On a recent invention of the whole concept of "progress":
The idea that humans should and could work consciously to make the world a better place for themselves and for generations to come is by and large one that emerged in the two centuries between Christopher Columbus and Isaac Newton. Of course, just believing that progress could be brought about is not enough—one must bring it about. The modern world began when people resolved to do so.
On a departure from the beliefs:
The respect for classical texts started to fade away in Europe in the 16th century and went into a meltdown in the 17th, when more and more of the ancient certainties were questioned and then found to be incorrect. If the classic authorities could be wrong about so many things, why would should they be trusted about anything?
On a rise of skepticism:
Worse was to come: After 1600, Europeans developed scientific instruments that allowed them to see things the ancient writers could never have imagined. No wonder they began to feel superior: Ptolemy had no telescope, Pliny had no microscope, Archimedes had no barometer. The great classical writers may have been smart and well-educated, but European intellectuals thought of themselves as equally intelligent and better informed—and thus able to see things the ancients could not. Hence, everything must be tested with real evidence, not on the say-so of authorities who had lived 1,500 years earlier. The motto of the Royal Society, which was founded in 1660 in London, was in nullius verba — “on no one’s word.” Skepticism was the taproot of all knowledge. Even the Bible itself began to be examined critically, not least by Baruch Spinoza, who cast doubt on its divine origins and saw it as just another text.
And finally on progress itself:
Progress, as was realized early on, inevitably entails risks and costs. But the alternative, then as now, is always worse.