I'd say they emerged as a result of changing economies and politics, as well. Further, demographic shifts may have played a role. I think technology is a great index of that, although there's an anthropological bias there, in that for past events, we are trained to look at artifacts. For example, it's clear that the earliest cave paintings (preserved) occur in two places: Southern France and just north of the Black Sea. The people appear to be genetically related, certainly through their mtDNA lines. At first, both only have ground charcoal (black) pigment and red ochre (dark orange), but soon another form of ochre is found in Southern France - so the two traditions diverge in that regard. Not long after, both places start grinding various minerals/semi-precious stones to get a few more colors. By "not long" I mean a few thousand years. But the two painting cultures work in parallel and the themes in the art are similar - as the earliest art found in North Africa and in Australia. I think your answer is very sound (and OP, take note that your idea that systems of behavior or belief become "opposite" of what they were is quite controversial). The Renaissance is, to me, primarily an historical periodization and for good explanations of it, I'd ask on /r/askhistorians What is clear is that it likely occurred first in the Lowlands of Europe (The Netherlands and perhaps Belgium), and that arose from earlier trade routes involving artists, other peripatetic occupations, and the high number of well-off customers who used the area as a shopping center for many things. Why medieval artists gradually changed their "view" or their skillset is, to me, inadequately explained, but certainly the rise of artists' workshops played a big role, as talented young apprentices could be imported (and exported). For whatever reason (perhaps due to the influence of bankers), this style of art and architecture caught on in Italy. Trying to explain someone like Leonardo, though, is a hard reach for any scientific or objective discipline. By the third generation of artists after the High Renaissance, there was a decline in spending (especially by nobility and the churches), which decreased the number of apprentices and artists. The very techniques known to previous generations were not exactly lost, but certainly not taught and learned in exactly the same way. I don't think this change in art can be shown to have anything to do with other Enlightenment changes in culture (or technology), but it's tempting to think it's all interconnected. The recovery of Greek and Latin manuscripts at the beginning of the Renaissance and renewed energy in teaching young men (mostly) to read in those languages is surely important in the rise of the Enlightenment. Enlightenment knowledge and ideals was never thoroughly disseminated through the rank and file of European cultures, nor is it thoroughly disseminated today. A really good read on how societies transform through "sickness" was written by Robert Edgerton: *Sick Societies: Challenging the Myth of Primitive Harmony*. Most of his case examples show a decided absence of Enlightenment principles and ideals in those societies. I've read most of his primary sources, which not only support what he says, but definitely gave me a different view on culture change. The chapter on Appalachia will stay with you, if you ever read it. At any rate, he really challenges the notion that inherent problems in a society will somehow cause it to change. Nearly all of the case studies in his book show people living outside the Enlightenment (or the Renaissance). Naturally, not every person living during those periods was affected by those movements - not at all. Paul Johnson's *Intellectuals: From Marx and Tolstoy to Sartre and Chomsky* shows how individual minds get made up or change, by using the most influential thinkers/writers of the time. And, of course, the three greats (Marx, Weber and Durkheim) all have strong views on how this kind of change occurs, and reading their primary sources is definitely worthwhile. I would add Engels, too (his *Origin of Family, Private Property and the State* is dated now, but not easily replaced by some other person's writings. Ideas occur in the minds of human individuals, but surely we transmit them in various ways. Individual-focus (as in the work of Coles and Coles) is therefore quite interesting to study.