In debate, we usually use the word “proof” to describe evidence - quotes from experts, statistics, examples, and so on. But proof can take many forms.

Proof is a reason to adopt a positive belief.

The most important part of any proof is the logical support. Some arguments - known as “presses” - depend entirely on logical proof, without any need for evidence. For example, if you accept your opponent’s definition but then argue that they’re not topical by their own standard, that’s a topicality press.

Burden of Proof is the responsibility to provide sufficient reason to believe positive claims that you introduce.

Or, put another way: Burden of Proof is the responsibility to provide enough support for your claim that Preston can support it.

One of the most common mistakes people make when talking about presumption is saying that it only applies to the affirmative. It’s guaranteed to apply to the affirmative because presumption applies to the resolution. But the negative is almost certain to make positive claims of their own, and those will require evidence.

Resolved: The affirmative’s new friend Michael is great.

Preston: I have never met Michael; I presume that this is untrue.

Aff: Michael risked his life to save me from a burning building.

Preston: Wow! Michael is great.

Neg: Are we sure that Michael isn’t a serial killer?

Preston: Are you saying he is a serial killer? Because I would need proof of that.

Neg: I’m just saying: the affirmative has never proven that he isn’t one.

Preston: You said killer. The burden of proof is on you. Right now, I don’t believe that he is a killer.

Aff: He definitely isn’t .

Preston: Since that’s a positive belief, it’s different from what I was presuming. I’ll need proof of that, too.

Aff: Here’s a copy of his recent psychological evaluation that grades him in the 99th percentile for empathy.

Preston: I’m convinced! I’ll move from the non-positive “I don’t believe that Michael is a killer” to the positive “I believe that Michael is not a killer.”

Neg: Aren’t those the same?

Preston: No. My positive belief puts the affirmative in a much better position on this issue.

Neg: Well, we reviewed the evaluation, it’s actually for someone named Evan.

Preston: Good catch! I’m throwing out the evaluation. And sadly, I no longer have any reason to hold this positive belief about Michael.

Neg: So did we win?

Preston: No. I still don’t think he’s a killer. I just don’t think he’s not a killer, either. He’s just some person who saved the affirmative from a burning building. My only reasonable conclusion based on the available information is that he is great.

Neg: Proving things is hard.

Preston: I know buddy, I know. You still lose the round, though.

Burden of Proof applies equally to everyone.

Does that mean everyone needs to present evidence for every single thing they say? If only it were so simple.

Next week, we’ll introduce you to Proof Matching - a new term in Omni theory. Stay tuned.