During a rebuttal speech, the debater presents counter-arguments which refute the claims of the opponent. These arguments have two aims. First, to directly attack the basis or claims of the opponent's case as presented in the constructive speeches and second, to answer any attacks the opponent has made against your case. Part one of this topic will focus on attacking the opponent's case and part two on answering attacks against your own case.
Attacking the Opponent's Case
The opponent's case is built upon a series of claims which should be backed by some kind of evidence. The claims will lead to the conclusion the opponent wants the judge to take. The claims will usually be built upon premises which serve as the logical basis for the claim. Some claims may be impacts (advantages, benefits, disadvantages, harms, etc) which are the consequence of some action or condition. Attacking a case means, refuting the premises and claims, grounds or links. Effective attacks are comprised of pointing out failures of the logic leading to the conclusions, presenting evidence which directly refutes evidence in the opponent's case, turning the arguments by showing either the causation does not lead to the claimed impact or the claimed impacts actually lead to other impacts with are detrimental to the opponent's case.
Attacks in the Constructive
I include here, the idea that the negative (or second speech) can attack the opponent's case directly and more or less spontaneously as part of the negative constructive speeches. This is done by reading disadvantages. Since new arguments are not allowed after the constructive speeches, these kinds of attacks (especially in Policy debate) are made immediately as part of the constructive. (For more on this topic, see Attacking With Disadvantages, below). Another form of attack embedded in the constructive is to include preemptive arguments against attacks that are likely to be brought up later by the opponent. These kinds of speeches blur the nice neat lines between what is a constructive and what is a rebuttal, but because they can be effective rebuttal strategies, I include them in the topic.
Attacking the Premises
Many times a claim is built upon premises which are presumed true either because we all agree they are true or because the evidence proves they are true. Once the truth of the premises are established the argument can be structured into a logical conclusion. For example: Premise 1 - All illegal immigrants should be deported. Premise 2 - Xavier is an illegal immigrant. Conclusion - Xavier should be deported. If one assumes premise 1 and premise 2 are universally true, there is no other conclusion for Xavier. Obviously, if you can refute the truth of the premises by either showing that NOT all illegal immigrants should be deported or Xavier is NOT an illegal immigrant, the opponent's claim that Xavier should be deported is inconclusive or not true. Often a universal premise is preceded by a statement like ALL, EVERY, EACH, etc. These should be red flags for the debater to attack the universality of the premise. For example, if you can show that most illegal immigrants should be deported but not ALL, one can no longer conclude, based on the premises supplied, that Xavier should be deported. Sometimes the logical conclusions drawn by the opponent are simply incorrect or inconsistent. For example: Premise 1 - the U.S. has always provided aid to poor nations. Premise 2 - Somalia is a poor nation. Conclusion - the U.S. should provide aid to Somalia. The first premise is assumed to be universal but it may possible to refute this if you can show examples of poor countries not being aided by the U.S. But there is another glaring problem with the first premise. It is an appeal to tradition (argumentum ad antiquitatem) because it assumes since something was true in the past, it is also true now. This is a logical fallacy which is easily refuted.
Attacking the Grounds
The grounds for a claim are the proofs the claim is true. In debate this usually means the evidence and the warrants which link the evidence to the claims. There are three principle ways to attack the grounds:
- Refute the evidence with more recent evidence which draws a different conclusion.
- Show the opponent's evidence does not link or apply to the conclusion.
- Refute the validity of the evidence by showing it is flawed in its methods (usually applicable to statistical evidence), or the source is biased or otherwise not credible.
It's quite common that certain evidence may be superceded by more recent evidence and most judges will usually conclude the more recent evidence is more valid. So if you have a more recent study or statistic which refutes a similar piece of evidence given by the opponent, then use it. Sometimes the opponent's evidence or warrants may not be applicable to the claim or premise trying to be proved. The opponent may simply be misinterpreting the evidence and so you should reveal these kinds of flaws to the judge. Finally, the source of the evidence should be considered even though in some types of debate, such as policy, the sources are rarely questioned. Sources can be biased or worse yet just plain wrong in how they have reached their conclusions and so these flaws can also be attacked.
Attacking With Disadvantages
A good strategy of attack for a debater is to show how adoption of the opponent's position results in harms or undesirable consequences . In policy debate, these kinds of attacks are called disadvantages or D.A.s. An effective DA must be predicated on some aspect of the opponent's case. In other words, something the opponent's case advocates will result in the DA. There must be a link from the opponent's case to the DA you wish to promote. Next, the disadvantage must be result solely as a consequence of the action or condition advocated in the opponent's case. In other words, if the disadvantage will occur without adopting the opponent's position then there is no reason not to support the opponent's position. And finally, and this is most obvious, there must be an impact or consequence which is the thing that makes it a disadvantage in the first place. A properly constructed disadvantage, will answer the question, "why is it the harm will not happen in the status quo but only if the opponent's position is adopted?" and it will answer the question in the impact, "how bad will it be?".
Things to Avoid When Attacking
Be sure to always attack the opponent's case and never the opponent's character, motives, intentions, or such. Always focus on attacking the elements of the case no matter how intense the round may become.
Try to attack the claims on the opponent's case in the same sequence in which they were presented. This is commonly referred to as line-by-line refutation. It makes it easier for you (and your partner) to enure you have attacked each point and it helps the judge to follow the flow of the attack and anything you can do to help the judge follow your claims works to your advantage.
Do not try to refute everything. Selectively drop some points if necessary. It is not always to your advantage to attack every claim on the opponents constructive. It is best to attack the most significant arguments letting the less important points flow through to later speeches. The opponent may claim you dropped these arguments but it may not matter if your own claims have more of an impact on the judge's decision than the few relatively minor things you may have dropped. Knowing what to drop and when to drop it depends on the dynamics of the round and but you should consider it a viable strategy to allow time to heavily refute the opponent's strongest arguments while defending your own.