Anaximander (ca.610 BC – ca.546 BC) was a philosopher who lived in Miletus, a city of Ionia in Asia Minor (Anatolia). He was a student of Thales. He succeeded Thales and became the teacher of Anaximenes and Pythagoras. He made a number of inventions, wrote treatises on geography, astronomy, mathematics and cosmography.
He speculated and argued about “the Boundless” as the origin of all that is. He originated the world-picture of the open universe, which replaced the closed universe of the celestial vault.
- Anaximander is considered to be the founder of scientific geography, for he was the first to draw a map of the entire known world (550 BC). His map was spherical, because that was how he conceived the Earth to be: a sphere floating freely in space.
- Anaximander invented the solar gnomon, or “sciotheres” (= shadow-chaser), an instrument, which could be used to determine midday, the solstices and the equinoxes. It could also be used to calculate the length of a day, the number of hours, and the exact time of day.
- He discovered the revolution of celestial bodies. He was the first to try to determine the sizes of the celestial bodies, the distances between them, and how they are positioned in space.
- Anaximander thought that all the celestial bodies, and therefore the Earth as well, had their origin in what he called the “apeiron”, a primal unity of unbounded matter. (This was a rejection of Thales’ theory that water was the primary substance.) This fundamental conception underlies his explanation of the creation of the universe.
- The very first organisms, he claimed, developed in the mud of seas which had dried out under the action of the sun’s rays; their skin was covered with spines, which they gradually lost as they continued to live on dry land, under the influence of the sun. Man, he thought, was surely born from other animals, because, while animals could find what they needed for their survival on their own, man by contrast required a long apprenticeship. In that primeval world, therefore, man could not have survived if he had been created and existed in his modern form.
Anaximander’s principal writings are: “On Nature”, “On the Fixed Stars”, “Geometric Surveying”, “Sphere”, “Map of Greece” and “Map of the World”