Editing Anaximander (section)

== Theories ==

[[File:Anaximander.jpg|thumb|upright|Detail of [[Raphael]]'s painting ''[[The School of Athens]]'', 1510–1511. This could be a representation of Anaximander leaning towards [[Pythagoras]] on his left.<ref>This character is traditionally associated with [[Anicius Manlius Severinus Boethius|Boethius]], however his face offering similarities with the relief of Anaximander (image in the box above), it could be a representation of the philosopher. See {{cite web |url=http://www.mlahanas.de/Greeks/SchoolAthens2.htm |title=Raphael's School of Athens (2/2) |access-date=2007-02-14 |url-status=dead |archive-url=https://web.archive.org/web/20070214002240/http://www.mlahanas.de/Greeks/SchoolAthens2.htm |archive-date=2007-02-14 }} for a description of the characters in this painting.</ref>]]

Anaximander's theories were influenced by the [[Greek mythology|Greek mythical]] tradition, and by some ideas of [[Thales]]&nbsp;– the father of [[Western philosophy]]&nbsp;– as well as by observations made by older civilizations in the Near East, especially Babylon.<ref>C. Mosse (1984) ''La Grèce archaïque d'Homère à Eschyle''. Édition du Seuil. p236</ref><ref name=":0" /> All these were developed rationally. In his desire to find some universal principle, he assumed, like traditional religion, the existence of a cosmic order; and his ideas on this used the old language of myths which ascribed divine control to various spheres of reality. This was a common practice for the Greek philosophers in a society which saw gods everywhere, and therefore could fit their ideas into a tolerably elastic system.<ref>C. M. Bowra (1957) ''The Greek experience''. World publishing Company. Cleveland and New York. p168,169.</ref>

Some scholars{{who|date=May 2022}} see a gap between the existing mythical and the new [[rationalism|rational]] way of thought which is the main characteristic of the [[Archaic Greece|archaic period]] (8th to 6th century BC) in the Greek [[city-state]]s.<ref>[[Herbert Ernest Cushman]] claims Anaximander has "the first European philosophical conception of god", ''A beginner's history of philosophy'', Volume 1 pg. 24</ref> This has given rise to the phrase "Greek miracle". But there may not have been such an abrupt break as initially appears. The basic elements of nature ([[Water (classical element)|water]], [[Air (classical element)|air]], [[Fire (classical element)|fire]], [[Earth (classical element)|earth]]) which the first Greek philosophers believed made up the universe in fact represent the primordial forces imagined in earlier ways of thinking. Their collision produced what the mythical tradition had called cosmic harmony. In the old cosmogonies&nbsp;– [[Hesiod]] (8th&nbsp;– 7th century&nbsp;BC) and [[Pherecydes of Syros|Pherecydes]] (6th century BC)&nbsp;– [[Zeus]] establishes his order in the world by destroying the powers which were threatening this harmony (the [[Titans (mythology)|Titans]]). Anaximander claimed that the cosmic order is not [[monarchic]] but [[geometric]], and that this causes the equilibrium of the Earth, which is lying in the centre of the universe. This is the projection on nature of a new political order and a new space organized around a centre which is the static point of the system in the society as in nature.<ref>C. Mosse (1984) ''La Grece archaique d'Homere a Eschyle''. Edition du Seuil. p 235</ref> In this space there is ''isonomy'' (equal rights) and all the forces are symmetrical and transferable. The decisions are now taken by the assembly of ''[[Wiktionary:demos|demos]]'' in the ''[[agora]]'' which is lying in the middle of the city.<ref>J. P. Vernart (1982) ''Les origins de la pensee grecque''. PUF Pariw. p 128, J. P. Vernart (1982) ''The origins of the Greek thought''. Cornell University Press.</ref>

The same ''rational'' way of thought led him to introduce the abstract ''[[Apeiron (cosmology)|apeiron]]'' (indefinite, infinite, boundless, unlimited<ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Da%29pei%2Frwn2 ἀπείρων], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref>) as an origin of the universe, a concept that is probably influenced by the original [[Chaos (mythology)|Chaos]] (gaping void, abyss, formless state) from which everything else appeared in the mythical [[Greece|Greek]] [[cosmogony]].<ref>''The Theogony of Hesiod'', Transl. H. G. Evelyn White, 736–740</ref> It also takes notice of the mutual changes between the four elements. Origin, then, must be something else unlimited in its source, that could create without experiencing decay, so that genesis would never stop.<ref>Aetios, I 3,3 [ [[Pseudo-Plutarch]]; DK 12 A 14.]; Aristotle, ''Phys''. Γ5,204b 23sq. [DK 12 A 16.]</ref>

=== Apeiron ===

{{main|Apeiron|Matter#Classical antiquity (c. 600 BCE–c. 322 BCE)}}{{See also|Classical element#Hellenistic philosophy}}

The ''Refutation'' attributed to [[Hippolytus of Rome]] (I, 5), and the later 6th century Byzantine philosopher [[Simplicius of Cilicia]], attribute to Anaximander the earliest use of the word ''apeiron'' ({{lang|grc|ἄπειρον}} "infinite" or "limitless") to designate the original principle. He was the first philosopher to employ, in a philosophical context, the term ''[[Arche|archē]]'' ({{lang|grc|ἀρχή}}), which until then had meant beginning or origin.

