"The critics of progress should therefore be met partway. Progress is possible, but not inevitable. Reason can be mobilized to promote social well-being, but can also be overtaken by destructive passions. Human institutions, indeed, should be designed in the light of reason precisely to control or harness the irrational side of human behavior. In this sense, the Enlightenment commitment to reason is not a denial of the unreasonable side of human nature, but rather a belief that despite human irrationality and passions, human reason can still be harnessed - through science, nonviolent action, and historical reflection - to solve basic problems of social organization and to improve human welfare."
(Jeffrey Sachs, "The end of poverty, economic possibilities for our time", chapter "Our generation's challenge").