This book traces the further development and emergence of American philosophy, particularly Naturalism and Pragmatism, against the backdrop of still-dominant Hegelian philosophy, during the third decade of the 20th century, through the addresses and biographies of the presidents of its oldest and largest philosophical society. Of special interest is the previously unpublished presidential address of Henry Walgrave Stewart, second president of the Pacific Division of The American Philosophical Association. The work contains the biographies, photographs, and addresses of 24 past presidents, and photographs and addresses of others. No other publication has collected the presidential addresses of this, the largest society of philosophers, during its third decade of existence, and in no other publication are the biographies and photographs of all of its presidents available. While some histories of this period in 20th century American philosophy have been written, and while some collections of articles by philosophers exist which include writings of some of these individuals, none has concentrated on a representation of the leadership of