Art, just as morals and pure science, differs entirely from the natural sciences, which are generalizations based upon acquired information and must change as long as the information upon which they are based can be modified and enlarged. But where, as in art or pure science, principles are based on final truths, the principles have also a finality and can only be rejected if their basis can be changed or modified. Aristotle’s principles have something of that finality. Aristotle had for his study a body of literature that has for centuries met with the approval of the best taste in every age and of every critic. Aristotle’s biology or physics are not final, but his ethics, his logic, his esthetics are in measurable distance of finality except where some additions have been made to the materials upon which he based his analysis. In religion, because of revelation, in music because of discoveries in instrumentation, and perhaps in other arts, time has added to the original store, but in literature there are few additions to the fields which lay before Aristotle, and subsequent ages have not developed any keener analytical powers than those of Aristotle. It is Aristotle’s principles that in the main have dominated the writer’s reactions to modern art and literature. When Greek literature held an honored place in our schools, there was less need of insisting on obvious truths of art. The intense modernism now predominating everywhere has driven classical literature and classical methods from school and life. History is modernized too or fails to supply the vital contact with the ever-living past which earlier schools experienced in the poets, historians, orators and philosophers of Greece and Rome. So-called cultural subjects in modern education are chiefly informational. Culture is a word which calls for definition, but on its intellectual side at least, culture for the largest number of persons in the world can be gauged most satisfactorily by their appreciation of literature and by their capacity to produce literature. The study of literature as an art is the chief topic of this book, and Aristotle’s great principles need all the more stressing now that his philosophy of art and the supreme literature on which he based his conclusions are passing away from present-day consciousness. The chapters that follow are popular rather than scientific in presentation. Readers who seek a fuller and wider view may be interested in such a work as Benedetto Croce’s _Æsthetic_, from the Italian by Douglas Ainslie. Its historical summary, especially for modern times, is valuable and good. For the Greeks and earlier periods, Butcher’s _Aristotle’s Theory of Poetry and Fine Arts_ is easily best. Professor Rhys Roberts’ editions of the works of Dionysius, Longinus and Demetrius are excellent for the traditions of classical rhetoric, a tradition weak in America.