That which is found in the bible.
This is one of the biggest problems with issues like this. Most Humanists seem to think that modern US fundamentalist Protestantism is 'proper Christianity' rather than a minority movement that has only existed for a fraction of the religion's history.
'That which is found in the Bible' reflects only a small proportion of the Christian tradition.
I think the key difference between a "divine morality" and a secular humanist morality, is that in the latter you actually have give a well reasoned argument as to why you think something is moral / immoral.
In "divine morality", you don't. Then the reason is just, at bottom, "because god says so".
Again, this facile stereotype does not reflect the history of Christianity in any meaningful way. Too many Humanist arguments are against a straw-Christianity, and rely on historical myths that are universally rejected by secular scholars as they would know if they bothered to actually read any.
The same place christianity (and all other religions / philosophies) came from: the human mind.
The human mind is profoundly influenced by the cultural environment in which it develops. Humanists tend to see the axioms underpinning their ideology as 'natural', 'universal', yet the evidence is that they are very uncommon and culturally dependent. It wasn't too long ago people were claiming the End of History as they assumed the former, but reality tends to confirm the latter.
Over time, certain cultural assumption become so ingrained in a society that we often think they have always existed and are self-evidently correct, but when we look outside of our bubble we see that they are far from 'natural', and are anything but 'self-evident common sense'.
Don't you wonder why Humanism developed in one specific cultural environment but not in all of the others?
Something I wrote in an
old thread re: modern science, but pretty much applies equally to Humanism too:
In the conclusion to the above lecture, Peter Harrison identifies 2 broad trends in thinking about how religion relates to the development of modern science that may lead to very different perspectives on the issue:
1) What were the unique and contingent conditions that made possible the emergence and persistence of [the modern concept of] science?
2) Given it's inevitability and intrinsically progressive nature, what are the factors that have inhibited or slowed down the development of science and the scientific mind?
The 2nd view, which relies heavily on a teleological view of history and the post-Enlightenment
Idea of Progress (ironically itself an offshoot of Christian theology), is the view usually presented by those who favour the Conflict Thesis. It rests on an assumption that science is something which comes naturally to us and simply requires the absence of constraint in order to emerge. This often aligns with a common perspective that Western Humanistic culture is the universal result of education, reason and progress, and other cultures tend to represent a more 'primitive' phase which has yet to be outgrown. In this case, the removal of obstacles is a core dimension in the development of science, and Christianity, by it's attachment to faith and timeless doctrines, was the key obstacle.
The 1st view considers that science was not the inevitable consequence of progress. Both the Idea of Progress and the development of modern science are seen as being specific products of a particular culture that required a number of necessary variable to be fulfilled. Seeing as these dimensions seem to have been rare in human societies, the key to understanding the development of science is to understand what were the factors which caused such dimensions to be present.
As such it is difficult to find common ground as the different views really represent different perspectives on the human condition.
I'm just saying it was break-away from religious rule.
It wasn't "christianity" that produced this, nore did it push for it. If anything, it was dragged along kicking and screaming - as you yourself acknowledge in the above paragraphes with your use of the word "conflict" and with the wikipedia quotes, which mention the controversy it sparked.
It was 'dragged along kicking and screaming' by theologians carrying out scriptural exegesis and theological argumentation. Disputes within Christianity are by their nature Christian.
That is not to say all Christians accepted them, or that no other cultures had any of them, or that these could not have been reached via another method - as an atheist I don't think there is anything magical about Christianity after all.
The point is that the 'right combination' of beliefs were a) not common across cultures and b) clearly developed, to some extent, via explicitly Christian discourse.
Pretty much of the things that make up ideals of Humanism developed in such a manner. Christianity demonstrably made a major contribution to the development of modern science, the preservation of classical schoalrship (literature and philosophy), the university system, the Idea of Progress, a common Humanity, human rights, equality, individualism, secularism, etc.
Do you agree with any of those? (they are easy enough to support with historical and scholarly literature if you are interested, but don't want to tl;dr you any further)
The point is that I simply disagree that secular humanism is some kind of "logical extension" of christianity. It isn't.
If we look at pre-Christian West (Graeco-Roman, but generally common in most ancient societies), what emerged in the Christian tradition, then Humanism we see a lot of commonalities"
Graeco-Roman, Christian, Humanist
Time: cyclical, progressive, progressive
Teleology: no, yes, yes
Equality: no, yes, yes
Moral unit: family/society, individual, individual
The weak: to be exploited, to be nurtured, to be nurtured
Outlook: Tragic, optimistic (salvation), optimistic (progress)
Scope: 'tribal', universal, universal
Humanism: equality, individual rights, idea of progress, support for modern science, secularism, naturalism.
Things that were significantly impacted by the Christian tradition, perhaps with other influences too: equality, individual rights, idea of progress, modern science, secularism
Far from one being the rejection of the other, if you created a metric to compare all historical belief systems, liberal Christianity and Humanism would be among the most similar.