Abel Sanchez (1917), subtitled "A Story of Passion," is a recreation of the biblical story of Cain and Abel. It tells the story of the relationship between two friends: Abel Monegro and Joaquin Sanchez. It all starts with Joaquin (Cain) trying to understand the uncontrollable jealousy he felt toward his friend Abel; a feeling Joaquin could trace to when they were infants. When Abel marries Helen, the woman Joaquin was in love with, the most violent and dark feelings are stirred within Joaquin's soul. The main theme of the novel is 'envy.' In this primitive emotion -envy- Unamuno sees not only the malady of individuals, but that of his own country: Spain. In addition, some sub-themes are interlaced and treated: love, hatred, sacrifice, faith, and the ancient quarrel of the sciences versus the arts.