Anaximander

Anaximander
Region	Ancient Greece (Miletus)
Influenced by	Thales
Notable ideas	Apeiron as boundless origin
Main interests	Metaphysics; Cosmology; Cartography
School	Milesian school
Era	Pre-Socratic
Contributions	Early cosmology; First Greek world map; Natural philosophy
Influenced	Anaximenes; Heraclitus; Parmenides
Wikidata	Q42458

Anaximander (c.610–546 BCE) was an early Greek philosopher from the city of Miletus in Ionia (modern-day Turkey). A student and successor of the philosopher Thales, Anaximander was one of the first thinkers in the West to offer a naturalistic, rather than mythic, account of the world. He introduced the idea that the origin of all things is a boundless, indefinite principle (the Greek apeiron, meaning “infinite” or “unlimited”), instead of the familiar elements like water or earth. He also made pioneering contributions to early cosmology, geography, and biology: for example, he argued that the Earth floats unsupported in space, drew one of the first maps of the known world, and suggested natural processes for the origins of life. Although his own writings have been lost, later accounts credit him with a foundational role in moving Greek thought toward scientific explanation.

Early Life and Education

Anaximander was born around 610 BCE in Miletus, a major Ionian Greek port city on the Aegean coast of Anatolia. According to later sources, he was the son of Praxiades. Not much is known about his childhood, but tradition holds that he studied under or worked closely with Thales of Miletus, the famed predecessor who taught that water was the first principle. Anaximander may even have been related to Thales (some accounts call Thales his uncle). In any case, Anaximander became a leading figure in what is often called the Milesian school of philosophy, centered in Miletus.

Anaximander is said to have succeeded Thales as head of this school. He traveled widely in the Aegean region; for example, he is credited with organizing a Greek colony (usually identified as Apollonia) on the shores of the Black Sea. He also journeyed to Sparta in Greece, where tradition says he set up a gnomon, or simple vertical sundial, to mark the noon shadow and study the movement of the sun. These travels suggest that Anaximander was ambitious and respected in his time. Ancient writers describe him as solemn in manner and fond of elaborate garments.

He lived into old age. One report notes that he was about 64 when he died, placing his death around 546 BCE (during the tyrannies of his Era). A bronze statue of Anaximander was erected in his honor at Miletus while he was still alive, underscoring the esteem in which he was held. By Anaximander’s time, the tradition of airing ideas in writing was just beginning; in fact, Anaximander is often credited as the first Greek philosopher to compose a prose treatise (reportedly titled On Nature) rather than relying solely on oral teaching.

Major Works and Ideas

Only one brief fragment of Anaximander’s writing survives (a single sentence preserved by later commentators), and most of our knowledge of his thought comes from later summaries. Still, this fragment, along with reports by Aristotle, Theophrastus, and Byzantine commentators, allow reconstruction of several of Anaximander’s key ideas.

The Apeiron and Fundamental Principle

Anaximander’s most famous concept is the apeiron—a Greek word meaning “boundless” or “indefinite.” He proposed that all things arise from and return to this apeiron, rather than from one of the familiar four elements (earth, water, air, fire). The apeiron is described as infinite, eternal, and undefined. It was neither water nor air nor any specific thing we can name, but a sort of primal substance without edges or limits. Because it is unlimited, the apeiron has no beginning or end; Anaximander argued that if it had a beginning, it would have a limit, which contradicts its nature. Thus the apeiron must be both “unborn and indestructible.”

From this boundless origin, the many opposite qualities of the world (hot and cold, wet and dry, etc.) emerge and later neutralize each other. Anaximander is known to have said that all things come into being from the apeiron “according to necessity” and that they pay “penalty and retribution” to one another for the injustice of their generation. In loose terms, he meant that when one thing gives rise to another, some kind of cosmic balance or justice is maintained. For example, the dry evaporates to give rise to the wet, then must return to dryness; the warm and cold, or the light and dark, follow cycles of change. This poetic idea of “injustice” should be understood not as moral wrongdoing but as a way of saying that every process has a compensating reverse process. In modern words, one might compare it to simple conservation or balance: if fire dries things out, then it in turn must be quenched by water; if one element becomes too dominant, natural processes act to restore the others.

