ὃ σὺ μισεῖς ἑτέρῳ μὴ ποιήσεις → don't do to others what you don't want them to do to you
P. and V. εὐθύμως (Xen.), P. ἱλαρῶς (Xen.).
affably: P. and V. φιλοφρόνως (Plato), P. φιλανθρώπως.
