The highest endowment of the human spirit on the intellectual side is the power to think. Learning to think is an essential process and end in all school work. Thinking is the intellect's regal activity. In a vague way, all teaching appeals to the thought-activity of the pupil. The power to analyze and synthetize thought-complexes is the most fruitful endowment of the intellectual life. Expression without adequate reflection is productive of superficiality. The author has brought to this book the matured convictions of broad training in American and European systems of schools, and a wide and successful experience in teaching pupils and directing systems of education.