Yesterday while being domestic, I was listening to podcasts. The following one was so cool, I actually decided to transcribe it for you because it was both concise and chock full of good information.
Here is a pretty close transcript to this podcast episode. It's not exact, so you can listen to it to get everything I left out, which was where someone started a sentence or a thought and didn't finish it, stuff like that. I also turned it into more of an article and less of a conversation. So really, it's a companion to listening to the podcast (which is about 6 minutes) and for your convenience.
How To Structure A Logical Argument
by the Skeptics' Guide 5x5, Episode 62, March 19, 2009
There are two components to any argument:
- Premises - the facts you base your argument on
- Logic - connects your premises to the conclusion that you're trying to draw
Some important properties of logical systems should include:
- Consistency: nothing in your argument should contradict one another.
- Soundness: the system rules for proof will never allow false interference from a true premise
- Completeness: there are no true sentences in the system that cannot be proved in the system
It's very important that logical arguments are only about factual claims and not value judgments. Value judgments are by definition subjective and are not amenable to logical arguments.
Another important thing to keep in mind is what logical fallacies are and to look for them not just in your opponent's argument in order to deconstruct that, but also to get them out of your own argument. It's very easy to fall into certain traps without realizing it. Studying common logical fallacies can really help you tone up your own logical argument.
One key is that the purpose of an argument shouldn't be to win. It should be to figure out what is valid, what is true. If two people disagree, then one or both people is making an unsound argument. So something would be wrong with one or both arguments.
- Unsound argument: not based both on true premises and valid logic.
First Goal: Decide what the common ground is. What are the points you can both agree upon? What are the premises that are rock solid? Then proceed very carefully from there, examining each premise and all of the logic every step of the way to find out who is wrong here, who is making the incorrect assumption, who is making a hidden premise, who is committing a logical fallacy or are both of you?
Don't neglect your own arguments. Don't assume you're right and the other person is wrong. Proceed in a careful manner.
If two people examining the same math problem came to a different answer they wouldn't just start yelling at each other. They'd say OK, let's go through it step by step and see who made a mistake, or maybe both of us made a mistake and we'll figure out what the right answer is.
An argument is the same thing. It has a structure.
One important thing to note: if you start with premises that are true, and you make a valid logic, that is what is called a Sound Argument. The conclusion of a sound argument must be true, by definition. Therefore if two people disagree they can't both be making sound arguments. And that includes yourself.
Also, you really do need to listen to the person you're arguing with. A large portion of the discussion is going to be reacting to the other person. You're going to be formulating your thoughts, ideas and responses as that person is telling you what they believe. You're preparing your next statement as you go. You really do need to take into account what they're saying, or else you're having a one sided discussion.
A good component of a constructive argument: It's very helpful to try to explain your position to someone else. When you are forced to make someone else understand your position, then it really exposes some of the holes and gaps in your logic and your thinking. You're trying to make your position unambiguously understood. You're exposing all of your premises, you're not hiding them. You're exposing all of your logic, you're explaining it to yourself and the other person at the same time, and then you're giving them the opportunity to do the same thing.
Again, a good place to start is, what is the common ground. What are the things we can agree upon?
Some discussions are about value judgments, and if you expose that, OK we're talking about something that is a subjective opinion here, then you can at least agree to disagree and then you're not wasting your time that can't be resolved with facts and logic.