Argument from incredulity

Argument from incredulity, also known as argument from personal incredulity or appeal to common sense,[1] is a fallacy in informal logic. It asserts that a proposition must be false because it contradicts one's personal expectations or beliefs, or is difficult to imagine.

Arguments from incredulity can take the form:

1. I cannot imagine how F could be true; therefore F must be false.
2. I cannot imagine how F could be false; therefore F must be true.[2]

Arguments from incredulity can sometimes arise from inappropriate emotional involvement, the conflation of fantasy and reality, a lack of understanding, or an instinctive 'gut' reaction, especially where time is scarce.[3] This form of reasoning is fallacious because one's inability to imagine how a statement can be true or false gives no information about whether the statement is true or false in reality.[4]