In recent centuries the novel idea has entered the thought of many religious people that natural law is a Western pagan invention, unsupported by Scripture or by Christian tradition. To illustrate how far this notion falsifies history, I offer the following remark about Scripture from an unimpeachable traditional authority, one of the greatest Eastern Fathers of the Church, John Chrysostom, contained in his Homily 12, section 9. The translation is in the public domain.
“When God formed man, he implanted within him from the beginning a natural law. And what then was this natural law? He gave utterance to conscience within us; and made the knowledge of good things, and of those which are the contrary, to be self taught. For we have no need to learn that fornication is an evil thing, and that chastity is a good thing, but we know this from the first. And that you may learn that we know this from the first, the Lawgiver, when He afterwards gave laws, and said, ‘Thou shalt not kill,’ did not add, ‘since murder is an evil thing,’ but simply said, ‘Thou shall not kill;’ for He merely prohibited the sin, without teaching. How was it then when He said, ‘Thou shalt not kill,’ that He did not add, ‘because murder is a wicked thing’? The reason was, that conscience had taught this beforehand; and He speaks thus, as to those who know and understand the point. Wherefore when He speaks to us of another commandment, not known to us by the dictate of consciences He not only prohibits, but adds the reason. When, for instance, He gave commandment respecting the Sabbath; ‘On the seventh day thou shalt do no work;’ He subjoined also the reason for this cessation. What was this? Because ‘on the seventh day God rested from all His works which He had begun to make.’ And again; ‘Because thou wert a servant in the land of Egypt.’ For what purpose then I ask did He add a reason respecting the Sabbath, but did no such thing in regard to murder? Because this commandment was not one of the leading ones. It was not one of those which were accurately defined of our conscience, but a kind of partial and temporary one; and for this reason it was abolished afterwards. But those which are necessary and uphold our life, are the following; ‘Thou shalt not kill; Thou shalt not commit adultery; Thou shalt not steal.’ On this account then He adds no reason in this case, nor enters into any instruction on the matter, but is content with the bare prohibition.”