THIS volume, written in 1905 as a sequel to the same author's "Mont Saint Michel and Chartres," was privately printed, to the number of one hundred copies, in 1906, and sent to the persons interested, for their assent, correction, or suggestion. The idea of the two books was thus explained at the end of Chapter XXIX: - "Any schoolboy could see that man as a force must be measured by motion from a fixed point. Psychology helped here by suggesting a unit - the point of history when man held the highest idea of himself as a unit in a unified universe. Eight or ten years of study had led Adams to think he might use the century 1150-1250, expressed in Amiens Cathedral and the Works of Thomas Aquinas, as the unit from which he might measure motion down to his own time, without assuming anything as true or untrue, except relation. The movement might be studied at once in philosophy and mechanics. Setting himself to the task, he began a volume which he mentally knew as 'Mont-Saint-Michel and Chartres: a Study of Thirteenth-Century Unity.' From that point he proposed to fix a position for himself, which he could label: 'The Education of Henry Adams: a Study of Twentieth-Century Multiplicity.