Responding to the charge of Argumentum ad Ignorantiam
The fallacy of arguing from ignorance does not apply in all cases in which we point to ignorance or a lack of evidence as basis for a conclusion. It does not follow that one argues fallaciously from ignorance whenever one argues that ‘P’ is not likely because there is no evidence adduced for ‘P’. (Suppose that ‘P’ represents the claim that Muslims secretly plan to overthrow the U.S. government.) Sometimes our best information is that there is no evidence to support the claim that P, and when we point this out we are not committing the fallacy of “argument from ignorance.