'What is the nature of mind?' This question, propounded when man first became conscious of himself, still remains but inadequately answered. Nevertheless, some evident progress has been made. The light of scientific progress is gradually penetrating the various nooks and recesses of our mental life, and the machinery of thought, although dimly revealed, is becoming more apparent in its operation. This monograph is but a mere fragment, explaining little if anything regarding the dynamics of mental process, yet it hopes to place a variety of perplexing problems in a new perspective. We shall have occasion, for example, to examine some current definitions of intelligence, and we shall indicate wherein our research into the value and significance of completion and combination tests forces us to a reconsideration of the criteria of intelligence and to a restatement and a redefining of some fundamental principles.

Includes music.