Negative proof

From Wikipedia, the free encyclopedia

This article is about a logical fallacy. The term "negative proof" can also refer to a proof of impossibility.

Negative proof, the fallacy of appealing to lack of proof of the negative, is a logical fallacy of the following form:

"X is true because there is no proof that X is false."

It is asserted that a proposition is true, only because it has not been proven false. The negative proof fallacy often occurs in the debate of the existence of supernatural phenomena, in the following form:

"A supernatural force must exist, because there is no proof that it does not exist".

However, the fallacy can also occur when the predicate of a subject is denied:

"A supernatural force does not exist, because there is no proof that it does exist."

"Scientists don't know for sure what natural forces caused the first single-cell life, so it must be intelligent design."

1 Appropriate occasions
2 See also
3 References
4 External links

[edit] Appropriate occasions

In some cases a reversed burden of proof may be appropriate. This occurs when there are two competing explanations, and neither can be confirmed by observation. For example: when an empirical relationship has been observed, but the underlying mechanism is unknown, it may be reasonable to infer from the lack of conflicting evidence that the observed relationship is most likely causal. (c.f. Correlation does not imply causation) (See also: Inference to the Best Explanation)

Criteria for selecting the best explanation in this case could involve Occam's razor, which states that the best explanation tends to be the one requiring the fewest additional assumptions. Such an explanation invokes the fewest intermediate factors while maintaining its predictive power; that is, its ability to explain current data and to predict future data.^[1] However, according to the scientific method, the relationship is not formally proven in this instance, and to assert that it is so until disproven is fallacious.

In criminal law, the lack of proof of guilt is evidence for innocence in the eyes of the law. In this context, it is acceptable to say "the accused must be found not guilty because there is no proof that he or she is guilty." However, a legal finding of non-guilt does not imply that the defendant did not commit the crime. It only means that for the purposes of law, the defendant is assumed not to be guilty.