"Once you have done a man a service, what more would you have? Is it not enough to have obeyed the laws of your own nature, without expecting to be paid for it? That is like the eye demanding a reward for seeing, or the feet for walking. It is for that very purpose that they exist; and they have their due in doing what they were created to do. Similarly; man is born for deeds of kindness; and when he has done a kindly action, or otherwise served the common welfare, he has done what he was made for, and has received his quittance.” – Marcus Aurelius