In a recent post, we explored the Burden of Proof - the responsibility to provide sufficient reason to believe positive claims that you introduce.

Some claims require more proof than others.

This sliding scale is called Proof Weight.

Proof Weight describes the level of support a claim needs for Preston to accept it.

Proof is far from a binary “you read evidence or you didn’t.” Each claim has a unique proof weight, calling for a certain amount of analysis, or statistical support, or expert testimony, or something else. The level of support required for one claim might not be enough to prove another.

Resolved: Donald Trump will not be reelected.

• Preston: That’s believable, but I can’t just accept it without some proof.

• Affirmative: Here’s a national poll showing Biden 7 points ahead of Trump.

• Preston: That’s good enough for me.

Resolved: Kanye West will win the 2020 presidential election.

• Preston: Uh - what!?

• Affirmative: Here’s a national poll showing West 7 points ahead of Biden.

• Preston: Who did that poll? That cannot be right. I am gonna need a lot more analysis and evidence before I take this seriously.

When you provide the amount of support that your claim requires, you have achieved a Proof Match.

Proof Matching: the act of satisfying your Burden of Proof by presenting support that is at least equal to the claim’s Proof Weight.

This is why it’s possible for negatives to win rounds without evidence, even though they make positive claims. You can build a case out of claims with low Proof Weights, scavenging what little support you need from whatever you find in the round - reasonable inferences, contradictions and admissions from the opponent, and so on.

From an epistemological standpoint, common knowledge is a form of proof. You can use presumption to "prove" your own arguments, in the sense that common knowledge and logic are enough to support them. This is the positive version of the toxic "No Evidence" response that untrained negatives use.

Resolved: Canada is a better place to live than the United States.

• Preston: Interesting. I’m open to ideas.

• Aff: Canadians don't pay taxes.

• Preston: Wait, what? That’s way outside common knowledge. What’s your proof?

• Aff: My proof is that I believe it in my heart.

• Preston: That’s not good enough for me. I consider this untrue.

• Neg: Canadians absolutely do pay taxes! I don't have evidence, and neither does my opponent. So how do you decide? Because common sense and common knowledge are on my side.

• Preston: Yeah, I immediately agree with you. I’ll presume that your claim is true.

That's not the same as: "You didn’t have evidence, so you lose." Only once you've provided an alternative claim (like: “Canadians do pay taxes”) can you explain why it falls within presumption.

In the next post, we’ll synthesize all of this into core Omni policy theory. Stay tuned.