Among historians of the Southwest the general rule has been to be careful with facts and equally careful in avoiding thought-provoking interpretations. In the multitudinous studies on Spanish-American history all padres are "good" and all conquistadores are "intrepid," and that is about as far as interpretation goes. The one state book of the Southwest that does not chloroform ideas is Erna Fergusson's _New Mexico: A Pageant of Three Peoples_ (Knopf, New York, 1952). Essayical in form, it treats only of the consequential. It evaluates from the point of view of good taste, good sense, and an urbane comprehension of democracy. The subject is provincial, but the historian transcends all provincialism. Her sympathy does not stifle conclusions unusable in church or chamber of commerce propaganda. In brief, a cultivated mind can take pleasure in this interpretation of New Mexico--and that marks it as a solitary among the histories of neighboring states. The outstanding historical interpreter of the Southwest is Walter Prescott Webb, of the University of Texas. _The Great Plains_ utilizes chronology to explain the presence of man on the plains; it is primarily a study in cause and effect, of water and drought, of adaptations and lack of adaptations, of the land's growth into human imagination as well as economic institutions. Webb uses facts to get at meanings. He fulfils Emerson's definition of Scholar: "Man Thinking." In _Divided We Stand_ he goes into machinery, the feudalism of corporation-dominated economy, the economic supremacy of the North over the South and the West. In _The Great Frontier_ (Houghton Mifilin, Boston, 1952) he considers the Western Hemisphere as a frontier for Europe--a frontier that brought about the rise of democracy and capitalism and that, now vanished as a frontier, foreshadows the vanishment of democracy and capitalism. In _Virgin Land: The American West as Symbol and a Myth_ (Harvard University Press, Cambridge, Massachusetts, 1950) Henry Nash Smith plows deep. But the tools of this humanistic historian are of delicate finish rather than of horsepower. To him, thinking is a joyful process and lucidity out of complexity is natural. He compasses Parrington's _Main Currents in American Thought_ and Beadle's Dime Novels along with agriculture and manufacturing. Excepting the powerful books by Walter Prescott Webb, not since Frederick Jackson Turner, in 1893, presented his famous thesis on "The Significance of the Frontier in American History" has such a revealing evaluation of frontier movements appeared As a matter of fact, Henry Nash Smith leaves Turner's ideas on the dependence of democracy upon farmers without more than one leg to stand upon. Not being a King Canute, he does not take sides for or against social evolution. With the clearest eyes imaginable, he looks into it. Turner's _The Frontier in American History_ (1920) has been a fertile begetter of interpretations of history.