Anaximander gave a logical argument for why the apeiron must be the first principle. He noticed that the observable elements (water, air, fire, earth) have contrasting properties. If, for example, water alone were infinite, it might eventually overwhelm everything else; similarly, an infinite fire or infinite air would destroy its opposites. Since none of these visible elements has done so (the world still contains all of them), Anaximander concluded that the true origin of things cannot be one of the familiar elements, but something beyond them – the indefinite apeiron. This line of reasoning, recorded by Aristotle, hints at an abstract, rational approach: Anaximander was essentially applying a kind of thought experiment and logic to the question of origins, seeking a principle more general than any known substance.

Cosmology and Astronomy

Anaximander went beyond abstract principle to sketch a detailed model of the cosmos. He envisioned an “open” universe without a solid dome overhead or mythical heavens; in his view, the Earth simply floats in space. Contrary to the common mythic image of the sky as a solid vault covering a flat earth, Anaximander’s universe was finite but unbounded in his own way.

He described the Earth as a roughly cylindrical shape (like a short column or a drum). The top of the cylinder was a flat, circular disc – this was the inhabited world where people live. The cylinder’s thickness (height) was about one-third of its diameter, according to one ancient report. Because this cylinder stood upright with its flat face at the top, the world’s surface was effectively a flat circle. Importantly, the Earth (this cylinder) floats in the middle of the cosmos and is not resting on anything like water or pillars. It remains “fixed in place” because it is exactly centered – equally distant from the “edges” of its environment – so there is no natural inclination for it to move up, down, or sideways. In simpler terms, he argued that a balanced, symmetrical planet has no reason to drift in any particular direction, so it stays still. This was a revolutionary idea at the time: it broke with the traditional view that the Earth had to be supported by something or else would fall.

Above and around the Earth, Anaximander placed the Sun, Moon, and stars on thin, hollow rings or wheels. Each such wheel contained fire that was normally hidden from sight by opaque material, except through a small hole or vent. For instance, he imagined the Sun as a large ring 27 times the Earth’s diameter, burning inside it but visible to us through a gap. When this vent lined up to point at Earth, we see a disk of bright light (daytime for that region); when it turns away, that region is dark. Similarly, he pictured the Moon as a somewhat smaller ring (about 19 times Earth’s diameter) with its own interior fire. The spots and phases on the Moon’s face, and even eclipses of the Sun or Moon, were explained as the effect of these holes opening or closing. (For example, a solar eclipse occurred when the vent in the Sun’s ring was blocked, and lunar phases occurred as we saw more or less of the vent in the Moon's ring.)

The stars formed other, even smaller fiery rings or wheels, each with its own vent, and they all moved around the Earth in full circles. In Anaximander’s scheme, the Sun, Moon, and stars all revolved daily from east to west. He also believed these heavenly bodies were at different distances: for instance, the Sun’s wheel had a much greater radius than the Moon’s, and the stars were closer still. Although this was incorrect in modern terms (we now know the stars are vastly farther away), his attempt to give relative sizes shows an effort at quantitative reasoning. One ancient account suggests he assigned ratios (9:18:27) to the radii of the stars, Moon, and Sun circles relative to the Earth.

Overall, his cosmic model was remarkable for freeing humans from the mythic idea of a solid dome or fixed heavens. By picturing an infinite, open space with the Earth floating in the center, Anaximander set the stage for later astronomy. Centuries after him, the concept of a spherical Earth and a sun-centered system would emerge, but Anaximander’s move to view the cosmos as rational and law-governed was a key early step.

Natural Philosophy and the Origin of Life

In addition to the cosmos at large, Anaximander pondered the origin of living things from natural causes. He imagined that life began in the moisture (wet mud) of early Earth. In his view, the young Earth was covered by a primordial ocean or vapor that gradually dried. As the waters receded under the heat of the sun, the first creatures emerged from the slime. He described these early animals as having thorny or spiny skins – perhaps like shells – which protected them on the wet ground. Once they moved to drier land and their protective coverings began to break or fall away (under prolonged sun exposure), they lived their “second life” in a new environment.

