Jimmy Akin

The burden of proof is one of the more abused concepts in apologetics today. Apologetics discussions are filled with arguing about the burden of proof, whether it has been met, and—most importantly—who has it.

The Internet is buzzing with such apologetics discussions right now. Yet many of these discussions—particularly concerning who has the burden of proof—are a complete waste of time.

There is a simple rule to tell you who has the burden of proof in a discussion. Unfortunately, most who get into disputes over which side has the burden of proof don’t know what this rule is, and an enormous amount of time is wasted on trying to figure it out.

Burden of Proof in Law and Debate
Most people are familiar with the concept from the legal principle that someone on trial in the United States is “presumed innocent until proven guilty.” The burden of proof is the requirement that the prosecution must meet in overcoming the presumption of innocence.

The burden of proof is a concept also employed in debating, where the standard principle is that the side that “takes the affirmative” must shoulder the burden of proof. In other words, the side in a formal debate that argues that you should believe or do something must produce reasons why.

As a result, the burden of proof changes depending on how you phrase the resolution. To use an X-Files analogy, “Resolved: Aliens exist” will place the burden of proof on Agent Mulder; “Resolved: Aliens do not exist” will place it on Agent Scully. The burden falls to whichever debater agrees with the resolution.

This situation would be much more complicated if the opposing debaters were expected to both knock down the affirmative team’s arguments and prove an alternative position. For example, if folks were debating the resolution “Christianity is the true religion,” it could get quite muddled if those taking a negative position were expected to both knock down the Christian arguments and prove the truth of a different religion.

That kind of muddle is judged too much for the kind of formal debating that high school and college debate teams engage in. But it is precisely the kind of muddle found in apologetics.

Burden of Proof in Apologetics
Apologetics discussions are frequently like formal debates without the formal part. In other words, debating without the rules.

If one group in a discussion accepts (or can be made to accept) the burden of proof, then the outcome of the discussion can be more easily ascertained. If you are not part of the group that has the burden, then in theory your job is easy: You simply have to knock holes in the other side’s arguments. If you succeed in doing so, you win, and your opponent must acknowledge that he was wrong and convert to your viewpoint.

If only it were so easy.

In a debate, who has the burden of proof is arbitrary. It depends on how the resolution is phrased. But in a trial, it is clear who shoulders the burden: the prosecution. Horrendous social consequences would result if the reverse were true. Human experience has shown that tyranny would result if people in court were presumed guilty.

The courts, therefore, have a rational reason for placing the burden of proof on one side rather than the other. But what about apologetics discussions? Do they have a rational way to set the burden of proof with a particular side?

It would be nice if they did. To place the burden of proof on your opponent in such a discussion would make it easy for you. As a result, many apologists, regardless of the issue, seek to lay the burden on their opponents and, when challenged, try to come up with rational reasons for this.

Most of the reasons that you hear are lousy.

Atheism and the Burden of Proof
Take the case of atheists debating the existence of God. They will commonly assert that theists rather than atheists must bear the burden of proof, that it is they who must show reasons that God exists, not the atheists who must show reasons that he does not.

They might justify this claim by saying that theists should bear the burden of proof because everyone who has a belief—regardless of what the belief is—should have a reason for it. This argument has some appeal. There seems to be a basic human intuition that we ought to have reasons for our beliefs.

But it is a lousy argument for showing that theists rather than atheists should have the burden of proof. The atheist also has a belief (namely, “God does not exist” or “There are no gods”), and he too should have a reason for his belief. The atheist should share the burden of proof to the same extent as the theist.

Some atheists have asserted that the burden of proof is on the theist because he asserts something positive—namely, the existence of God. The atheist, by contrast, asserts something negative: the non-existence of God. It is “positive beliefs,” this argument goes, that require one to shoulder the burden of proof.

But why should this be so?

After all, they are logically equivalent. “X exists” and “X does not exist” are convertible. Negate them and they switch places. They can be plugged into the same logical formulas.

Let me give a more concrete example: Why should the claim “I have a brother” be held to a higher standard of proof than the claim “I do not have a brother”? Surely, if I make either claim I should have a reason for it. But isn’t the memory that I did grow up with a brother on the same footing evidentially as the memory that I did not grow up with one? Wouldn’t the fact that a brother is listed in the birth records for my family be on the same level as the fact that one is not listed in them? Why should a claim of existence require more evidence than a claim of nonexistence?

The evidence used to argue the existence or nonexistence of a brother is the same: my own memory, the testimony of relatives and family friends, what is recorded in birth and medical records. What this evidence says should settle the matter. I don’t have to produce any extra evidence to argue that a brother exists than to argue that one does not.

Sometimes to defend the claim that they should not have the burden of proof, atheists appeal to a concept known as “the universal negative.” A universal negative is a claim that nothing of a particular sort exists. For example, “There are no unicorns” or “There is no present king of France.”

The argument is that no one should be asked to prove a universal negative because it is impossible to do so, and nobody can be required to do the impossible.

To prove a universal negative, one would have to have knowledge of the entire universe so that one could verify that the thing in question does not exist, and nowhere in the universe is a unicorn and nowhere in the universe today is a man who is the king of France.

