Chanakya Neeti 17
Even if a snake is not poisonous it should hiss, that can scare away its enemies.
Another sage suggestion, this world is not meant for harmless persons, those who are should feign that they are not! There is nothing good in harming others, but there is nothing bad in pretending that you do, especially if you are forced to!
Chanakya was the mentor, guide and prime minister of Emperor Chandragupta Maurya. His words were very wise when it came to explaining human nature and ways of actual world.
As I am too engrossed with my twins (agnishatdalezine.wordpress.com and agnijaat.wordpress.com- check them out guys, my twin Ezines Agnishatdal and Agnijaat) I will use him as my own and your teacher for at least a couple of months. Hope you will benefit too!