Aristotle Nicomachean Ethics 4.8
To the middle state belongs also tact; it is the mark of a tactful man to say and listen to such things as befit a good and well-bred man; for there are some things that it befits such a man to say and to hear by way of jest, and the well-bred man's jesting differs from that of a vulgar man, and the joking of an educated man from that of an uneducated. One may see this even from the old and the new comedies; to the authors of the former indecency of language was amusing, to those of the latter innuendo is more so; and these differ in no small degree in respect of propriety. Now should we define the man who jokes well by his saying what is not unbecoming to a well-bred man, or by his not giving pain, or even giving delight, to the hearer? Or is the latter definition, at any rate, itself indefinite, since different things are hateful or pleasant to different people? The kind of jokes he will listen to will be the same; for the kind he can put up with are also the kind he seems to make. There are, then, jokes he will not make; for the jest is a sort of abuse, and there are things that lawgivers forbid us to abuse; and they should, perhaps, have forbidden us even to make a jest of such. The refined and well-bred man, therefore, will be as we have described, being as it were a law to himself.
Romans 2:14
13 For it is not those who hear the law who are righteous before God, but those who do the law will be declared righteous. 14 For whenever the Gentiles, who do not have the law, do by nature the things required by the law, these who do not have the law are a law to themselves. 15 They show that the work of the law is written in their hearts, as their conscience bears witness and their conflicting thoughts accuse or else defend them,
Notes and References
"... The three apparent echoes of Aristotle in Romans 2:14–15 are the phrases, they are a law to themselves, the work of the law, and accuse or even excuse. None of these Greek expressions has an analogue in the LXX ... In the course of his Nicomachean Ethics, Aristotle discusses the witty man, in contrast to the buffoon; he commends the way that a free man (i.e., a gentleman or civilized man) carries out his jesting. The lawgivers have forbidden certain forms of verbal abuse, and probably some forms of joking should be forbidden as well. In IV.viii.10 (1128a, 31–32) Aristotle sums it up ... The point is that such a person needs no imposed law to make him behave the right way; he has some kind of internal monitor that guides him. This is the force of the expression, being a law to himself ..."
Collins, C. John Echoes of Aristotle in Romans 2:14-15: Or, Maybe Abimelech Was Not So Bad After All (pp. 123-173) Journal of Markets and Morality, Vol. 13, No. 1, 2010