. Just because the concepts might be difficult to understand doesn’t make it impossible. Otherwise, most scientific advances that we take for granted today wouldn’t exist. The basic level of knowledge or understanding by any one person or even a majority does not dictate what is or is not false. To avoid this fallacy, when you find yourself having difficulty understanding something, don’t dismiss it until you have gained enough information in order to understand it. This is a common tactic of those who dislike change. If you would rather live in the past and avoid change, then you should avoid taking the time to understand new and complex ideas. This fallacy is related to the argument from ignorance, the difference being that ignorance comes from a lack of knowledge whereas incredulity comes from a lack of understanding or imagination.

How it applies: This is very common in creationist circles who often claim that because they cannot imagine all the complexity of life evolving through natural processes, the earth must have been created by God through single acts of creation (e.g. “I don’t understand how life can just move from bacteria to humans all on its own. There had to be an intelligent designer behind it!”). When creationists attempt to use seemingly-“irreducibly complex systems” as “proof of God,” they are committing this fallacy (and, as it turns out, these systems have continually been explained through science). Atheists also use this fallacy when they claim that they "don't understand how/why God would have" done one thing or another and use it to justify their unbelief. This is usually in terms of "why God allows evil" if he is an all-loving God.

Examples:

• “The odds against a molecule arranging itself perfectly are astronomical! Therefore, it disproves evolution because it had to have been designed!” (This ignores the fact that chemicals don’t arrange randomly; laws govern how atoms interact and form molecules.)
• “The human mind is so complex, you can’t conclude there is no soul released after death.”
• “I cannot accept a universe without ultimate meaning/purpose/justice for good and evil; therefore, I believe in God.”
• “I can't believe in a God that will only accept one way of belief and condemn all unbelievers to eternal punishment or that would not give me the freedom to live my life how I choose.”
• "I simply cannot see how the universe could be expanding"
• “I just don’t see how any guy could be attracted to another guy, so I know gays choose their lifestyle.”
• “I don’t understand that engineer’s argument about how airplanes can fly. Therefore, I cannot believe that airplanes are able to fly.”