Anaximander went further to apply this to humans: he speculated that ancestral humans could not have been fully formed at birth as they are today. A newborn baby takes many years of care before it can survive, so he reasoned that early humans must have been born within other creatures that could protect them until maturity. In practical terms, this led him to suggest that humans first developed inside fish-like or amphibious animals. Only after a long period of adjustment, as the environment became more hospitable, would the human child emerge to live outside. This idea, that we once passed through or came out of another species, has some parallels with evolutionary thinking (though it is not “evolution” as we know it); it is notable as one of the earliest recorded suggestions that species change over time and adapt to their surroundings.

Geography and Cartography

Anaximander’s curiosity about the natural world extended to mapping the Earth itself. He is traditionally credited with drawing one of the first maps of the known world (the “inhabited earth”) in ancient Greece. This would have been a map of the Mediterranean region and surrounding areas known to the Ionians, useful for a seafaring and colonial people. No copy of Anaximander’s map survives, but ancient writers note that after him his Milesian colleague Hecataeus further refined the map. The idea of charting the world in a systematic way was novel in Greek thinking, and Anaximander’s map would have organized knowledge of places, distances, and directions in one view.

To aid in such surveys and timekeeping, Anaximander is also said to have introduced the gnomon to the Greeks. A gnomon is simply a vertical stick or column placed upright on the ground; as the sun moves across the sky, the shadow cast by the gnomon shifts. By marking the length and direction of its shadow at noon, one can track the solstices and equinoxes and even roughly determine latitude. Anaximander reportedly set up a gnomon in Sparta to demonstrate the change of seasons. This was an important step toward astronomy and cartography: it allowed more precise estimation of the lengths of months or the position of the sun, and it shows Anaximander applied practical geometry to natural problems.

In summary, Anaximander’s major contributions included:

• The idea of apeiron as the source of all things, an endless primal substance beyond the ordinary elements.
• A cosmological model in which the Earth floats free at the center of an open universe, bound by symmetry rather than physical supports; and a description of the Sun, Moon, and stars as fiery rings with vents causing light and dark.
• Early astronomy with numeric estimates of cosmic distances (ratios for the celestial spheres) and explanation of eclipses and lunar phases.
• A prototype of biological theory suggesting that life arose from the sea and that humans originally developed from other creatures (proto-evolutionary thinking).
• Foundations of geography and cartography by sketching the first map of the known world and introducing instruments like the sundial gnomon to measure time and geography.

Methodology

Anaximander’s approach marked a clear departure from mythological explanations toward rational inquiry. He is often regarded as the first known philosopher to propose that nature operates according to laws or consistent principles rather than the whims of gods. He sought a first principle (Greek archê) behind the phenomena, and he used abstract reasoning and analogies in lieu of elaborate experiments. In contrast to telling stories of divine intervention, Anaximander asked what single “stuff” could underlie all changes, and how observable events fit into a systematic picture.

His surviving fragment and later reports show that he worked in what we would call a scientific spirit. For example, his argument that the apeiron must have no origin or end is an early use of logic to infer properties of an unseen cause. His argument for Earth’s stability – that something perfectly balanced will naturally stay at rest – is a geometrical or symmetry argument applied to the world. These are not idle myths but something like primitive hypotheses tested by thought. Anaximander also employed simple empirical observations: placing a gnomon and watching its shadow or blowing on one’s hand (as one of his successors, Anaximenes, is said to have done) to understand heat.

We can say his method was to generalize from specific facts (like the behavior of water and air) to a universal explanation, and also to imagine models that fit nature (such as cosmic wheels of fire). In doing so, he treated the world as a coherent system that could be grasped by reason. This made him a forerunner of later scientific thinkers, though he did not have the benefit of systematic measurement instruments, formal proof, or experimental procedure as in modern science. His writings (in prose) suggest attempts at clear argumentation; for example, Aristotle praised him for treating even “cosmic justice” in a law-like fashion. Compared to poets and storytellers of his time, Anaximander stood out for trying to “explain the sky by something else than gods.”

In the historical context, Anaximander’s method was part of the Milesian tradition of natural philosophy, which searched for a single originating principle. He took Thales’ approach further by abstracting that principle beyond any tangible element. He is sometimes called the first metaphysician in the Western philosophical tradition for this very reason: he posited an underlying reality that is not directly observable. At the same time, he retained concrete observation, as in his mapping work and sundial use. Thus his method combined empirical insight and speculative reasoning in a way that became the hallmark of philosophy and early science.

