Arthur Holly Compton was one of the great leaders in physics of the twentieth century. In this volume, Robert S. Shankland, who was once a student of Compton's, has collected and edited the most important of Professor Compton's papers on X-rays—the field of his greatest achievement—and on other related topics. Compton entered the field of X-ray research in 1913 and carried on active work until the 1930s, when he began to specialize in cosmic rays.

During the years when Compton was an active leader in X-ray research, he made many notable contributions which are reflected in the papers presented here. He was the first to prove several important optical properties of X-rays, including scattering, complete polarization, and total reflection. He was also the first, with his student R. L. Doan, to use ruled gratings for the production of X-ray spectra.

Professor Compton's greatest discovery, for which he was awarded a Nobel Prize in 1927, was the Compton Effect. This was the outgrowth of experiments he had initiated during a year at Cambridge in 1919-20. He did the major portion of these experiments at Washington University in St. Louis during the period 1920-24. His work demonstrated that in the scattering of X-rays by electrons, the radiation behaves like corpuscles, and that the interaction between the X-ray corpuscles and the electrons in the scatter is completely described by the principles of the conservation of energy and momentum for the collisions of particles.

In his introduction, Professor Shankland gives a historical account of the papers, narrates Professor Compton's early scientific career, and shows how he arrived at a quantum explanation of the Compton scattering after eliminating all classical explanations.

"All political action has . . . in itself a directedness towards knowledge of the good: of the good life, or of the good society. For the good society is the complete political good. If this directedness becomes explicit, if men make it their explicit goal to acquire knowledge of the good life and of the good society, political philosophy emerges. . . . The theme of political philosophy is mankind's great objectives, freedom and government or empire—objectives which are capable of lifting all men beyond their poor selves. Political philosophy is that branch of philosophy which is closest to political life, to non-philosophic life, to human life."—From "What Is Political Philosophy?"

What Is Political Philosophy?—a collection of ten essays and lectures and sixteen book reviews written between 1943 and 1957—contains some of Leo Strauss's most famous writings and some of his most explicit statements of the themes that made him famous. The title essay records Strauss's sole extended articulation of the meaning of political philosophy itself. Other essays discuss the relation of political philosophy to history, give an account of the political philosophy of the non-Christian Middle Ages and of classic European modernity, and present his theory of esoteric writing.

What Is Taoism? traces, in nontechnical language, the history of the development of this often baffling doctrine. Creel shows that there has not been one "Taoism," but at least three, in some respects incompatible and often antagonistic. In eight closely related papers, Creel explicates the widely used concepts he originally introduced of "contemplative Taoism," "purposive Taoism," and "Hsien Taoism." He also discusses Shen Pu-hai, a political philosopher of the fourth century B.C.; the curious interplay between Confucianism, Taoism, and "Legalism" in the second century B.C.; and the role of the horse in Chinese history.