It’s often said, just dropped in by modern people who take the scientific view, that morals have changed a great deal over their lifetimes, over the world, and over the generations in their own countries. This position, the dominant position, is called “cultural relativism”—with morals being relative in time and space.
What I am about to say is not “absolute morality”, but it is as close to it as you can get. The principles of British law, of European law, remain the threefold rules laid down by the Roman jurist Ulpian in about 260 AD:
1. make an honest living;
2. don’t hurt anybody;
3. render what is due to each man.
Those three principles are meant to provide the basis for all laws—and represent a summation of principles that informed Roman law back to before Christ. So these principles, which haven’t changed for over 1,500 years, date back perhaps as far as 2,500 years.
Obviously, these principles also inform American law, Brazilian law, Russian law (because Ulpian’s code was used by Byzantium and Eastern Orthodoxy), and any country Europeans colonised.
These three principles can apply to a Muslim, a Jew, or a Christian—a black man or a white man. The closer you live in accordance to them, the more you can be said to be a “good” man so far as any man can be said to be good without getting into specific paths of salvation.
Of course, there are metaphysical and practical questions around those principles—the most vexed is “render what is due to each man”, because people have different conceptions as regards “just deserts”, whereas it is easier to see what “don’t hurt anybody” means.
Further, as regards specific moral codes, not those that could apply to any man, the seven virtues are prudence, temperance, fortitude, justice, faith, hope, and charity—the first four date back to Stoicism and beyond Stoicism to Plato.
The seven virtues were the standard moral code in the West for at least the 1,000 years when Christendom existed—and carried on even when Christendom split, even down to today.
The four cardinal virtues—prudence, temperance, fortitude, and justice—go back to Plato, if not beyond, so again we’re back to something like 2,500 years; and, further, we can add the Ten Commandments to Christendom—and those go back to at least 750 BC.
So where is the moral relativism?
Well, perhaps you mean sub-issues, because a concept like “justice” is very broad—and people have different ideas as regards what it means to “give someone his due”. But even if you accept that then the meta-principle “give men their due” has applied for thousands of years, even if men have different ideas as to what it means.
Yet men like Karl Pearson, men who claim that only science provides knowledge, say that there has been great variation in morals over time and within societies and between societies—and that is claimed down to today as “cultural relativism”.
Pearson talked about how morals had changed since his grandfather’s time. Since he was born in the 1850s, that really meant in the 1790s; and that, in turn, meant during the period of the French and American revolutions—the dawn of modern science and the Enlightenment.
So “moral change” and “moral relativism” really started in the last two centuries, when everything was questioned and there was an idea that people had to start from scratch—and when it was thought that, like bodies in Newtonian philosophy, there was relative motion at work.
Since that change only happened in the West, a relative shift in morals occurred elsewhere later—and, further, it should be noted that, for example, the Muslim countries, tied into the Abrahamic tradition, had many points of moral consensus for over a millennium with Western countries.
“The treatment of women…” Muslim and Christian countries treat women differently, but both sought to promote modesty—they only differed in the degree to which and the means they used to pursue modesty, a “moral difference” that while significant is far from a “relative moral standard”, if by that you mean “a different standard”; and the classical world also pursued female modesty—as did very different civilisations, like China.
In substantial terms, there has been long-term agreement about moral conduct—albeit disagreement over the specifics.