ABSTRACT
§ 1 . The evolution of thought has followed a course not unlike that which the ancient philosophers described when they traced the genesis of the world out of chaos. As the ordered world arose out of a previous chaotic condition of matter, so experience began with a chaos of facts, a distinctionless mass of data. From the first, man set himself the task of putting his house in order, and under the direction of immediate interests the mass of known facts was slowly sorted into classes; as the cosmologist would say, it was separated out. The lines upon which we may suppose this progress to have been made were those of specific interests, and the process itself cannot be regarded as undertaken with any idea of acquiring knowledge for its own sake but always in the hope of being able to make life easier and more pleasant. The first categories or heads of classification which man would use would not be the categories of science but of practice. Thought at this stage must have been chiefly employed in preserving all that a man considered worth preserving, primarily his own life and after that the life of those whom he loved or the property toward which he felt an affection not unlike the sentiment of kinship; so that his first categories were those of action, rough classifications of things as harmful or harmless, eatable or poisonous, to be avoided or pursued, to be cherished or destroyed.
