Attacking Their Logic

Every argument relies on a lot of hidden (and obvious) assumptions to get to the final conclusion. Identify the premises of each argument and determine whether they are valid or invalid. Think of these premises like dominos – you only have to knock one over in order to take the entire argument down.

This is done in a number of ways:

• There are a number of commonly used jumps in logical reasoning that are completely incorrect– these are called logical fallacies. By knowing a wide range of ones used frequently, you can often point out flaws in their contentions/case. A solid list of fallacies
• You can often target the underlying assumptions made by your opponents when destroying their logic– this is often very useful, as tearing down the baseline foundation of their case is the most efficient and most effective way at stopping them from rebuilding their points.
• One particularly useful debating tactic that helps destroy points is taking something to its logical extreme. Especially if your opponents have based one of their contentions in some kind of principle, you can often extend that further than they have and show how it’s actually ridiculous at heart. They will of course attempt to phrase their points in the most reasonable fashion as possible– try to show the judge they aren’t reasonable at all! Beware of using a slippery slope, though, as this often can lead to that fallacy if you aren’t careful in how you phrase your rebuttal. (If you don’t know what a slippery slope is, look at the list of logical fallacies above!)

Drill

Impact Explanations: Try and convince us why each of the following impacts is the worst possible thing in the world. Write out the argument you are making in a way that maps each step you take towards the conclusion. The goal is to focus on creating a logical chain to the conclusion, and to practice not making major claims without the reasoning to back them up. Afterwards, try to knock down the arguments you just constructed. Here are some topic ideas:

• Floods
• Global warming
• Breast cancer
• Sexism
• Drought
• Slavery
• Imprisonment
• Resource wars
• Inequality
• Forest fires
• Opera
• Imperialism
• Inflation
• Weapons proliferation
• Pineapple on pizza
• Famine

Videos

How to Argue - Philosophical Reasoning:

How to Win an Argument: