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The Ancient Greek Philosopher Anaximander of Miletus

My writing interests are general, with expertise in science, history, biographies, and how-to topics. I have written over 70 books.

Anaximander holding a sundial from a third century AD Roman mosaic.

Anaximander holding a sundial from a third century AD Roman mosaic.

Who Was Anaximander of Miletus?

Anaximander of Miletus was a student and associate of the first philosopher, Thales, in the ancient Greek city of Miletus. Anaximander has been credited with many accomplishments: the introduction of the gnomon into Greek culture and the set up of a sundial in Sparta; first to mark the solstices and equinoxes; first to draw an outline of the earth and sea; and first to define the Indefinite (or apeiron) as the principle and fundamental element of nature. He was also the first of the Greeks to write a book in prose, which, except for a small fragment, has been lost to history. His work was not limited to science and philosophy; he was also involved in politics and was the leader of one the Milesian colonies.

Though few details of his life are known, it is believed he was born in Miletus, a thriving ancient seaport city on the western coast of modern-day Turkey around 610 BC. Anaximander was the son of Praxiades and was a student of Thales, the first Western philosopher. Anaximander died around 547/546 BC based on an account given by the second century BC Greek scholar and historian, Apollodorus.

The Difference Between Science and Philosophy

When studying the ancient Greek thinkers, it is natural to place them in specific categories including philosopher, astronomer, biologist, or physician; however, two thousand years ago these distinctions didn’t exist. The great minds of the ancient world seldom limited themselves to a specific topic of study, as we do today. For them, there was no distinction between what we now call “science” and “philosophy.” The line between science and philosophy can often be a blurred one, and roughly speaking, the difference is that science depends on observations and experimentation and it produces a “result,” whereas philosophy depends on logical arguments and doesn’t necessarily have to produce a “result.”

The area of philosophy known as natural philosophy, which is the study of nature, bridges the gap between philosophy and science. This is the area of study and speculation that nearly all of the early Greek philosophers delved into. It was not until the time of Socrates that philosophers began to ponder the questions associated with the human condition, known as moral philosophy. It was then that the difference between science and philosophy became more apparent.

The Gnomon and Sundial

The gnomon is one of the first scientific instruments used in astronomy. This simple instrument consists of a vertical rod placed in the ground that measures the sun’s position and direction as it traverses the sky. The ground around a gnomon can be calibrated to give the time of day, as well as the position of the sun on the ecliptic, thus the season of the year is known. When the gnomon was incorporated into a sundial it became a clock for the early Greeks. Ancient writers say that Anaximander set up and demonstrated a sundial in the leading Grecian city-state of Sparta. Rightly or wrongly, Anaximander has been credited with the introduction of the sundial into Greek culture. Some say the credit should be given to Thales as sundials were known to the early Egyptians and he may have introduced it to the early Greeks.

A sundial. The gnomon is the part that casts the shadow.

A sundial. The gnomon is the part that casts the shadow.

Map of the World

According to the ancient geographer Agathemerus, Anaximander was one of the first Greek geographers to make a map of the known world. He wrote, “Anaximander the Milesian, a disciple of Thales, first dared to draw the inhabited world on a tablet; after him, Hecataeus the Milesian, a much-travelled man, made the map more accurate so that it became a source of wonder.” Local maps in the ancient world were not a new idea; however, where Anaximander innovated was that his map was for the known world. He probably drew his map for a very practical reason, to enhance trade from Miletus to other Greek colonies around the Mediterranean and Black Seas.

Though the map does not survive, scholars envision a flat map with the border regions of Europe, Asia, and Libya, separated by the Nile and Phasis (now Rioni) Rivers. According to Agathemerus, a fellow Milesian and world traveler, Hecataeus improved upon the map. Anaximander probably obtained geographical reports from mariners who landed in the commercial port of Miletus. He also gathered his geographical information from his own travels, as it was said that he led a colonizing expedition to Apollonia, presumably the city on the Black Sea, as well as during his sojourn to Sparta.

A modern reconstruction of Anaximander’s map of the world.

A modern reconstruction of Anaximander’s map of the world.

