The burden of proof (called in Latin onus probandi) is the obligation to provide sufficient supporting evidence for any arguments that you make. For example, if a politician claims that a policy they want to implement is guaranteed to lead to a number of positive outcomes, then that politician has a burden of proof with regard to this statement, meaning that they need to back it up with supporting evidence.

A concept that is intrinsically related to the burden of proof is the burden of proof fallacy. The burden of proof fallacy is a logical fallacy that occurs when someone claims that they don’t have a burden of proof with regard to their own arguments, or when someone attempts to shift their own burden of proof to someone else.

For example, consider a situation where, during the course of a media interview, a politician is asked to justify a policy that they want to implement. If the politician asks their interviewer to justify why the interviewer thinks that policy shouldn’t be implemented, the politician is committing the burden of proof fallacy, because they’re not providing evidence which supports their stance, and because they’re attempting to shift their own burden of proof to someone else.

Since the burden of proof and the burden of proof fallacy are concepts that often play a significant role when it comes to conducting any kind of discourse, it’s important to understand them.

As such, in the following article you will first learn more about the burden of proof in general, and about when exactly people have a burden of proof with regard to statements that they make. Then, you will learn about the burden of proof fallacy, see some examples of when it occurs, and understand what you can do in order to counter people who use it.

The burden of proof

The importance of the burden of proof

The burden of proof is one of the most important guiding principles which are used in order to help people conduct discussions and resolve disputes in a proper manner. Specifically, each person a burden of proof with regard to their own claims, so that if they want their claims to be accepted by others, they must provide proof which supports those claims, either as part of their original argument, or in response to their opponent’s questions.

Examples of the burden of proof

Examples of situations where someone has a burden of proof include the following:

If someone claims in a debate that their theory can explain a certain natural phenomenon, then they have to provide evidence which supports this claim.

If someone is suing someone else for damages, then the person who is suing has the responsibility to prove that the other person is responsible for the damage that they experienced in some way.

If a company claims that the medication they developed is safe and effective, then they have to prove it using clinical data.

Who has a burden of proof

In general, a person has a burden of proof with regard to any arguments that they make, which means that they have to provide sufficient evidence in order to support those arguments.

When it comes to discussions, each side has to provide proof which supports the arguments that they make, and the other parties involved in the discussion may ask critical questions about those arguments, and ask their opponent to provide more supporting evidence. This means that the burden of proof can continuously shifts between the discussants, so that different people are expected to provide supporting evidence at different stages of the discussion.

However, not every statement that a person makes carries with it a burden of proof. In general, there are three main types of statements, some of which require a burden of proof, and some of which do not:

An assertion carries a burden of proof. If you clearly assert that a certain statement is true, then you have a burden of proof to demonstrate that this is indeed the case, meaning that you must either prove that your assertion is true, or retract it.

If you clearly assert that a certain statement is true, then you have a burden of proof to demonstrate that this is indeed the case, meaning that you must either prove that your assertion is true, or retract it. A presumption carries a conditional burden of proof. If you ask someone to presume that a certain statement is true, then you don’t necessarily have a burden of proof with regard to that presumption, unless your opponent questions it, at which point you must either prove that your presumption is true or retract it, as is the case with an assertion.

If you ask someone to presume that a certain statement is true, then you don’t necessarily have a burden of proof with regard to that presumption, unless your opponent questions it, at which point you must either prove that your presumption is true or retract it, as is the case with an assertion. An assumption carries no burden of proof. If you simply assume that a certain statement could be true, but don’t claim that this is necessarily the case, then you have no burden of proof. However, note that if you rely on your assumptions too much in the argument, or if your assumptions are perceived as too unlikely, they will end up weakening your argument, especially if they are challenged by your opponent.

Of course, note that all this is also applicable in situations where you assert, presume, or assume that something is false, rather than true.

Finally, keep in mind that in many cases, a person might make an assertion or a presumption which are entirely unsupported, and then refuse to retract it, even when prompted to do so by the other discussants.

In theory, such statements should be ignored from a logical perspective, since the person who made them failed to provide the necessary proof required in order to support them. This notion is exemplified in Hitchens’s razor, which was formulated by author and journalist Christopher Hitchens, and which states that:

“What can be asserted without evidence can be dismissed without evidence.”

In practice however, situations where someone fails to provide necessary proof are complicated, and it’s often up to the other party or arbitrators to determine how to proceed. We will soon see some suggestions on how to deal with such cases, in the section on the burden of proof fallacy.

Special cases with regard to the burden of proof

According to some philosophical views, certain assertions and presumptions are privileged, meaning that they are strongly supported and well-established enough that the person who believes them needs to defend them only in the face of what is perceived as a valid challenge.

This means, for example, that if a person supports the prevailing consensus in some field, which has already been proven to be true in the past by others, then that person needs to reply to challenges against their view only in cases where the challenger has first fulfilled their own burden of proof to a reasonable degree.

