Anaximander of Miletus

 610-546 BC Anaximander succeeded Thales as the master of the Milesian school of philosophy. fragments by other authors over time. The one surviving fragment for which he is given credit is as follows.

While little is known of his work, he is credited with writing the first philosophical work, On Nature. The book did not survive, and much of his writings have been recorded in various

Whence things have their origin,
Thence also their destruction happens,
As is the order of things;
For they execute the sentence upon one another
- The condemnation for the crime -
In conformity with the ordinance of Time.

 While most of the theories produced by Anaximander would be proven wrong over time, he was an important step in the evolution of thought because he attempted to produce a rational explanation of the cosmos. His flaws might mostly be attributed to the faulty understanding of the cosmos he held, based on the thinking of the day. If we forget what we know, and look at the nature of things from his world view, it is in fact a very reasoned argument he proposes.

 Central to his argument, is a dispute with the teaching of Thales, that water is the primary principle. It was a commonly held belief in his day that the four elements, (earth, wind, sea, and fire) were the foundation of the universe. He rejected that anyone of these held supremacy, and that they were bound together by what he called the Apeiron.

But it is not possible that infinite matter is one and simple ; either, as some say, that it is something different from the elements, from which they are generated, or that it is absolutely one. For there are some who make the infinite of this character, but they do not consider it to be air or water, in order that other things may not be blotted out by the infinite; for these are mutually antagonistic to one another, inasmuch as air is cold, water is moist, and fire hot; if one of these were infinite, the rest would be at once blotted out ; but now they say that the infinite is something different from these things, namely, that from which they come.
Aristotle. Physics (iii. 5 ; 204 b 22). 4th century BC.

 This concept of the Apeiron separates Anaximander from his contemporaries. The ultimate source of things was not tangible, it was an intangible force of nature that held all things together. The universe that we perceive was a product of that harmonious balance.

 To this end, Anaximander sees the world in a constant dynamic state. Mankind is no exception. This brings about the precursor to evolution.

Wherefore they (the Syrians) reverence the fish as of the same origin and the same family as man, holding a more reasonable philosophy than that of Anaximandros; for he declares, not that fishes and men were generated at the same time, but that at first men were generated in the form of fishes, and that growing up as sharks do till they were able to help themselves, they then came forth on the dry ground.
Aristotle. Plutarch (doxography). (Symp. viii. 730 E). 4th century BC.

 While the logic of Anaximander is well reasoned, where he falls short is in his description of the world and the universe around him. This is not to say that he was not influential on these topics, considered by many to be the Father of Cosmology, and to be the first to create a world map. On both of these counts, he was simply in error.

 His world map is described as follows; based on his limited understanding of the world.

  Likewise his description of geography, and the world as he knew it is limited to his knowledge of the world.

He [Anaximandros] says that the earth is a cylinder in form, and that its depth is one-third of its breadth. And he says that at the beginning of this world something [Diels] productive of heat and cold from the eternal being was separated therefrom, and a sort of sphere of this flame surrounded the air about the earth, as bark surrounds a tree ; then this sphere was broken into parts and defined into distinct circles, and thus arose the sun and the moon and the stars.
Plutarch. Doxography (Strom. 2 ; Dox. 579). 2nd century BC.

 This carries over to his cosmology of the universe, which could be considered the precursor to the Ptolemaic Universe.

Anaximandros et al.: The sun has the highest position of all, the moon is next in order, and beneath it are the fixed stars and the planets. 16 ; 345. The stars are carried on by the circles and the spheres in which each one moves. 20; 348. The circle of the sun is twenty-eight times as large as the earth, like a chariot wheel, having a hollow centre and this full of fire, shining in every part, and sending out fire through a narrow opening like the air from a flute. 21 ; 351. The sun is equal in size to the earth, but the circle from which it sends forth its exhalations, and by which it is borne through the heavens, is twenty-seven times as large as the earth. 24 ; 354. An eclipse takes place when the outlet for the fiery exhalations is closed. 25 355. The circle of the moon is nineteen times as large as the earth, and like the circle of the sun is full of fire and eclipses are due to the revolutions of the wheel ; for it is like a chariot wheel, hollow inside, and the centre of it is full of fire, but there is only one exit for the fire. 28; 358. The moon shines by its own light. 29 ; 359. The moon is eclipsed when the hole in the wheel is stopped.
Aetius. Doxography (Dox. 327.). latest 1st century BC.

 While the teachings of Anaximander ultimately fail to describe the nature of the universe, their triumph is in the methodology that lead to the conclusions. It is for this that Anaximander stands the test of time, and is remembered as one of the greatest minds in all of the many generations of mankind.