upon observation of the activities of natural objects, and ideas about such affairs had to be checked, to some extent, by results. But even in such things there was an undue reliance upon mere custom, followed blindly rather than understandingly. And this observational-experimental method was restricted to these 'practical' matters, and a sharp distinction maintained between practice and theoretical knowledge or truth. (See Ch. XX.) The rise of free cities, the development of travel, exploration, and commerce, the evolution of new methods of producing commodities and doing business, threw men definitely upon their own resources. The reformers of science like Galileo, Descartes, and their successors, carried analogous methods into ascertaining the facts about nature. An interest in discovery took the place of an interest in systematizing and 'proving' received beliefs.
A just philosophic interpretation of these movements would, indeed, have emphasized the rights and responsibilities of the individual in gaining knowledge and personally testing beliefs, no matter by what authorities they were vouched for. But it would not have isolated the individual from the world, and consequently isolated individuals—in theory—from one another. It would have perceived that such disconnection, such rupture of continuity, denied in advance the possibility of success in their endeavors. As matter of fact every individual has grown up, and always must grow up, in a social medium. His responses grow intelligent, or gain meaning, simply because he lives and acts in a medium of accepted meanings and values. (See ante, p. 36.) Through social intercourse, through sharing in the activities embodying beliefs, he gradually acquires a mind of his own. The conception of mind as a purely isolated possession of the self is at the very antipodes of the truth. The self achieves mind in the degree in which knowledge of things is incarnate in the life about him; the self is not a separate mind building up knowledge anew on its own account.