For instance, a scientist might refuse to engage someone who claims that the Earth is flat, unless that person can provide some compelling evidence in order to challenge the current scientific consensus on the topic.

Of course, this raises the issue of determining what constitutes a privileged proposition, and in some cases, claiming that a certain stance is privileged carries with it a burden of proof in itself. For example, in the case of arguing against those who believe in a flat Earth, one way to demonstrate the consensus regarding the shape of the Earth is to prove that many different scientific authorities agree that the Earth is not flat, without getting into more details beyond that.

The concept of privileged propositions plays an important role in cases where people attempt to bombard someone else with disingenuous questions, in an attempt to undermine their stance. Though asking questions is, in general, a valid thing to do in a debate, it can become problematic when one side is attacking the other with a non-stop stream of questions, since there is usually asymmetry between the ease of asking questions compared to the relative difficulty of answering them.

For example, consider the case of the Gish gallop, which is a debate technique where someone attempts to overwhelm their opponent by mentioning as many arguments as possible, with no regard for the quality of these arguments. In some cases, the person using the Gish gallop might bombard their opponent with questions, in order to force them to defend their stance, by placing most of the burden of proof in the discussion on them.

In such cases, it can be valuable to shift the burden of proof back to your opponent in order to get them to at least justify their line of questioning before answering those questions. However, it’s important to not simply do this in order to evade your own burden of proof, but rather in order to ensure that the questions which are asked contribute to the discourse, rather than hinder it.

Finally, note that the concept of privileged propositions is controversial, and should be treated as such. Accordingly, while the present article provides an explanation of this concept and of how it can be implemented, this does not mean that it advocates for its use. The question of whether or not certain propositions should have a privileged status remains open for debate, as does the question of which propositions should have a privileged status, and in what circumstances.

Note: a related concept is the Sagan standard, which suggests that “extraordinary claims require extraordinary evidence” (a concept abbreviated as ECREE). This signifies that the more unlikely a certain claim is, given existing evidence on the subject, the greater the standard of proof that is expected of it.

The burden of proof in law

The burden of proof plays an especially important role in the legal context, where it is assigned by the judge to different parties in a trial, and where a party’s ability to successfully meet this burden is determined by the judge and jury, as are the consequences of success or failure.

In this context, there is often a distinction between the burden of production, which is the burden of presenting necessary evidence to the judge or jury, and the burden of persuasion, which is the burden of convincing the judge or jury that your argument is true, in light of the evidence that you presented.

The nature of the evidence that people must produce and the degree to which they must persuade the judge and jury also vary in different situations.

For example, in criminal cases, a prosecutor might have to prove their accusations “beyond a reasonable doubt”. Conversely, in civil cases, a plaintiff might have a more lenient standard of proof, such as the standard of “preponderance of the evidence”, which is the requirement that, based on the available evidence, it’s more likely that the claim at hand is true than not true.

The burden of proof fallacy

Understanding the burden of proof fallacy

As noted above, the burden of proof fallacy occurs when someone claims that they don’t have a burden of proof with regard to their own arguments, or when someone attempts to shift their own burden of proof to someone else.

For example, if someone believes in ghosts, the burden of proof rests on them when it comes to showing that ghosts exist. Accordingly, it’s fallacious to shift the burden of proof to others, by claiming that no one has disproved the existence of ghosts or by asking someone else to prove that ghosts don’t exist.

The burden of proof fallacy and falsifiability

People who use the burden of proof fallacy often make claims that are not falsifiable, meaning that they can’t be proven wrong, and then ask others to disprove those claims, a task which is inherently impossible.

A common example which is used to illustrate this concept is called Russell’s teapot, as it was proposed by philosopher Bertrand Russell:

“Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense.” — From ‘Is There a God?’ (1952), by Bertrand Russell, as cited in ‘The Collected Papers of Bertrand Russell’, Volume 11 (1997)

In short, Russell’s argument is that if he were to suggest that there is a teapot revolving around the sun, nobody would be able to disprove this claim, if he was careful to add that the teapot is too small to be revealed by our most powerful telescopes, or by any other means of observation that we might have.

Essentially, Russell’s point is that a claim should not be taken as true simply because others are unable to disprove it, especially in cases where the claim is phrased in a way that makes the task of disproving it impossible.

The important thing to remember with regard to the connection between the burden of proof and falsifiability is that when a person makes a certain claim, the burden of proof lies with them to prove it. They cannot transfer this burden of proof to others by saying that their claim is right unless proven otherwise, especially in cases where their claim is impossible to disprove in the first place.

Examples of the burden of proof fallacy

There are many different ways in which people can use the burden of proof fallacy. For example:

Marketer: our new diet pills are guaranteed to help you lose weight. Interviewer: are they safe though? Marketer: do you have any reason to think that they’re not?

