De revolutionibus orbium coelestium
Researchers and scholars who write about their discoveries and ideas sometimes have profound effects on society. Scientists and philosophers are good examples because their new ideas can revolutionise the way people think and how they behave. Three of the best known examples of such a revolutionary effect are Nicolaus Copernicus, who wrote "De revolutionibus orbium coelestium" (1543); Charles Darwin, who wrote "On the Origin of Species" (1859); and Sigmund Freud, who wrote "The Interpretation of Dreams" (1899).