(Argumentum ex Silentio, Ad Ignoratiam, Appeal to Ignorance)
This fallacy occurs when individuals take the lack of information about a certain subject as proof of either its existence or nonexistence. Essentially, it’s the belief that something is true because we don’t know it isn’t true, or, conversely, the disbelief in something because we don’t know that it is true. It is often used to justify a position that lacks a certain amount of evidence: proponents of extrasensory perception argue that because we don’t know everything there is to know about the brain that the brain can then send signals; UFO believers often use this argument when they argue that the lack of knowledge about lights or objects in the sky are proof of the existence of UFOs.
(Argument from Incredulity)
This fallacy occurs when someone dismisses something because they personally don’t understand it or can’t imagine how it would work. The basic level of understanding by any one person or even a majority does not dictate what is or is not false. Just because the concepts might be difficult to understand doesn’t make them impossible. Otherwise, most scientific advances that we take for granted today wouldn’t exist. 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.