Influence

Anaximander’s ideas reverberated through Greek thought and beyond. In the immediate line of succession, he influenced later Milesian philosophers. Anaximander’s associate (and perhaps pupil) Anaximenes of Miletus adopted the quest for a single principle but proposed air instead of the indefinite apeiron. In this way the Milesian school—Thales, Anaximander, Anaximenes—set a template of rational inquiry that contrasted with mythic storytelling.

Later Greek philosophers and scholars, such as Aristotle, Theophrastus, and the Neoplatonist Simplicius, studied and preserved reports about Anaximander. Aristotle treated him as a pioneer who boldly broadened the concept of origin. Aristotle also took up Anaximander’s idea of the Earth’s balance as a valid argument for a freely floating planet (even though Aristotle himself later favored a spherical Earth). The notion of the apeiron as an eternal origin may have resonated with Plato’s idea of transcendent Forms: both views posit a reality beyond the concrete world. Some scholars speculate that Anaximander’s apeiron influenced Plato’s notion of the “indefinite dyad” behind the Forms, or Aristotle’s idea of a single Prime Mover. At the very least, Anaximander introduced a concept of the infinite that prefigures later metaphysical discussions.

In geography and science, his impact was also significant. By drawing a map of the world and introducing instruments, he laid groundwork for Greek geography; later geographers like Hecataeus built on this foundation. In astronomy, Anaximander stands as one of the first recorded thinkers to try to measure or calculate the cosmos. Although he was soon surpassed by figures like Pythagoras, Plato, and eventually Copernicus, the tradition he started of using reason to understand nature was maintained through the centuries.

His notion of origin and evolution in biology has intrigued modern scholars as an ancient precursor to evolutionary thinking. Nothing like rigorous Darwinian theory was possible in his time, of course, but the seeds of scientific curiosity about life’s beginnings can be traced back to him. Natural historians of the Roman and medieval world sometimes mentioned his ideas, keeping his name alive as a founding figure. In the Renaissance and Enlightenment, Anaximander was admired by some for anticipating scientific thinking.

Overall, Anaximander’s blend of abstract theory and practical observation set a standard. Historians of science often call him the first true “scientist” or “cosmologist” in Western history. He is credited with helping shift Greek inquiry from supernatural accounts to natural law. In general philosophy, he launched the project of explaining the world in terms of underlying principles, a project that would dominate centuries of scholarship.

Critiques and Debates

Like any early thinker, Anaximander’s work was not without problems, and later critics have noted both limitations and puzzles in his theories. One obvious gap is that the apeiron itself is never clearly defined. Even ancient skeptics and modern scholars remark that it’s not obvious what a “boundless” substance really is or how exactly it behaves. Since it cannot be observed or characterized (by definition it has no limits), questions remain: How could a world come out of something infinite? Aristotle and others complained that Anaximander gave the name apeiron but did not explain much more about it. Is it material, is it something like space, or something else entirely? This vagueness has allowed centuries of debate over Anaximander’s true meaning.

In his cosmology, many of Anaximander’s details were empirically wrong. The cylindrical Earth is not how the planet is shaped, and his relative distances to the sun, moon, and stars were wildly off. Some of the numbers he gave (like the 9:18:27 ratio of celestial radii) cannot be based on actual measurement and likely reflect guesswork or a numerological idea. From a modern perspective, imagining the Sun and Moon as hollow wheels and explaining phases by vents is fanciful. Even in ancient times, some scholars found these images poetic rather than literal. A more charitable view is that Anaximander was formulating a visual model to make sense of observational data: for instance, the fact that the Moon goes dark (load) or that solar eclipses occasionally happen needs explanation, and he found one. But the lack of empirical support for these specifics left room for correction by others, as indeed happened (later astronomers developed quite different models).

The poetic statement about things paying penalty for “injustice” to each other has puzzled readers. It suggests a moral or legal metaphor in cosmology – an idea that the universe operates by a kind of equitable rule of give-and-take. Some see this as an early hint of law-like behavior in nature, while others see it as too metaphorical to be scientific. That discussion exemplifies a broader point: Anaximander lived in a world where science and myth were not sharply separated, so it’s not always easy to interpret whether he meant his ideas in a strict naturalistic sense or as a kind of philosophical poetry. His followers and later commentators often had to guess.

