Aristotle (384–322 BC)

Many of the writings of the enormously influential Greek philosopher and scientist Aristotle (born in Stageira, 384 BC, died in Chalcis, 322 BC) played a fundamental role in the development of the discipline of geography. His geocentric model, which was perfected by Hipparchus and Ptolemy, considered Earth to be immobile at the center of the universe and was held by medieval Christianity as an incontestable truth. It had a huge influence on Western cosmology until the 16th century, when it was replaced by the heliocentric theory supported by Copernicus.

Aristotle believed the universe to be unique and finite and thought that nothing existed outside it. From his point of view, four elements (air, water, earth, and fire) combined to form the planet, while ether was considered to be the fifth element, which does not belong to this world: It is in the cosmos, which makes it immutable and thus differentiates it from Earth, where things continuously change.

Regarding the Earth, Aristotle asserted that its circumference was 400,000 stadia (1 stadion = about 185 meters) and presupposed the existence [Page 117]of an enormous southern continent that provided a counterweight to the Northern Hemisphere. He called this land Terra Australis Incognita, and its discovery was the aim of many explorative missions of the following centuries, such as that of Captain James Cook in 1768. Aristotle had a critical opinion about representing the ecumene (the habitable zone of the world) as a circle, but he deduced the roundness of Earth and the other celestial bodies by observing that other planets cast round shadows during eclipses. To confirm the validity of his theory, he reported that at different latitudes, stars were not seen at the same place in the sky. He was not sure about the existence of what is now called the Dead Sea, he considered the origin of the Danube River to be in the Pyrenees, and he believed the Caucasus to be the highest mountains in the East.

In his Meteorologica (Meteorology) text, Aristotle observed the distribution of animals and vegetation on Earth's surface and drew the conclusion that it was related to latitude, realizing how the poles and the equator could be considered the least favorable areas for living beings. He also made observations of atmospheric phenomena such as wind, hail, frost, and rainbows, trying to analyze the reason why they occur in certain moments or places. He also explained his ideas about topics such as the origins of the rivers and the salinity of the seas, floods, earthquakes, and astronomical questions such as comets, shooting stars, and the Milky Way.