Progressivism is a broad philosophy based on the Idea of Progress, which asserts that advancement in science, technology, economic development, and social organization are vital to improve the human condition. Progressivism became highly significant during the Age of Enlightenment in Europe, out of the belief that Europe was demonstrating that societies could progress in civility from barbaric conditions to civilization through strengthening the basis of empirical knowledge as the foundation of society. Figures of the Enlightenment believed that progress had universal application to all societies and that these ideas would spread across the world from Europe. Sociologist Robert Nisbet defines five "crucial premises" of the Idea of Progress as being: value of the past; nobility of Western civilization; worth of economic/technological growth; reason over faith (scientific/scholarly knowledge obtained through reason and learning must supersede faith); the intrinsic importance and worth of life on Earth. Beyond this, the meanings of progressivism have varied over time and from different perspectives.

Progressivism in the United States is a broadly based reform movement that reached its height early in the 20th century and is generally considered to be middle class and reformist in nature. It arose as a response to the vast changes brought by modernization, such as the growth of large corporations and railroads, and fears of corruption in American politics. In the 21st century, progressives continue to embrace concepts such as environmentalism and social justice. Social progressivism, the view that governmental practices ought to be adjusted as society evolves, forms the ideological basis for many American progressives.