The Indefinite or Unbounded

Like the other philosophers of his age, Anaximander sought the element from which all things were derived, the arche, or beginning. For his predecessor, Thales, the element that constituted all things was water. Anaximander’s view was more nebulous and all-encompassing with an unlimited or unbounded primordial mass or “apeiron,” which was not subject to decay and was a perpetual source. The sixth century AD philosopher Simplicius of Cilicia gives an account of Anaximander’s originative substance: “Of those who say that it is one, moving, and infinite, Anaximander, son of Praxiades, a Milesian, the successor and pupil of Thales, said that the principle and element of exiting things was the apeiron, being the first to introduce this name of the material principle. He says that it is neither water nor any other of the so-called elements, but some other apeiron nature, from which come into being all the heavens and worlds in them.”

Anaximander argues that the primal substance water cannot account for all the opposites found in nature; namely, water can only be wet, never dry, not making it a primary substance. He proposed that this substance not detectable by humans, the apeiron, could explain the opposites he observed in the world.

Aristotle wrestled with Anaximander’s concept of the apeiron, wring in Physics (203), “All the physicists make the infinite a property of some other nature belonging to the so-called elements, such as water or air or that which is intermediate between these.” Later scholars have interpreted Anaximander’s primordial element to be “without boundary, limit, definition.” It represented the original world-forming substance.

The Fragment of the Book of Anaximander

Anaximander has been credited with writing the first book of natural philosophy titled On Nature. Though the book has been lost, Theophrastus, Aristotle’s student and successor, and the fourth century AD biography Diogenes Laertius and others referenced Anaximander’s book. Other writers have referenced the original text of On Nature or perhaps Theophrastus’ recounting of the subject matter to give descriptions of Anaximander’s work on fields ranging from astronomy to geography to biology.

Simplicius records what is believed to be a direct quote of Anaximander in his commentary on Aristotle: “…Some other apeiron nature, from which come into being all the heavens and the worlds in them. And the source of coming-to-be from exiting things is that into which destruction, too, happens, ‘according to necessity; for they pay penalty and retribution to each other for their injustice according to the assessment of Time.’ ” The exact meaning of these few words has been discussed and debated for millennia. Since the ancient Greeks did not use quotation marks in their writing it is not clear if Simplicius is quoting word for word or simply paraphrasing Anaximander’s words. L. Tarán, in the Dictionary of Scientific Biography, offers a readable paraphrase of the fragment, “All things pass away into that from which they took their origin, the infinite, as it is necessary; for they make reparation to one another for their injustice in the fixed order of time.”

Though many interpretations have been written for this extant fragment, one thing that is clear is that Anaximander believed in an impersonal law that governed the workings of the universe. This fragment gives only a fleeting glimpse of his thoughts, but luckily, other ancient writers who had access to his works give us a clearer understanding of his views on the origins and workings of the cosmos.

Formation of the Cosmos

Like the other early philosopher from Miletus, Anaximenes, Anaximander’s view of the origin and order of the cosmos was different from Thales, who thought the fundamental substance of the world was water. The younger of the three, Anaximenes proposed that the arche, or the original source, was air. Anaximander’s formulation of the origin of the cosmos (cosmogony) was rather elaborate and took into account the origin and workings of the earth, sun, moon, and stars. Anaximander describes the formation of the universe starting with the earth, then the sun, the moon, and stars. Pseudo-Plutarch describes Anaximander’s account of creation as such, “He says that which is productive from the eternal of hot and cold was separated off at the coming-to-be of this world, and that a kind of sphere of flame from this was formed round the air surrounding the earth, like bark around a tree. When this was broken off and shut off in certain circles, the sun and the moon and the stars were formed.”

In his own writing, Hippolytus gives more details of Anaximander’s view of the earth: “Its shape is curved, round, similar to the drum of a column; of its flat surfaces we walk on one, and the other on the opposite side.” The cylindrical earth stands still in space according to Aristotle’s rendition, in which he wrote, “It is impossible for it to move simultaneously in the opposite direction, so that it stays fixed by necessity.”

Anaximander’s view of the earth, stars, moon, and sun.

Anaximander’s view of the earth, stars, moon, and sun.

