This study centres on science, aesthetics and ideology in Spain and Spanish America in the years 1680-1740. Catholic humanists began to move away from Scholastic philosophy and the aesthetics of cultism and conceptism in this period, which should be viewed as a bridge to the experimental phiosophy and neoclassical aesthetic of the later 18th century. The four main authors featured in this work were Hispanic humanists who embraced the via media - what Richard Popkin has called the third force of 17th-century thought - of epicurean atomists and moralists in their scientific and non-scientific writings. The influence of Bacon and Gassendi on the Spanish republic of letters - already visible in the writings of Sor Juana Ines de la Cruz (New Spain) and Gabriel Alvarez de Toledo (Spain) - continued into the third and fourth decades of the 18th century, when the philosophies of Newton and Vico appeared in the writings of Pedro de Peralta Barnuevo (Peru) and Francisco Botello de Moraes (Spain, Italy, Portugal).