Generally, statement of belief makes reference to the object of belief, which is not a mere psychological state. Although belief often involves some state of mind, the object of most of our beliefs is something other than our psychological state of mind.
In a recent review of John Gray’s book, The Immortalization Commission (Science and the Strange Quest to Cheat Death), Clancy Martin (professor of philosophy at the University of Missouri, Kansas City) praises Gray for an interesting account of the weird and fascinating search for evidence of life after death. But Martin is bothered by what he claims is a basic fallacy in Gray’s dismissal of the likelihood of any positive results from the on-going search for life after death.
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.