Adding and subtracting....................

Create all the happiness you are able to create: remove all the misery you are able to remove. Every day will allow you to add something to the pleasure of others, or to diminish something of their pains. And for every grain of enjoyment you sow in the bosom of another, you shall find a harvest in your own bosom; while every sorrow which you pluck out from the thoughts and feelings of a fellow creature shall be replaced by beautiful peace and joy in the sanctuary of your soul.

-Jeremy Bentham