A prioris are a bogeyperson in debate—they’re often objects of criticism in judge paradigms and debate theory articles. They’re sometimes even used as a character smear. However, they’re not very well understood. Many so-called ‘tricky’ arguments are lumped into the a priori category with little attention to what makes an a priori an a priori. This article sets out to define the a priori, delineate between two primary types, and discuss response strategies. I hope this adds some clarity and sets groundwork for future discussions of the a priori.

An a priori argument is one that (i) purports to prove the truth or falsity of the resolution, (ii) involves entirely deductive proof and (iii) precludes or in some way trivializes the usual contention-level debate. Beyond this definition, we can divide a prioris into two types: Type 1 a prioris prove that any resolution is tautological (always true) or unsatisfiable (always false), and Type 2 a prioris prove that this particular resolution (or this type of resolution) is true or false.

Type 1 A Prioris

Type 1 a prioris usually make semantic or logical arguments that have little to do with the content of the resolution. Take the following examples:

  • Argument 1: Trivialism (the logical theory that all statements are true) is correct, which means the resolution is true.
  • Argument 2: Wittgenstein’s/Kripke’s rule-following paradox is true, which means it’s impossible to interpret or assign meaning to the resolution, so it cannot be affirmed.

These are classic examples of a prioris. Both prove the resolution true or false, are entirely deductive, and preclude usual contention debate. To show this last feature more concretely, imagine Argument 1 vs. a disad showing that the plan leads to extinction. The disad is precluded by trivialism because it states that all statements/propositions are true, so the resolution is not even subject to empirical disproof by pointing to a high probability of nuclear war.

Turning an a priori is more complicated than turning most debate arguments. The normal way to think of a turn is that when someone makes an argument of the form “X increases Y, which is good,” the link turn in response is “No, X decreases Y” and the impact turn is “No, Y is bad.” However, this model doesn’t easily accommodate responses to Type 1 a prioris. Because they are deductive, they are not susceptible to a normal link turn about a causal relation (e.g. the plan leads to nuclear war, PICs increase education, etc.). And because they are generally semantic/logical, they are not susceptible to a normal impact turn involving a normative claim.

However, we can conceive of Argument 1 as having a link, “Trivialism is correct,” and an impact, “the resolution is true.” While there is no obvious link turn in the area, since “Trivialism is incorrect” isn’t offense, there is an impact turn of sorts. The neg could say something like “Trivialism means the negation of the resolution is true” or “Trivialism makes debate about the resolution meaningless, so negate it.” Similarly, we can conceive of Argument 2 as having a link, “The rule-following paradox is true,” and an impact “the resolution cannot be affirmed.” The aff could impact turn by saying something like “Negating a statement requires rule-following, which is impossible, so you cannot prove the resolution false.” Admittedly, neither of these arguments is particularly persuasive, but each proves the possibility of an impact turn.

What’s important to note too is that the turn itself is an a priori – it’s a deductive proof/disproof of the resolution that makes contention debate irrelevant. Turning an a priori can grant what looks like a reciprocal advantage to the responder. There is often no additional requirement for the Type 1 respondent to forward a new paradigm or set of aff/neg burdens.

Type 2 A Prioris

Type 2 a prioris generally make arguments about the specific language or concepts in the resolution, such as ought or moral obligation. Take the following examples:

  • Argument 3: Moral skepticism is true, which means all ought statements are false.
  • Argument 4: To say X ought to do something requires that X has a unified intent; the United States as a group has no unified intent, so the resolution is false.

These are also classic examples of a prioris. Both prove the resolution false, are entirely deductive, and preclude usual contention debate. One difference between Type 2 a prioris and Type 1 a prioris is that Type 2 are not as preclusive since they often interact more heavily with other arguments in the round. For example, a consequentialist framework may not have a single argument that responds to trivialism, but it might have an argument in moral epistemology that takes out skepticism/Argument 3. It may not interact with Kripke’s rule-following paradox but contain some claim about government obligations that takes out Argument 4. Still, Type 2s still meet the preclusive prong of the definition since they do often ask prior questions to the usual framework-contention pairings. “Do we have any moral obligations?” precludes the question “Are our moral obligations tied to the effects of possible actions we might take?” Answering the first question “No” strongly suggests the answer to the second is also “No.”

Type 2 a prioris are also distinct in that the impact turn strategy discussed with regard to Type 1 a prioris is largely unavailable. If the link is “Moral skepticism is true,” and the impact is “all ought statements are false,” it’s hard to see what the impact turn should be. There are what I’ll call ‘parallel’ arguments the aff can make, that “all ‘ought’ statements are true,” but this isn’t so much a turn as it is a distinct argument that states the opposite. It doesn’t take the link for granted – that moral skepticism is true – and generate the opposite conclusion, like the impact turns to Type 1 did. Instead, it merely relies on the burden structure that the initial argument constructed. The same can be said for Argument 4. I see no room for an argument that “To say X ought to do something requires that X has a unified intent; the United States as a group has no unified intent, so the resolution is true.” It may be that someone cleverer could come up with the “turn,” but the quality will be far lower than the impact turns in Type 2.

One might think that Argument 3 can be turned by winning permissibility or presumption debates. This is not a turn in the classic sense described above because both the link and impact are conceded. There is an additional premise added: either that moral skepticism suggests the action described by the resolution is permissible or that moral skepticism means the judge should presume aff or neg. Making one of these arguments is an additional burden for the aff, so neither is an impact turn.

A Prioris vs NIBs vs Means-Based/Side-Constraint NCs

The examples I’ve given here demonstrate that a prioris can be a necessary-but-insufficient burdens to varying degrees. Type 2 a prioris are far more likely to be NIBs since they’re less likely turnable than Type 1 a prioris. The fact that an argument is a priori does not automatically make it a NIB. There may still be reciprocity concerns stemming from their preclusiveness, but we should distinguish that worry from simplistically calling all a prioris NIBs.

My examples also demonstrate the difference between Type 2 a prioris and Means-Based/Side-Constraint NCs. Take the Libertarianism NC for example. Unlike Argument 4 above, the Libertarian NC likely admits the possibility of the government possessing a positive obligation; most will admit that the government has some basic positive duties, e.g. to provide due process in criminal court or protection from outside threats. The aff can create offense by isolating the reasons behind those positive duties and using them to justify the plan/resolution. These arguments often take the form of the ‘hindering a hindrance’ idea or other positive obligations. Thus, an NC is less likely a NIB than a Type 2 a priori. Further, while proving the resolution false and perhaps using deductive proof, the Libertarianism NC differs from Argument 4 on preclusiveness (a priori criteria iii). It does not preclude all usual contention-level debate since an aff could use its contention to prove a state’s positive obligation to affirm.


Although the myriad common a prioris are often regarded as identical in form and content, there are a few important substantive and structural differences that separate them. While many people engage by jumping to a higher flow (whether through theory or a role of the ballot argument), better understanding a prioris might make it easier and more strategic to engage them on their own merit.

End Notes

[1] Thanks to Bob Overing for his edits and feedback throughout.

Noah Simon | Guest Contributor

Noah is the sole debater for Crossroads School (CA), where he has earned a career total of 10 bids. In his junior year, he championed the Voices Round Robin, reached finals of the Mid America Cup, the Valley Round Robin, the Voices Invitational, the Battle for LA Round Robin, and cleared at TOC. He was also top speaker at College Prep and Loyola. In addition to his debate successes, Noah is an accomplished classical pianist.