Put as simply as I can, prior to the 17th century, there was no scientific knowledge to speak of. [I mean that prior to the 17th century books like the following could not be written:
John William Draper, History of the Conflict between Religion and Science, 1875.
Andrew Dickson White, A History of the Warfare of Science with Theology, 1897.]
There was, of course mathematical and some astronomical science, some technical knowledge, common sense, the principle of contradiction, and lots of religion and superstition. With the scientific discoveries, there occured a challenge to religion and superstitions. Those who embraced logic and science became “enlightened.” Those who resisted logic and science remained “unenlightened.” Enlightenment — as I see it — implies secularism (irreligion or non-religion). [There is an organization called “Brights.” It could just as well also be called “Enlightened.”]
So, who are the unenlightened? For starters, all those who embrace a religion. So, using the results of the 2015 PEW poll, 84% of the world is probably unenlightened, and there probably are some in the remaining 16% who are unaffiliated with any religion, who are also unenlightened for embracing some other form of superstition.
Talking about enlightenment, here is an enlightening poll: 1 In 4 Americans Thinks The Sun Goes Around The Earth, Survey Says