Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 2
An inner psychic or spiritual change is not brought about by violence. It is not a change of conduct that has to be done in the 
sadhak, but a change of soul and spirit governing the mind and vital and body instead of the mind and vital governing. Violence is the drastic contradiction of that; it makes mental egoism and vital passion and fury or else cruelty the rulers. Violence in ordinary Nature does not justify violence in a spiritual work.