Philosophic burden of proof

This article is about burden of proof as a philosophical concept. For other uses, see Burden of proof (disambiguation).

In epistemology, the burden of proof (Latin: onus probandi) is the obligation on a party in a dispute to provide sufficient warrant for their position.

Holder of the burden

When two parties are in a discussion and one asserts a claim that the other disputes, the one who asserts has a burden of proof to justify or substantiate that claim. An argument from ignorance occurs when either a proposition is assumed to be true because it has not yet been proved false or a proposition is assumed to be false because it has not yet been proved true. This has the effect of shifting the burden of proof to the person criticizing the proposition.

While certain kinds of arguments, such as logical syllogisms, require mathematical or strictly logical proofs, the standard for evidence to meet the burden of proof is usually determined by context and community standards and conventions.

In public discourse

Burden of proof is also an important concept in the public arena of ideas. Once participants in discourse establish common assumptions, the mechanism of burden of proof helps to ensure that all parties contribute productively, using relevant arguments.

Proving a negative

A negative claim is a colloquialism for an affirmative claim that asserts the non-existence or exclusion of something. There are many proofs that substantiate negative claims in mathematics, science, and economics including Arrow's impossibility theorem.

A negative claim may or may not exist as a counterpoint to a previous claim. A proof of impossibility or an evidence of absence argument are typical methods to fulfill the burden of proof for a negative claim.

Example

Matt Dillahunty gives the example of a large jar full of gumballs to illustrate the burden of proof. It is a fact of reality that the number of whole gumballs in the jar is either even or odd, but the degree of personal acceptance or rejection of claims about that characteristic may vary. We can choose to consider two claims about the situation, given as:

1. The number of gumballs is even.
2. The number of gumballs is odd.

These two claims can be considered independently, however, both claims represent the same proposition. Odd in this case means "not even" and could be described as a negative claim. Before we have any information about the number of gumballs, we have no means of checking either of the two claims. When we have no evidence to resolve the proposition, we may suspend judgment. From a cognitive sense, when no personal preference toward opposing claims exists, one may be either skeptical of both claims or ambivalent of both claims. If there is a claim proposed and that claim is disputed, the burden of proof falls onto the proponent of the claim. If there is no agreeable evidence to support a claim, the claim is considered to be an argument from ignorance.

See also

• Evidentialism
• Legal burden of proof
• Metaphysics
• Parsimony
• Pragma-dialectics
• Scientific consensus
• Scientific method
• Statistical hypothesis testing
• Russell's teapot
• Justificationism