The question of what it is morally lawful to do on behalf of a good cause is a very difficult and searching one.  It is perhaps the ‘last infirmity of noble minds’ to think we may do ill that good may come.  I do not think that we ever may, for who knows when the canker of evil, which seemed to us so small, may rot the good?  Who knows what evil followers may creep in because of the evil, not because of the good?  Who knows how much evil in other will be provoked by the evil we do to them?  It is difficult enough in all conscience, to refrain from evil when you honestly try to do so; it is hopeless when you begin to say ‘Some evil is lawful for me, because my aims are good.’  We must always be guided by Kant’s principle of ‘Law Universal.’

– Helena Swanwick, suffragist and pacifist, from her memoir I Have Been Young (1935)