Lies as self defence vs. Physical self defence Why is a lie for the purposes of self defence necessarily unwholesome? Why is using a lie as defence for another from attack considered  parajeeka for a monk when a monk can use physical self defence and it's not parajeeka? Why can't a monk misrepresent reality(lie) for self defense instead of resorting to physical violence? 

As long as you know what the truth is why give it to someone who would exploit it?

I was thinking that our intentions aren't unwholesome because we lie but a lie is unwholesome because of our unwholesome intentions. -Metta
The key is intent to deceive and the person understanding the deceptive communication. If the intention to deceive is not there then there is no unwholesome. If you mistakenly believe something and say this it is not breaking the precept of lying because there is no intention to deceive.

Generally, people do not like being deceived, even for their own good. So if you are motivated to deceive for their own good, then this is still lying.

If you make a promise you do not intent to keep this also is lying. If you make a promise which you know will never happen then this is not lying (e.g. I will give you an angle to marry if the sun rises in the North.) The latter type of tact was used on Nanda, in which case the promise was if you meditate.

Also I do not think a monk can resort to violence.

Also need not always tell what you know. You can simply refuse to answer, but if you answer it should be the truth.