LESSON 4.

THE BURDEN OF PROOF, PRESUMPTIONS, AND REFUTATION

INTRODUCTION

The lack or absence of presumption and burden of proof standards lead to irresponsible and flimsy argumentation.
"Argumentum ad ignoratum," or, "the argument that I am making needs no proof; it is presumed correct until my
opponent proves it wrong."
Example of the "argumentum ad ignoratum" fallacy: when affirmative debaters claim that instead of
the affirmative needing to prove the resolution true, it is the responsibility of the negative side to prove
the resolution or proposition false.

Learning Outcomes: At the end of this lesson, you will be able to:
a. explain and determine the difference between burden of proof and presumption, and the
burden of refutation.

PRE-ACTIVITY

Reflect on why the obligation of proof rests with the person who makes the claim, not the one who denies the
claim.

A. The Burden of Proof (Latin: “onus probandi”)

(SOURCE: Anon. (n.d.). The Burden of Proof: Why People Should Support Their Claims. https://effectiviology.com/burden-of-proof/)

The burden of proof (“onus probandi” in Latin) is the obligation to provide sufficient supporting evidence for
claims that you make.

Examples of situations where the burden of proof is observed:

If a politician claims that a new policy will lead to a positive outcome, then the politician has to provide evidence
that supports his claims.

If someone claims that their solution to some problem is better than the alternatives, then they need to provide
evidence that shows that this is indeed the case.

If a scientist claims that their theory can explain a certain natural phenomenon, then the burden of proof means
that they need to provide evidence that supports this claim.

If a person sues someone for causing them financial losses, then the burden of proof means that the person who
is suing needs to prove in court that the other person is responsible for those losses.

If a company claims that a medication that they developed is effective and safe, then the burden of proof means
that they need to support this claim using clinical data.

Who has the Burden of Proof?

(SOURCE: Elsher, P. (n.d.). Burden of Proof Fallacy: Who Has the Burden of Proof and Why? Fallacy in Logic.
https://fallacyinlogic.com/burden-of-proof-fallacy-definition-and-examples/)

In a debate, the affirmative team always has the burden of proof. The team can uphold its view by proving
that:

a. there is a need for a change in the status quo (the current state of affairs, the present system) relative
to the proposition;

b. that the affirmative side has a plan for change and a proposal for implementation; and

c. that there are precise advantages and benefits to such a plan and proposal.
The opposing side does not have a burden of proof until evidence has been provided for the original
argument. However, once the evidence has been provided, it is up to the opposing team to show if the
evidence is insufficient. If the opposing team argues that affirmative’s claim is invalid, then, in turn, the
burden of proof is on them to justify the disagreement.

As Christopher Hitchens famously stated: What can be asserted without evidence can be dismissed
without evidence.

Burden of Proof Fallacy

The fallacy of shifting the burden of proof occurs when someone/affirmative side making a claim does
not respect their obligation to provide the needed evidence for it, but instead attempts to shift the burden
to their opponent/negative side.

Example 1
Jack: “I’m certain that ghosts do exist.”
Sarah: “What makes you so certain?”
Jack: “Well, can you prove that they don’t exist?”
Sarah: “I guess I can’t.”
Jack: “Then you have to accept that I’m right.”
Jack challenges Sarah to disprove his claim without offering any justification for it himself. In other words,
he shifts his burden of proof to Sarah.

In this example, Jack also commits the logical fallacy of appeal to ignorance, which is closely related to
the burden of proof fallacy and often appears together with it.

Example 2
Fred: “Santa Claus is not a real person, only children believe that he is.”
Nick: “I believe he is real. Can you prove that he isn’t?”
Fred: “Do I really have to prove it to you?”
In a case like this, the burden of proof is seen to lie with Nick: his assertion of Santa Claus being real is
against common knowledge and should be justified first.

Example 3
Mike: “I think celebrity X is having an affair.”
Delilah: “Are you sure?”
Mike: “Yeah, I read it in the Daily Gossip.”
People sometimes evade their burden of proof by attributing their claim to a secondary source. And,
although it can be acceptable to refer to a secondary source’s opinion, it often leads to a weak argument
if it is being used as the main evidence for a claim, especially if it is done in order to avoid the burden of
proof.

How to counter the burden of proof fallacy?