Formation of the Heavenly Bodies

Anaximander’s account of the formation of the heavenly bodies and how they move about the earth is given by Hippolytus: “The heavenly bodies come into being as a circle of fire separated off from the fire in the world, and enclosed by air. There are breathing-holes, certain pipe-like passages, at which the heavenly bodies show themselves; accordingly, eclipses occur when the breathing-holes are blocked up. The moon is seen now waxing, now waning according to the blocking or opening of the channels. The circle of the sun is 27 times the size of the earth; that of the moon, 18 times; the sun is highest; and the circles of the fixed stars are lowest.” The description of the heavenly bodies explains why there are eclipses and moon phases, and defines the separation of the sun, moon, and stars from the earth.

A similar description comes from Aetius, “Anaximander [says the sun] is a circle of 28 times the size of the earth, like a chariot wheel…full of fire, and showing the fire at certain point through an aperture as though through the nozzle of a bellows.” In his description, “The sun is equal to the earth, but that the circle from which it has its breathing-hole and by which it is carried 27 times the size of the earth,” and that the heavenly bodies, “are carried by the circles and spheres on which each one goes.”

In a second recounting of Anaximander’s view of the cosmos, the diameter of the wheel that the sun, moon, and stars revolve about are different by one unit. In Aetius’ version, the sun is a circle 28 times the earth, whereas in his writings, Hippolytus specifies a diameter of the sun wheel of 27 times that of the earth. Discrepancies in ancient texts are common and reveal just how fragile is our understanding of what the true ideas of the ancient philosophers really were.

Anaximander’s view of the relationships and size of the heavenly bodies relative to the earth.

Anaximander’s view of the relationships and size of the heavenly bodies relative to the earth.

Rain, Clouds, and Storms

Anaximander, through Hippolytus, Seneca, and Aetius, provides his explanation of meteorological phenomena—rain, clouds, winds, thunder, and lighting. “On thunder, lightning, thunderbolts, whirlwinds and typhoons, Anaximander says that all these things occur because of wind: for whenever it is shut up in a thick cloud and then bursts out forcibly, through its fitness and lightness, then bursting makes the noise, which the rift against the blackness of the clouds makes the flash.” The passage suggests that Anaximander shared the Ionian way of accounting for meteorological events. The emphasis on wind as a prime mover suggests an implicit form of agreement with his fellow Milesian philosopher Anaximenes, who states that air, the constituent of wind, is the primal source, and both give the same explanation of lightning.

Anaximander believed that the earth was in the process of drying up. This conclusion, shared by other thinkers of his day, is indicated in the passage from Aristotle’s Meteor, “For first of all the whole area round the earth is moist, but being dried by the sun the part that is exhaled makes winds and turnings of the sun and moon, they say, while that which is left is sea; therefore they think that the sea is actually becoming less through being dried up, and that some time it will end up by all being dry…of this opinion, as Theophrastus relates, were Anaximander and Diogenes.” Those who believed that the sea was drying may have been influenced by local examples of the process, which were conspicuous around sixth-century Miletus.

Anaximander and Infinity

The Origin of Man

The view that man originated in the sea was held by Anaximander, as told by Censorinus, “Anaximander of Miletus conceived that there arose from heated water and earth either fish or creatures very like fish; in these man grew, in the form of embryos retained within until puberty; then at last the fish-like creatures burst and men and women who were already able to nourish themselves stepped forth.” This is the only information we have on Anaximander’s thoughts on the origins of humans. This view as not out of line with the early thinkers. Perhaps the observation being the theory came from mud-flies and sand-worms that emerged from the hot sand and mud at the edge of the sea. Anaximander’s origin story of man is the first known based not on mystical or religious beliefs, but rather based on a rational explanation, however erroneous.

A lunar impact crater located near the northwest limb of the moon named after Anaximander.

A lunar impact crater located near the northwest limb of the moon named after Anaximander.


The man we know as Anaximander of Miletus, who lived so many centuries ago, opened the door for those who followed to develop many fields of study in science and philosophy. Though he was not the first Western philosopher—that title goes to Thales—he was the author of the first surviving written fragment of Western philosophy. His map of the world made him one of the first geographers. In astronomy he developed a model to describe the mechanics of the stars, moon, and sun as they move about the earth. Anaximander combined his knowledge of astronomy and geometry to introduce the gnomon and sundial to the Greeks, allowing them to keep track of time and seasons. Though what we know of Anaximander of Miletus all comes from secondary sources, we do know enough about the man to declare he was one of the greatest thinkers of antiquity and laid the cornerstone of the Western world-picture.


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© 2021 Doug West