Argument from ignorance is an informal fallacy where a claim is asserted as true or false solely because it lacks proof to the contrary. The fallacy occurs when one concludes a proposition is true because it hasn't been proven false, or vice versa. While generally considered fallacious, limited exceptions exist, such as in legal proceedings where the presumption of innocence applies.
A research paper proposes the Claim-Offence Theory, which argues that the burden of proof for a claim should scale with its cost to those it affects; the theory is tested on false accusations, public-health claims, and religious doctrines.