Martinez wrote the Discourses toward the end of his life as a well-travelled professional artist who had studied and worked in Italy and the major artistic and literary centres of Spain; his ideas were especially enriched by his participation in the elevated cultural life of his native Aragonese school. His discussions on art offer anecdotal knowledge from his friendships with many of the principal artists of Spain's Golden Age, including Diego Velazquez and Alonso Cano, as well as writers and intellectuals of the period.
Martinez's text stands out for a nuanced humanism that is rare in practical treatises. Along with his original ideas on handling, pictorial aesthetics, and the vocation of painting, his work has even more affinities with philosophical discourses than with artists' practical instructional books. Zahira Veliz's introduction and notes provide historical context and situate Martinez's ideas in his rich cultural milieu.