Sometimes Absence of Evidence is Evidence of Absence
“Absence of evidence is not evidence of absence.”
This common aphorism is usually employed by theists who believe it overrides evidentialist objections to theism. In regards to situations where an occurrence or existence would entail the presence of evidence — for instance, like the existence of a god that interferes or has interfered in human affairs in very salient ways (e.g., disrupting natural laws or causing other types of miraculous events) — it is absolutely false.
Logically, if something is said to have interacted with the world in ways that would produce evidence, and a thorough investigation fails to produce non-controversial evidence, then this becomes strong (probabilistic) evidence against the existence or occurrence being asserted.
When this aphorism is addressing occurrences or existences that would produce no evidence, then it is true, but if something produces no evidence we cannot have a meaningful dialogue about its existence or non-existence because we are dealing with an unfalsifiable absurdity. The only appropriate response to such an absurdity is non-cognitivism. Or, more pragmatically, we could use Hitchen’s razor: “That which can be asserted without evidence, can be dismissed without evidence.”
