Board Thread:General Discussion/@comment-32182236-20190721003717/@comment-32182236-20191229133843

As a result, Part 3 is over. Part 4 is next.

The burden of proof and reductio ad absurdum are showing up here. You've seen how to take a few premises and use them to form a new conclusion, thus proving the conclusion true.

But there's actually a way to prove a premise false.

If you can set up an argument with premises we know are true, plus a premise that we're trying to test.. And logically, they lead a conclusion that we KNOW to be false, then the premise we're testing must also be false.

Reductio ad absurdum is quite the powerful argument. (Unfortunately, it and the strawman tend to get mixed up quite a bit.)