Until about 1930 Borges's main creative medium was poetry: laconic free-verse poems which evoked scenes and atmospheres of old Buenos Aires or treated timeless themes of love, death and the self. He also wrote many essays on subjects of literary criticism, metaphysics and language, essays reminiscent of Chesterton's in their compactness and unexpected paradoxes. The lucidity and verbal precision of these writings belie the agitated conditions of avant-garde polemic and playfulness under which most of them were composed. During these years Borges was content to seek expression in serene lyric images perhaps too conveniently abstracted from the surrounding world and have all his speculations and creations respond primarily to the need for a new national literature as he saw it. The years from 1930 to 1940, however, brought a deep change in Borges's work. He virtually abandoned poetry and turned to the short narrative genre. Though he never lost his genuine...