Who has no mercy upon inferiors will suffer from the tyranny of superiors.
Not every arm which contains strength
Breaks the hand of the weak for showing bravery.
Injure not the heart of the helpless
For thou wilt succumb to the force of a strong man
Saadi Shirazi
http://www.poemhunter.com/poem/ch-08-on-rules-for-conduct-in-life-maxim-73/
