The interaction of individuals, possessing different knowledge and different views, is what constitutes the life of thought. The growth of reason is a social process based on the existence of such differences. . . . [I]ts results cannot be predicted . . . . [W]e cannot know which views will assist this growth and which will not.

and

Liberty is essential to leave room for the unforeseeable and unpredictable; we want it because we have learned to expect from it the opportunity of realizing many of our aims. . . . [W]e trust the independent and competitive efforts of many to induce the emergence of what we shall want when we see it.