Want to win every argument? The catch is it's not necessarily on your terms.

The only true way to change someone's mind is with a truth (to them)
bigger then the truth being contested.

Armchair Critics

It's easy to give criticism, much harder to give solutions that actually work.

How to protect yourself from mental attacks.

The hostility towards someone else stems from fear. Defending yourself won't work,  making them feel better may not and definitely won't in the long term. It's an individual security issue and they are trying to control the situation and make that fear go away.  Learn to be brave,  and learn to spot someone who isn't.  When you learn to do that, you will not take attacks as personal and prevent unconscious attacks on others.

Controlling Mind Games

Normal people doing their best and making normal mistakes.
It's said that modern education and learning techniques discourage and punish mistakes,  so we instinctively avid things that we might get wrong... 

Ever had that person in your life that is always on your back or criticising you? No matter how much you do right,  they'll make a big deal about that one tiny mistake.

Is there a chance they don't want us to get it right? They aren't over critical,  they are looking for your flaws and failures,  they could be deliberately setting you up for failure...  We all want to be praised and accepted so often we work harder to please the person who cannot be pleased. Maybe we should ask ourselves what these people's motives are...  And if it's not about the spirit of or the ethic of,  then chances are its not the mistakes that are the problem...  To them, you are the problem!

They are the one with the problem,  not you. Its their problem, not yours and don't let it be, don't let yourself play their games...  Stop trying to get it right for them,  because in their eyes you probably never will.