In the seventeenth century, the mathematical sciences were revised by the addition of analytic geometry and calculus, new quantitative laws of motion, new theories of vision, refraction, and color, and the extension of statics to pneumatics (studies of air, fluids, and gasses). Still, Kuhn argued that Aristotle and the medievals also understood the importance of observation and experimentation. What was new was not so much the addition of new fields or striking new discoveries, but a change in perspective—new ways of looking at old things.

Nicolaus Copernicus (1473–1543; also spelled Mikolaj Kopernick) was born in Toruñ, Prussia (in what is now Poland). He was educated in liberal arts, canon law, and medicine at the universities in Kraków, Poland, and Bologna and Padua, Italy. He received a doctorate in canon law from the University of Ferrara when he was 30. His uncle, the Bishop of Ermland, got him the post as canon of the cathedral of Frauenburg in 1497, and he also served as physician to his uncle.

Copernicus’ job as canon involved diplomatic work and administration of church estates. He knew Greek and translated Byzantine poetry into Latin. He was knowledgeable about economics and developed interests in astronomy and mathematics.

He became known for his astronomical observations and calculations, and in 1514 Pope Leo X asked him to help reform the calendar. Copernicus refused because he did not think enough was known about the motions of the Sun and Moon, although he is widely reported to have contributed to calendar reform, nonetheless.

Copernicus began developing his theories in 1512 and presented a short description of his system, Commentariolus, to a small group of friends. His major work, De Revolutionibus Orbium Coelestium Libri IV (1543) was published in the same year he died. At the time of his death, he also left a treatise on monetary reform, Monetae Cudendae Ratio, for the Prussian provinces of Poland. First printed in 1816, but written in 1526, this work advocated a uniform coinage, preservation of the quality of the coin, and a charge to the nobility for minting the coin. Copernicus anticipated “Gresham’s Law,” which states that debased money drives good money out of circulation.