On Liberty by John Stuart Mill Chapter 2 Page 89

truth should have one-sided asserters too; such being usually the most energetic, and the most likely to compel reluctant attention to the fragment of wisdom which they proclaim as if it were the whole.

Thus, in the eighteenth century, when nearly all the instructed, and all those of the uninstructed who were led by them, were lost in admiration of what is called civilization, and of the marvels of modern science, literature, and philosophy, and while greatly overrating the amount of unlikeness between the men of modern and those of ancient times, indulged the belief that the whole of the difference was in their own favor; with what a salutary shock did the paradoxes of Rousseau explode like bombshells in the midst, dislocating the compact mass of one-sided opinion, and forcing its elements to recombine in a better form