Pittacus of Mytilene

"Do not to your neighbor what you would take ill from him."

"Forgiveness is better than revenge."

"Whatever you do, do it well."

"Even the Gods cannot strive against necessity."

"Power shows the man."

"Do not say before hand what you are going to do; for if you fail, you will be laughed at."

"Do not reproach a man with his misfortunes, fearing lest Nemesis may overtake you."

"Speak no ill of a friend, nor even of an enemy."

"Cultivate truth, good faith, experience, cleverness, sociability, and industry."

"καιρὸν γνῶθι"

"Whatever you rebuke your neighbor for, do not do it yourself."