The transition between the humanist and classicist period began during the 17th century, with humanists becoming scientists. For about a century, epochal works appeared in Latin from representatives of the sciences and philosophy: Galileo Galilei, Francis Bacon, René Descartes, Baruch Spinoza and Gottfried Leibniz. Among the Croatian Latinists of this period was Stephanus Gradius (1613–1683), a Dubrovnik diplomat at the Roman Curia who was curator and director of the Vatican Library. He wrote treatises on philosophy, theology, mathematics and physics, and speeches and songs. Among Gradius' best-known poems is "Prejasne Venetian Republic", which explored the troubles faced by his native city ("De laudibus Serenissimae Reipublicae Venetae et Patriae cladibus drought Carmen", 1675) in 315 hexameters, providing a striking description of the 1667 Dubrovnik earthquake.