spite of much admirable detailed work, added little of value and much confusion to the theory of vision left us by a great Englishman,—namely, Thomas Young; and in a long series of papers I endeavoured to restate and supplement Young’s theory. Advancing into the field of physiological psychology, I attacked the ponderous volumes of Wundt with enthusiasm; only to find that his physiology of the nervous system was a tissue of unacceptable hypotheses and that he failed to connect it in any profitable manner with his questionable psychology. And, finding even less satisfaction in such works as Ziehen’s _Physiologische Psychologie_, with its crude materialism and associationism, or in the dogmatic speculations of Verworn, I published my own small attempt to bring psychology into fruitful relations with the physiology of the nervous system. This brought me up against the great problem of the relations between mind and body; and, having found that, in this sphere, German ‘idealism’ was pragmatically indistinguishable from thorough-going materialism, and that those Germans who claimed to reconcile the two did not really rise much above the level of Ernst Haeckel’s wild flounderings, I published my _History and Defense of Animism_. And in this field, though I found much to admire in the writings of Lotze, I derived most encouragement and stimulus from Prof. Bergson. In working at the foundations of human nature, I found little help in German psychology, and more in French books, especially in those of Prof. Ribot. In psycho-pathology I seemed to find that the claims of the German and Austrian schools were far outweighed by those of the French writers, especially of Prof. Janet. So now, in attacking the problems of the mental life of societies, I have found little help from German psychology or sociology, from the elaborations of Wundt’s _Völkerpsychologie_ or the ponderosities of Schäffle, and still less from the ‘idealist’ philosophy of politics. In this field also it is French authors from whom I have learnt most and with whom I find myself most in sympathy, especially MM. Fouillée, Boutmy, Tarde, and Demolins; though I would not be thought to hold in low esteem the works of many English and American authors, notably those of Buckle, Bagehot, Maine, Lecky, Lowell, and of many others, to some of which I have made reference in the chapters of this book.