This argument is unfair because it raises the burden of proof to a new level. No longer does it concern providing reasons for believing that the thing in question exists. It now requires universe-spanning, exhaustive proof of it. This is an important distinction.

It is easy to provide reasons that one should not believe in unicorns (e.g., they are claimed to be corporeal beings but you have never seen one with your own eyes; you can’t find photos of them in biology textbooks; biologists don’t hold them to exist; most people regard them as fictitious). It is another thing to scan all of creation and prove the point in exhaustive detail.

Similarly, one could ask the atheist to produce other reasons to think that God does not exist (e.g., most people believe God to be a fiction; there seem to be logical contradictions in the idea of God; there is an absence of any evidence of miracles in history; the universe does not appear to show traces of intelligent design). The atheist doesn’t have to scan the universe in exhaustive detail to offer such reasons. He simply has to appeal to the evidence at hand, and if the evidence at hand doesn’t allow him to make such claims, then it doesn’t offer us reasons to disbelieve in God.

Ultimately, the appeal to “universal negatives” doesn’t work, because in an ordinary discussion people don’t expect their opponents to prove their beliefs by scanning the whole universe. All they want them to do is look at the evidence that is available and make an assessment based on that.

Protestantism and the Burden of Proof
Trying to shift the burden of proof to one’s opponents is a tactic not limited to atheists. Protestant apologists also try it, and on a wide variety of subjects. One of these is the principle of sola scriptura—that we should form our theology “by Scripture alone.”

An argument that is sometimes used to defend this principle is reminiscent of the atheist’s “universal negative” argument: “I shouldn’t be asked to prove that we should do theology by Scripture alone because to show this I would have to prove a universal negative, and nobody can do that. I can’t scan the universe and show that there is no other source we should do theology by, so I’m entitled to conclude that there is not.”

This argument fails for the same reason that the atheist’s argument does: Nobody is being asked to scan the universe. All one has to do is look at the evidence at hand and see whether it indicates that we should do theology by Scripture alone.

What does the evidence at hand include? This is something we could argue about. In fact, it would be interesting to argue about the criteria by which we can know that something is a source to be used in theology. Nevertheless, in the Catholic-Protestant controversy it at least could be agreed upon that Scripture itself is relevant to the question of how we do theology. If it indicates that we should do it one way, then we should. If it indicates we should not do it a particular way, then we shouldn’t.

Things begin to look bad for the Protestant case, then, when we find Scripture saying positive things about the role of Tradition in the Christian life (cf. 1 Cor. 11:2; 2 Thess. 2:15; 3:6; 2 Tim. 2:2). Things look even bleaker when it is realized that there is an absence of verses that teach Scripture alone.

The coup de grace comes when one realizes that if sola scriptura were true then there would have to be such verses. If all principles of theology must be established by Scripture alone, and sola scriptura is a principle of theology, then it must be established by Scripture alone. If it can’t be, then it is shown to be false by its own test.

Realizing this, one discovers that the advocate of sola Scriptura doesn’t have to prove a universal negative; he has to prove a “particular positive”—namely, “Scripture teaches sola scriptura.”

It is the inability to prove this that motivates Protestant apologists to appeal to the universal negative argument in the first place.

The Rule
Sola scriptura is not the only issue on which Protestant apologists will attempt to place the burden of proof on Catholics. It is a general rule that, whenever an apologetics discussion begins, both sides will try to place the burden of proof on each other. That’s where the confusion and the time wasted begin.

But, as I indicated, there is a simple rule to tell which side has the burden of proof.

I recently pointed out this rule in an e-mail discussion I was having with a Protestant seminary professor regarding the much-discussed ossuary of James and what implications it may or may not have for our knowledge of the Holy Family. During the course of the exchange, the professor asserted to me that I would have to shoulder the burden of proof if I wanted to maintain that Mary was a perpetual virgin.

My response was simple: Yes, I would . . . if I were trying to convince you of that point. Whenever two people disagree and one wants the other to change his view, then the person advocating the change always has to shoulder the burden of proof.

In our discussion, I wasn’t trying to show him that Mary was a perpetual virgin. That’s what I as a Catholic believe, but I wasn’t trying to get him to change his mind on this point. I was simply trying to get him to acknowledge that the ossuary, if genuine, did not show that James was a biological son of Mary (a point that he grudgingly and tacitly conceded).

Had I been trying to bring him over to the Catholic view on Mary’s perpetual virginity, then I would indeed have to shoulder the burden of proof.

Any time someone wants us to change a belief we have, he has to give us reasons that we should do so, and in that he takes on the burden of proof.

The trouble arises in apologetics discussions when the two sides in the discussion are trying to mutually convert each other. That’s normal in such discussions, but it results in their being two cases argued simultaneously. In an apologetic encounter between a Protestant and a Catholic, the issues being argued frequently are “Protestantism is true” and “Catholicism is true.” On the first issue the Protestant has the burden of proof, and in the latter the Catholic does.

Such discussions will always go on because it’s human nature for each side in a discussion to want to bring the other around to his own point of view. But recognizing that the burden of proof does not simply rest with one side or the other—recognizing the true complexity of the discussion—can save an awful lot of time and emotional energy that otherwise would be wasted in wrangling over who has to prove what to whom.

Bottom line: If you want to prove something, it’s up to you to prove it.