system
Given the following post, respond as if you're commenting on Reddit:
human
What are good questions for detecting logical fallacies?

What are some good questions to ask someone (or yourself) when they make a claim, in order to quickly evaluate (without needing to do independent research) the likelihood that their reasoning is sound? I understand that the best way to evaluate a claim involves some research, but I'm looking for quick rules of thumb here that can be used with someone in real time.

Ideally each question would uncover many logical fallacies, and not just be a check for a single fallacy. Bonus points if they are non-confrontational. 

Here's what I have so far, in no particular order:

1. **What would convince you otherwise?**   
If nothing that could be reasonably expected would change their mind, then it's not evidence-based.
2. **Does the same logic make sense when applied to the other side?**  
example: If the other's desire for more laws implies they are totalitarian, does your desire to repeal laws imply you are an anarchist?
3. **What are the good arguments of the other side?**  
If they make the other side seem stupid/evil, they are probably acting in bad faith and/or didn't research what the opposing scholars say.
4. **How do you know that?**  
It's a good sign if they cite sources.

What are some other good questions for detecting unsound reasoning? Are there any problems with the ones I presented?
gpt
To me, the word "sound" has a precise definition in the context of philosophy. For an argument to be sound is for  it to be "valid" and for it's premises to be true. An argument is valid if there is no way that both the conclusion is false and the premises are true. To determine the soundness of an argument, first you determine its validity, then you evaluate whether the premises are true.

Testing for validity is simple, you assume the premises are all true, then try to conceive of a scenario where the conclusion is false. If there is no conceivable scenario where the conclusion is false and the premises true, then you have a valid argument. You can also do this by breaking it down into formal logic statements like "If A then B" and all that and see if it works out, but that's a bit of a drag and not particularly practical during a conversation. Note that validity is a relatively weak distinction. For example, if the premises are all impossible, the argument is inherently valid. The distinction of soundness avoids these cases by enforcing that all the premises be true.

So with this definition, to argue over soundness is to either contest that the premises being true does not imply the conclusion, or that the premises are not all true in the first place.

I think this definition of soundness avoids you having to think too much about their motivations/bias and all that because even if they are arguing in bad faith or they won't change their mind regardless, if their argument is sound then the conclusion is true whether they know it or not.