How do you know when you have lost the argument?

1.  When the information you relied on is provably false eg you think the earth is flat circled by the sun rather than round and circling the sun.

2.  When your logic is not only unsound, it is invalid eg when you make category errors such as confusing what is unpopular with what is impossible.

3. When you what you propose to do is immoral even if it is logical eg when you rob someone and then kill him to stop him from reporting you to the police.