Rejoinder Explained

In debate, the affirmative’s burden is to prove the resolution true.¹ This interpretation, then, conversely demands the negative deny this and cast doubt upon the truth of the resolution.² Fittingly, this model of burdens is coined “truth testing,” and functions as a default for many judges across the circuit when adjudicating debates.

The affirmative in debate most commonly presents a plan, or example of desirable resolutional action. Affirmatives often argue that negative arguments attempting to disprove the resolution must disprove the specific plan and not the resolution broadly, claiming the negative must “rejoin the aff.”

In practice, a negative that attempts to go for the agenda politics disadvantage against an affirmative that defends action by the courts would quickly lose to “no link: plan is courts, not congress.”

Given this norm, a common objection to truth testing often goes like this:

If the negative has to prove the resolution false, why can’t they do so in any way they want? Why the plan specifically? Like… why can’t I read a disad proving some other part of the resolution is a bad idea?

The above objections boil down to the titular question we ask today: “Under truth testing, why must the negative rejoin the affirmative?”

The answer to this question lies in what the win condition of the affirmative is and what propositions must be proven for the affirmative to win.

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Affirmation

We know what the affirmative ought to prove the resolution true. The question then becomes, “how do plans do that?”

Traditional knowledge holds that the way plans prove the resolution true is by proving an example of desirable resolutional action. However, the word “example” fails to communicate what’s really going on here.

The plan’s real relationship to the resolution true is one of entailment—for a given plan $p$ to entail the resolution $r$ (visualized as $p\models r$), there must be no world in which $p$ could be true while $r$ is false³. That means the plan’s truth necessarily implies the truth of the resolution.

For example, imagine three propositions:

1. $a$: “Some⁴ ice cream tastes good.”
2. $b$: “Chocolate ice cream tastes good.”
3. $c$: “Sprinkles taste good.”

If it is true that “all ice cream does not taste good” $(\neg a)$, chocolate ice cream can never taste good. Thus, $b\models a$.

On the other hand, it can be true that sprinkles taste good $(c)$ even in a world where “all ice cream does not taste good,” $(\neg a)$ despite the fact that ice cream can have sprinkles on it. Thus, $c/\models a.$

If the affirmative succeeds in proving $p$, and $p\models r$, then, by modus ponens, they have succeeded in proving $r$.⁵ For this article, the set of all topical plans $U=\{p|p\models r\}$.

Let’s formalize this conclusion: The affirmative need only prove any given plan $p$, where $p\in U$, to prove $r$ and win.

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Negation

Now, propositions must be proven true to be taken as such, which means the set of every other plan the affirmative did not defend (which we’ll call $Q$) is false by default. Let’s call one of these other plans $t$—since $t\in Q$, $t$ is false.

Herein lies the answer to our question: a disadvantage to $t$ doesn’t negate $r$ because it simply beats a dead horse; since all of $Q$ (and, by extension, $t$), is trivially presumed false, a disadvantage to $t$ wouldn’t make it any false-er than it already is! Unless the disadvantage equally applies to $p$ (think generic disadvantages to core topic mechanisms), the negative’s missed the boat entirely on the distinct proposition in $U$ which independently proves $r$.

To return to the ice cream example, imagine three propositions:

1. $a$: “Ice cream tastes good.”
2. $b$: “Chocolate ice cream tastes good.”
3. $c$: “Vanilla ice cream tastes good.”

The affirmative in this debate defends proposition $b$, which lies in the set of all flavors of ice cream $f$ alongside $c$ affirming the resolution $a$. A disadvantage to $c$ (say, the vanilla is contaminated and thus poisonous) or any of the other flavors in the set $f$ that are not $b$ would fail to negate the resolution as, uncontested, $b\models a$.

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Affirmative Conditionality

The consequence of allowing the proof of any propositions in $U$ as a sufficient win condition for the affirmative enables affirmatives to garner offense from multiple plans, needing to only win the truth of one to win the debate. Each becomes a Necessary yet Insufficient Burden for the negative to win, which, for some, raises stark concerns over debatability.

However, these objections are not as damning for truth-testers as they may seem.

”That’s just too much for the neg to handle!”

If each plan is topical, the negative should already have preparation against each. If they’re not, go for topicality. Otherwise, it’s their fault for being unprepared.

It’s also reciprocal; each plan takes away time the affirmative could use to develop other plans/advantages, which means negatives should be able to capitalize on the flaws in each.

If the argument is “obscure conjuncts of plans would be unnegatable,” a slew of advantage counterplans, deficits and disadvantages germane to each plan would likely punish such weak internal links.

”They can kick plans to moot the 1NC!”

This has differing implications in LD and policy, but the principle remains the same: the negative can pivot in the NR/block and raise new arguments to answer “new” 1AR offense, which is limited by the fact that these speeches are, in fact, rebuttals, where no new arguments are allowed to be introduced.

If this seems unstrategic for the affirmative, that’s because it is; that strategic cost to each additional plan⁶ balances out whatever skew the negative might experience and serves as a functional limit to how many conditional plans might be advocated.

An additional limit to keep in mind: each plan $p$ must entail $r$ on its own; conjunctions of plans sufficient to entail the resolution would lose to topicality if each conjunct did not entail $r$ (e.g. multiple plans meeting T-substantial, but each individual plan violating it).

”Didn’t they decide debate was ‘case studies’ in the 80s?”

1. Who is “they?” Why are we deferring to half a decade-old models?
2. How on earth is this model predictable?
3. Why does this exclude hypothesis testing? Why can’t the affirmative equally offer multiple case studies in one debate?

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Final Thoughts

This article is definitely imperfect, and may have some objectionable takes. It’ll be updated over time as different dialogues occur, so reach out if you have some thoughts! Once I get the comments section on these pages working, share your thoughts there.

Happy debating!

Footnotes

1. For the sake of this article, we’ve derived this interpretation a priori as constitutive to the format of debate (with which compliance may vary). ↩

2. Interestingly, this does not demand the negative prove we ought not do the resolution. This has implications on negative fiat to be explored in a later article. ↩

3. Joshua Hershey, “Consistency, Entailment, and Equivalence,” skillfulreasoning.com, November 21, 2025, https://www.skillfulreasoning.com/propositional_logic/relations_between_propositions.html. ↩

4. Resolutions have quantifiers too, they’re just implicit instead of explicit. We’ve put “some” here to explicitly quantify for clarity. ↩

5. This happens to be the level at which topicality debates occur. There, the negative and affirmative disagree over whether $p$ entails $r$ based on the rules of grammar and the legal interpretation of what the terms of art in $r$ may entail. ↩

6. This, and a lot of other defenses of affirmative conditionality, sound very similar to the common defenses of negative conditionality. That is on purpose. ↩