The problem here is that the burden of proof lies with the marketer to prove that their pills are safe, even if the interviewer doesn’t have specific reasons to think that they’re not.

Another example of the burden of proof fallacy is the following:

Alex: climate change is a hoax, you know. Bob: really? Where’s the proof of that? Alex: I read it on a website.

In this example, Alex deflects his burden of proof by attributing his statement to a secondary source. While it can sometimes be reasonable to report what a secondary source says on a certain topic, people often use this technique in an attempt to evade their burden of proof, by simply attributing their statements to a different source, without providing any supporting evidence for their statement.

Furthermore, people often combine this technique with the use of vague and ambiguous language, in an attempt to further avoid responsibility for their burden of proof, as in the following example:

Alex: they say that vaccines are bad for you.

Moreover, this technique for avoiding the burden of proof is sometimes combined with denial of commitment, where the speaker attributes the argument that they are making to someone else, while explicitly avoiding taking responsibility for that argument. For example:

Alex: Jenny says that vaccines are bad for you, and that you shouldn’t vaccinate your kids. Bob: is there any empirical proof that supports this? Alex: I’m just telling you what Jenny says.

Here, Alex doesn’t take direct responsibility for his statements, but the way in which he phrases them shows implicit support for this incorrect stance. By doing this, Alex conveys his stance on the subject indirectly, without committing to it in a way that would require him to provide proof of his implicit assertions.

While it can be reasonable to make a statement that relies on the authority of others in some cases, this should be done carefully, and in a manner that avoids relying on fallacious reasoning.

Specifically, it can be reasonable to use someone else’s opinion as supporting evidence in order to satisfy your own burden of proof, as long as you acknowledge what you are doing and justify why their opinion on the topic is relevant, while also taking responsibility for the assertions that you made.

Overall, the burden of proof fallacy can appear in various forms, and can be combined with different strategies, such as attributing your statements to a secondary source, or denying direct responsibility for your statements. The one thing that all forms of the burden of proof fallacy have in common is that the person using this fallacy is either avoiding their own burden of proof, or is attempting to shift their burden of proof to someone else.

How to counter the burden of proof fallacy

As we saw above, there are various ways in which people might use the burden of proof fallacy. When you recognize that this had happened, there are three main things that you can do in response:

Call out the use of the fallacy. You can do this by demonstrating that your opponents had made certain claims which have a burden of proof, and that they have failed to provide the necessary evidence which is needed in order to support those claims. Furthermore, if your opponent attempts to shift the burden of proof to someone else, you can point this out too.

You can do this by demonstrating that your opponents had made certain claims which have a burden of proof, and that they have failed to provide the necessary evidence which is needed in order to support those claims. Furthermore, if your opponent attempts to shift the burden of proof to someone else, you can point this out too. Shift the burden of proof back to your opponent. After demonstrating that your opponent has failed to provide the proof which is needed in order to support their claims, you can explicitly ask them to provide the necessary proof, or to retract those claims.

After demonstrating that your opponent has failed to provide the proof which is needed in order to support their claims, you can explicitly ask them to provide the necessary proof, or to retract those claims. If possible, provide counter-proof yourself. Though the burden of proof may rest with your opponent, in some cases it can be beneficial to simply provide proof which supports your own claims and which contradicts your opponent’s claims, even if they have failed to support those claims in the first place. However, remember that a failure to provide counter-proof on your part does not necessarily constitute evidence that could be used in order to support their stance, especially if their assertions are phrased in a manner that makes them impossible to disprove.

Note that, as we saw earlier, in proper discourse people have a burden of proof with regard to the claims that they make, and they must either defend those claims or retract them, especially when challenged by their opponent.

However, most discourse is not conducted in a proper manner, and there are many cases where people will assert things without any providing any supporting proof, and then continue to stand by their claims even when called out on their fallacious reasoning, and even when presented with evidence which shows that they are wrong.

When this happens, it is generally preferable to try to apply the principle of charity before addressing your opponent’s arguments, and to assume, at least initially, that their use of the burden of proof fallacy is unintentional, since doing so can lead to a more productive dialogue.

Nevertheless, there are cases where it is unnecessary to give people the benefit of the doubt, such as when the other person is clearly using this form fallacious reasoning intentionally, despite knowing that what they are doing is wrong.

When this happens, and especially when it’s clear that the person you are talking to won’t accept that they’re wrong regardless of what you might say, you should reassess the situation, in order to decide whether you should continue the discussion.

In some cases, you might still want to continue the discussion. For example, this might happen if there is an audience watching the discussion, who might be persuaded by your arguments. However, in cases where there is nothing to gain from discussing the topic, you might benefit more from simply disengaging, since the argument won’t lead anywhere anyway.

Summary and conclusions