"human descriptive language differs from all animal languages in being ... argumentative, and ... it is human argumentative language which makes criticism possible, and with it science.

"There is a world of difference between holding a belief, or expecting something, and using human language to say so. The difference is that only if spoken out, and thus objectivized, does a belief become criticizable. Before it is formulated in language, I may be one with my belief: the belief is part of my acting, part of my behavior. If formulated, it may be criticized and found to be erroneous; in which case I may be able to discard it."

Karl Popper, "Campbell on the Evolutionary Theory of Knowledge." Evolutionary Epistemology, Rationality, and the Sociology of Knowledge. Eds. Radnitzky, G. and Bartley III, W., Open Court, 1987.