At what point must you fight violence with violence?

When drunk

In defense of a woman or child, or sometimes in defense of self.

I work out, I am pretty strong, but what is strength if your mind is still weak?

Sometimes violence is conformity. Sometimes strength is walking away.

Otherwise the cycle continues.

When peaceful resolution is made impossible, or when violence is used against the person or persons.

when violence is the only discernable way to stop the original violence

"Must?" Never.

Rationally? When you've exhausted other options, or when your life or the life of others is in imminent danger.

Peace.

Self defence.

when the safety of yourself and those around you is threatened

I use it when i see no other recourse!

first attack.