At the same time that they made advances in astronomy and physics, Europeans embarked on the pursuit of knowledge about unknown geographical regions. Because they were the first to acquire a large overseas empire, the Spanish pioneered these efforts. The Spanish crown sponsored many scientific expeditions to gather information and specimens, out of which emerged new discoveries that reshaped the fields of botany, zoology, cartography, and metallurgy, among others.

Plants were a particular source of interest because they offered tremendous profits in the form of spices, medicines, dyes, and cash crops. King Philip II of Spain sent his personal physician, Francisco Hernández, to New Spain for seven years in the 1560s. Hernández filled fifteen volumes with illustrations of three thousand plants previously unknown in Europe. He interviewed local healers about the plants’ medicinal properties, thereby benefiting from centuries of Mesoamerican botanical knowledge.

Other countries followed the Spanish example as their global empires expanded, relying both on official expeditions and the private initiative of merchants, missionaries, and settlers. The stream of new information about plant and animal species overwhelmed existing intellectual frameworks. Carl Linnaeus (1707–1778) of Sweden sent his students on exploratory voyages around the world and, based on their observations and the specimens they collected, devised a system of naming and classifying living organisms still used today (with substantial revisions).