"Around 1600 the English intellectual was more than half medieval, and around 1660 he was more than half modern", states ROSSI, who documents Francis Bacon's participation in this intellectual movement toward modernity, discussing his creative use, and reform of, medieval ideas. Rossi describes a number of instances in which Bacon's beliefs were taken from alchemical and magical sources; for example, his Sylva Sylvarum is a compilation of histories that culled many of its facts from the writings of Aristotle, Agricola, Delia Porta, Cardano, and others.