Argument from ignorance
|Part of the series on|
“”The very lack of evidence is thus treated as evidence; the absence of smoke proves that the fire is very carefully hidden.
“”[Astrologers will tell you] things like: "Science doesn't know everything." Well, of course science doesn't know everything. But because science doesn't know everything, that doesn't mean science knows nothing. Science knows enough for us to be watched by a few million people now on television, for these lights to be working, for quite extraordinary miracles to have taken place in terms of the harnessing of the physical world and our dim approaches towards understanding it.
Argument from ignorance or argumentum ad ignorantiam in its most formal definition is a logical fallacy that claims the truth of a premise is based on the fact that it has not been proven false, or that a premise is false because it has not been proven true. This is often phrased as "absence of evidence is not evidence of absence".
 Other forms
Another form that this fallacy can take is the form that of an argument from incredulity (also known as argument from personal belief or argument from personal conviction) which is that one's personal incredulity or credulity towards a premise is a logical reason for acceptance or rejection. This incredulity can stem from ignorance (defined as a lack of knowledge and experience) or from willful ignorance (defined as a flat out refusal to gain the knowledge). The concept of irreducible complexity is based entirely around this idea of personal incredulity. One person (Michael Behe) cannot see how something evolved naturally, therefore it can't possibly evolve naturally.
 Use in arguments
Almost all the claims from the anti-science movement revolve around some form of personal incredulity or argument from ignorance.
Proponents of the anti-science movement will usually pick some aspect of a currently accepted scientific theory and argue that it must be wrong because they do not believe it explains some aspect of the natural world. Common examples of this are such claims as "you can't prove global warming is caused by humans," "I don't see how evolution could increase the complexity of an organism," "material properties of the brain cannot presently explicitly explain consciousness so it must be caused by non-materialist processes," or "I don't know how this alternative medicine works, but it does."
 See also
| Articles about logical fallacies|
|Affirming the consequent||Denying the antecedent|
Argument from ignorance
|Fallacious argument styles|