The following are several ways that you can do to respond to someone’s attempt to evade their burden
of proof:

 Point out that they have failed to fulfill their burden of proof. When doing this, you can explain
what burden of proof they have and why they have it, based on the claims that they have made.

 Explain why they are the ones with the burden of proof. This is especially relevant in cases
where they attempt to shift their burden of proof to someone else, for example by asking someone
to disprove their claim, when they are the ones who should be proving it.
  Ask them to fulfill their burden of proof or retract their claim. When doing this, you can also
set conditions, such as that you would not continue the discussion until they have fulfilled their
burden of proof, while also explaining why it is important that they do so.

 Call out the attempted evasion of the burden of proof. This can involve pointing out the specific
way in which the person in question is evading their burden of proof, especially if they’re doing it
by using other fallacious patterns of reasoning.

 Provide counter-proof. In some cases, it can be preferable to prove or disprove something

yourself, rather than focus on someone else’s inability to fulfill their burden of proof, for example
if the discussion won’t go anywhere otherwise. However, note that a failure to provide counter-
proof on your part does not necessarily constitute evidence that can be used in order to support
their stance, especially if their claims are phrased in a way that makes them inherently difficult or
impossible to disprove.

 Focus on your own point. In some cases, it can be preferable to ignore the other person’s point,
given their evasion of their burden of proof, and to instead focus on presenting your own point.

 Move on with the discussion. In some cases, it can be beneficial to simply drop a certain point
and move on with the discussion. This might be the case, for example, when it’s clear that the
current line of discussion isn’t going anywhere given the evasion of the burden of proof, but you
believe that other parts of the discussion may be productive.

 Leave the discussion. In some cases, the best solution might be to simply leave a discussion
entirely. This might be the case, for example, when it’s clear that the other person isn’t going to
support any of their claims, and that consequently the discussion has no value for you.

B. The Presumptions
(SOURCE: Anon. (n.d.). Presumption & Burden of Proof in Debating. https://educationalresearchtechniques.com/2019/04/26/presumption-
burden-of-proof-in-debating/; Argumentation and Debate Critical Thinking for Reasoned Decision-Making 12th Ed. by Austin J. Freeley and
David L. Steinberg at
http://staff.uny.ac.id/sites/default/files/pendidikan/Rachmat%20Nurcahyo,%20SS,%20M.A./__Argumentation_and_Debate__Critical_Thinking_f
or_Reasoned_Decision_Making.pdf)

In debate, presumption is a predisposition favoring a given side in a dispute. It describes the psychological
predisposition of a listener or decision maker. The opponent or negative team/side is responsible for
opposing the proposition. The team holds the presumption in the debate. The presumption is the opposite of
the burden of proof. Its role or responsibility is to defeat the proposition. It is generally agreed that the best
manner in which to proceed is to present a logical negative case which refutes or contradicts the affirmative
and supports the status quo.
Presumption may be viewed from two perspectives:
 Judicial presumption always favors the status quo or keeping things the way they are currently. Small
changes can be made but the existing structure is not going to be different. In debates that happen from
the judicial perspective, the affirmative side that has the burden of proof must show that the
benefit of change outweighs the status quo.

 The policy form of presumption is used when change is necessary to the status quo. Example would
be replacing an employee. The status quo of keeping the worker is impossible and the debate is now
focused on who should be the replacement. A debate from a policy perspective is about which of
the new approaches is the best to adopt.
Additional readings: Burden of Proof and Presumption in Lincoln-Douglas Debate: A Call for Reform by
Minh A. Luong at https://debate.uvm.edu/NFL/rostrumlib/ldbofpluong1095.pdf.
C. The Burden of Refutation

The affirmative side and the negative side have a burden of refutation — they have the obligation to refute, or
respond to, opposing arguments. Burden of refutation referred to as the burden of “clash” rests on the
advocate whose case is weakened by an argument advanced by an opponent. The advocate must refute that
argument or suffer damage to the case.

Example: In Richard Roe’s case, if Roe introduces evidence to establish that he was in New York at the
time of the robbery, the prosecution has a burden of refutation. That is, the Chicago district attorney
must refute that evidence or Roe will go free.

Similarly, in debate, the affirmative must refute the negative’s argument or face a serious loss.