Explain why westerners used the term “progress” to describe the world at the end of the nineteenth and beginning of the twentieth centuries. What did they believe were the sources of this progress?

At the end of the nineteenth century, Westerners believe that something occurred called the "Great Divide," which is when the West achieved modernity and the rest of the world was left behind. This is a Eurocentric argument that assumes that modernity looks a specific way, and for Europeans, that way began with the Scientific Revolution. More than any other period in time, like the Renaissance and Protestant Reformation before that, Westerners believe that with scientific and technological progress of the Scientific Revolution, they moved into modernity, something that only they were capable of having. This then encouraged them to try to spread their version of modernity (westernization) to the rest of the world, which helps explain the imperialism on the late nineteenth and twentieth centuries.
The term "progress," then, was what Westerners used to describe what it takes to be modern. Historian of science Bruno Latour argues that "with the rise of science, we moderns believe, the world changed irrevocably, separating us forever from our primitive, pre-modern ancestors." Progress is what separated the West from the rest, giving support and justification for Western greatness and imperialism throughout the rest of the nineteenth and twentieth centuries. The source of Western progress was medicines (like quinine, extracted from cinchona bark, to prevent malaria while exploring Africa), vaccinations (thanks to microbiologists like Edward Jenner who helped create the vaccine for smallpox), industry (thanks to the Industrial Revolution and European access to coal, which spurred new inventions like the steam train), and science; these were available in Europe and the West, and became the symbols of progress and modernity. Eurocentrism took hold and created that Great Divide, the separation between the West and the Rest over the sake of progress and modernity.
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