The following pages are the answer to questions which a young man asked himself when, fresh from the university, he found himself adrift in the great galleries of Europe. As he stood helpless and confused in the presence of the visible expressions of the spirit of man in so many ages and so many lands, one question recurred insistently: Why are these pictures? What is the meaning of all this striving after expression? What was the aim of these men who have left their record here? What was their moving impulse? Why, why does the human spirit seek to manifest itself in forms which we call beautiful?