Antisthenes used to say that envious people were devoured by their own disposition, just as iron is by rust.
Diogenes LaertiusThere is a written and an unwritten law. The one by which we regulate our constitutions in our cities is the written law; that which arises from customs is the unwritten law.
Diogenes LaertiusOne of the sayings of Diogenes was that most men were within a finger's breadth of being mad; for if a man walked with his middle finger pointing out, folks would think him mad, but not so if it were his forefinger.
Diogenes Laertius