“The only thing necessary for the continuance of evil is for a good man to do nothing.”
“The only thing necessary for the triumph of evil is for good men to do nothing.”
“The only thing necessary for evil to conquer is for us and those like us to do nothing.”
“All that is necessary for evil to prevail is for good people to do nothing.”
“Do not let us mistake necessary evils for good.”
“Evil can only prosper when good people stay quite and do nothing about it. Don't let evil prosper!”