The Poussinists believed in the Platonic idea of the existence in the mind of ideal objects that could be reconstructed in concrete form by the selection, using reason, of elements from nature. For the Poussinists, therefore, color was a purely decorative addition to form and drawing (design or "disegno"), the use of line to depict form, was the essential skill of painting. Their leader was Charles Le Brun (died 1690), Director of the Academy, and their heroes were Raphael, the Carracci, and Poussin himself, whose severe and stoical works exemplified their philosophy. Their touchstones were the forms of classical art.