ad ignoranti
The assumption of a conclusion or a fact based primarily on the lack of evidence to the contrary. The statement has not yet been falsified, or is inherently unfalsifiable, and is therefore taken to be true.
> Absence of evidence is not evidence of absence.

A prime example of this fallacy at work can be seen in the Jehova’s Witness efforts to find God in the unanswered questions;
- what came before the Big Bang?
- how did life begin?