What do you mean by non-violence?
"Don't be violent to anyone; don't hurt anyone!"
Being angry with someone is also violence. Even such violence is not advisable. Then only it can be called true non-violence.
"But if someone hurts us, how can we be non-violent?"
That is the test of non-violence in true sense! Then no one will dare hurt us, nor make us angry. Even animals remain non-violent in such case!
"Won't people call us coward if we let others beat us?"
"Why would they call us cowards? We are not afraid of the beating! We don't even run away due to fear and we don't express grief for being hurt! We don't get angry because of love we have for all. Why would we be called coward just because we don't hurt anyone?"
"It is rather difficult not to slap anyone even though one hurts you! Loving such person is difficult too! In fact, slapping the person in return is very easy!"
It's true that being non-violent is not so easy! Only the brave ones can practice non-violence; the cowards cannot do so!
Gandhiji practiced such non-violence and advised us to do so!