 Carlos Sigüenza y Góngora (1645–1700) was a remarkable scientist, historian, and philosopher. He taught astronomy and mathematics at the Royal and Pontifical University of Mexico, and he became known for his opposition to the belief that comets were harbingers of catastrophes. In his book, Libra astronómica y filosófica (1690 [1984]), Sigüenza y Góngora was one of the first intellectuals in New Spain to examine the advancements of Galileo Galilei, Descartes, and Kepler with scientific rigor. He was also well versed in pre-Columbian thought and culture, and rescued the moral and political practices and beliefs of the ancient Aztecs, presenting them as an example to live by.