If you take a quick look at our history as humans, most people who went through ascetic life and omniscient men who walked on this earth (like Buddha, The guy who founded Jainism, and great philosophers) all state 'Violence is not the answer'. But this is not practical and is just a norm developed by all religions so that peace sustains among people. In a deeper look, violence means to provoke a conflict. I don't understand under what circumstances a rational person would commit to violence. But when there is injustice and inequality in the system and when the affected people are not given a voice to speak, then violence will be the last source even for a rational thinker. The birth of communism.