"What I mean is I assume by "secular community" you mean, secular people in a largely Christian defined West as opposed to say Aztecs or people in Afghanistan, ..."
No. I was including secular in a western Christian dominated world, as well as the religious and secular in Buddhist dominated regions, secular and religious in Muslim dominated regions, ...even the Aztecs :D
"...and my point is that what a society believes is significant to the perceived morality of its people. We are not just automatically moral because some people have empathy in varying degrees."
Well, we may disagree. Morality is different from what is defined as "moral actions." However, even if you distill "moral actions" down far enough, you will find (IMHO) that they all come to the same definition (altruism.) Basically, do no harm to another human or society.
Ritual cannibals in Papua New Guinea did not see their actions as immoral because they felt the person involved was going to paradise, and it was helping the community as a whole. The individual being sacrificed was overjoyed to be sacrificed.
While we, without understanding of the world, would see ritual sacrifice as immoral, this is because we recognize it to be against altruism (it is simply doing harm to the individual.) The tribes in New Guinea saw it as moral, because ti was filled with altruism (good for the sacrificed, good for the community.)
It all still came down to inherent altruism.
"The fact that altruism or empathy exists to some extent at an individual level is beside the point, any moral idea must reflect something within us or else we would not recognise it."
I may simply disagree with this.
"As for the bible and the "last 1800 years", you can argue that between transmission and writing the bible is muddled, or between early now lost texts and extant manuscripts, but in the period since we have a pretty consistent text, scribal errors and interpolations are mostly minor and as far as ancient documents the textual witness to much of the bible as we now have it is remarkably stable."
Mmmm. Maybe, I guess it's a discussion of "recently." For example the word homosexuality only began appearing in the English versions of the New Testament around the 1950's.
And, of course, a completely accurate copy of a wholly inaccurate Bible is still wholly inaccurate. Most of the English translations stem from the King James Bible, which stems from a translation of the Erasmus Greek Bible, which came from a sparse handful of very limited documents, and a retranslation of the Latin Vulgate - which itself was one of hundreds of variations.
https://www.gentles.info/BibleHistory/Index_History.html
And, the text versus the interpretation by reader is neverendingly changing. Even in the modern generation, "What the Bible says" (meaning how the reader interprets the text) is constantly being updated.
Lastly, we musn't forget, that a lot of the "moral actions" (moral directives) found in the Bible stem from the moral directives of the Greeks - which during this time of dramatic alteration to the Bible were being added by translators and transcribers.
"That isn't even a Christian point, you're just making a point no scholar would make. You can look today at the Codex Sinaiticus, for example."
I wholly disagree. In fact there's an entire field of Christianity still actively dedicated to it. You can read one book about it here:
https://www.amazon.de/dp/B000SEGJF8/ref=sr_1_1?linkCode=gs2&tag=interior065-21
Also, none of this has anything to do with the observable fact that morality, and discussions of morality, existed for millennia before the Bible (or Jesus) did.
To claim morality stems from Christendom is simply kind of obviously not the case---because we can spend a lifetime reading books on morality from millennia ago.