In later history, Anaximander also faced the criticism that he did not always base theories on observation in a modern sense. He used clever reasoning, but often without experimental confirmation. For example, the argument that the Earth rests in the middle because it cannot move to two directions at once is logical, but it is not derived from data the way contemporary science would require. On the other hand, for his era it was a bold move beyond mere storytelling.

Overall, the critiques of Anaximander tend to revolve around the limited information we have and the ambiguities of his lost work. Much of what he actually wrote is unknown, so some scholars even debate how much of the surviving accounts reflect his own ideas and how much are later interpretations. In this sense, Anaximander is a figure of scholarship debate: each generation of historians reexamines his lone surviving verses and fragments for new meaning. But no matter the criticisms, all agree on his importance as a transitional thinker.

Legacy

Anaximander’s legacy lies in the innovations he introduced and the questions he first asked. In the history of Western thought, he is often remembered as the first person to conceive a general theory of the universe – a proto-cosmologist and metaphysician. Ancient sources acclaim him as the first to write in prose, the first geographer (by drawing a world map), and the first to boldly speculate about the cosmos in logical terms. These “firsts” made him a model for later natural philosophers.

His concept of the apeiron had a long afterlife in philosophical discussion about the infinite. Medieval and Renaissance thinkers referenced Anaximander among the pre-Socratics when debating the existence of an infinite universe or a nonphysical first cause. In modern science history, he is often paired with Thales in the narrative of the “Birth of Science” in ancient Greece. While Aristotle and Plato supplanted the Milesian ideas, they nonetheless owed a debt to the Greek spirit of inquiry that Anaximander exemplified.

In geography and astronomy, the very practice of mapping or measuring had an early boost from his work. For instance, his use of the gnomon to track solstices is one of the earliest recorded meteorological/astronomical measurements. Centuries later, the idea of mapping the world would expand enormously, but it began with lines like those Anaximander conceived. Today geographers sometimes honor him as a pioneer of their field.

Even outside academia, Anaximander is occasionally celebrated. He has been called “the first scientist” or “first philosopher” by various authors, though such titles are natural exaggerations. In science communities, he is cited as an example of early scientific reasoning. His name adorns craters on the Moon and Mercury, recognizing his contributions to astronomy.

While many of his specific ideas have been overturned by modern science, the boldness of his vision retains respect. He showed that humans can inquire about the nature of things and the universe without immediate recourse to the divine. In that sense, he paved the way for later philosophical and scientific advances. His notion of a hidden principle underlying reality finds echoes in many subsequent traditions (from Plato’s world of forms to modern physics’ search for fundamental laws). Anaximander’s enduring significance is as a symbol of the transition from mythos to logos – from myth to reason – in human thought.

Selected Works

No works of Anaximander survive intact. He is said to have written a book called On Nature (or Peri Physeos in Greek), likely a prose treatise on the cosmos and natural phenomena. All that remains from this work is one sentence fragment concerning the apeiron, preserved by later philosophers. Ancient doxographers also mention other titles (perhaps On the Fixed Stars, Geometric Surveying, Sphere, or maps of Greece and the world), but these are not extant and may reflect sections of On Nature rather than separate books. In practice, what we call “Anaximander’s ideas” are reconstructed from quotations and reports by later writers like Aristotle, Hippolytus, and Simplicius. Thus, to study Anaximander’s works today means to study those secondary accounts.

Because none of his own writing is available, modern editions of his “fragments and testimonia” have been collected by scholars (for example, by Hermann Diels and others) under the title Die Fragmente der Vorsokratiker. In these collections, fragment απ 12* (from Simplicius) is the famous brief line about the apeiron as source and limit of all worlds. Students of philosophy and classics learn this fragment by heart, as it is the sole clear witness of Anaximander’s own voice. Beyond that, any attribution of ideas to him depends on cross-referencing ancient sources carefully. In summary, Anaximander’s selected works might be listed as:

• On Nature (Περὶ Φύσεως) – lost prose treatise; source of fragment about the apeiron.
• Geometry, Cartography, Astronomy (titles uncertain) – possibly sections or additional treatises on these subjects, known only through references.

Because all titles and content are uncertain, an article or book on Anaximander typically cites “fragments” or later accounts rather than actual writings.