"That Anaximander called this something by the name of {{lang|grc|Φύσις}} is the natural interpretation of what [[Theophrastus|Theophrastos]] says; the current statement that the term {{lang|grc|ἀρχή}} was introduced by him appears to be due to a misunderstanding."<ref name="Burnet 1930 54">{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn/page/54 54]}}</ref>

And "Hippolytos, however, is not an independent authority, and the only question is what Theophrastos wrote."<ref>{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn_e8u1|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn_e8u1/page/54 54] footnote 2|isbn=9780713603378}}</ref>

For him, it became no longer a mere point in time, but a source that could perpetually give birth to whatever will be. The indefiniteness is spatial in early usages as in [[Homer]] (indefinite sea) and as in [[Xenophanes]] (6th century BC) who said that the Earth went down indefinitely (to ''apeiron'') i.e. beyond the imagination or concept of men.<ref>{{Cite book |last1=Kirk |first1=G. S. |last2=Raven |first2=J. E. |last3=Schofield |first3=M. |title=The Presocratic Philosophers|name-list-style=amp| date=2003| publisher=Cambridge University Press| url= https://books.google.com/books?id=kFpd86J8PLsC| isbn=978-0-521-27455-5| page=110}}</ref>

Burnet (1930) in ''Early Greek Philosophy'' says:

<blockquote>"Nearly all we know of Anaximander's system is derived in the last resort from Theophrastos, who certainly knew his book. He seems once at least to have quoted Anaximander's own words, and he criticised his style. Here are the remains of what he said of him in the First Book:</blockquote>

<blockquote><nowiki/>"Anaximander of Miletos, son of Praxiades, a fellow-citizen and associate of Thales, said that the material cause and first element of things was the Infinite, he being the first to introduce this name of the material cause. He says it is neither water nor any other of the so-called elements, but a substance different from them which is infinite" [apeiron, or {{lang|grc|ἄπειρον}}] "from which arise all the heavens and the worlds within them.—Phys, Op. fr. 2 (Dox. p. 476; R. P. 16)."<ref>{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn/page/52 52]}}</ref></blockquote>

Burnet's quote from the "First Book" is his translation of Theophrastos' ''Physic Opinion'' fragment 2 as it appears in p.&nbsp;476 of ''Historia Philosophiae Graecae'' (1898) by Ritter and Preller and section 16 of ''Doxographi Graeci'' (1879) by Diels.

By ascribing the "Infinite" with a "material cause", Theophrastos is following the Aristotelian tradition of "nearly always discussing the facts from the point of view of his own system".<ref>{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn_e8u1|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn_e8u1/page/31 31]–32|isbn=9780713603378}}</ref>

Aristotle writes (''[[Metaphysics (Aristotle)|Metaphysics]]'', I.III 3–4) that the [[Pre-Socratic philosophy|Pre-Socratics]] were searching for the element that constitutes all things. While each pre-Socratic philosopher gave a different answer as to the identity of this element ([[water (classical element)|water]] for Thales and [[air (classical element)|air]] for Anaximenes), Anaximander understood the beginning or first principle to be an endless, unlimited primordial mass (''apeiron''), subject to neither old age nor decay, that perpetually yielded fresh materials from which everything we perceive is derived.<ref>[[Pseudo-Plutarch]], ''The Doctrines of the Philosophers'' (I, 3).</ref> He proposed the theory of the ''apeiron'' in direct response to the earlier theory of his teacher, Thales, who had claimed that the primary substance was water. The notion of temporal infinity was familiar to the Greek mind from remote antiquity in the religious concept of immortality, and Anaximander's description was in terms appropriate to this conception. This ''archē'' is called "eternal and ageless". (Hippolytus (?), ''Refutation'', I,6,I;DK B2)<ref>{{Cite book |last=Guthrie |first=William Keith Chambers |title=A History of Greek Philosophy| date=2000| publisher=Cambridge University Press| url= https://books.google.com/books?id=ogUR3V9wbbIC| isbn=978-0-521-29420-1 |page=83}}</ref>

<blockquote>"''Aristotle puts things in his own way regardless of historical considerations, and it is difficult to see that it is more of an anachronism to call the Boundless " intermediate between the elements " than to say that it is " distinct from the elements." Indeed, if once we introduce the elements at all, the former description is the more adequate of the two. At any rate, if we refuse to understand these passages as referring to Anaximander, we shall have to say that Aristotle paid a great deal of attention to some one whose very name has been lost, and who not only agreed with some of Anaximander's views, but also used some of his most characteristic expressions. We may add that in one or two places Aristotle certainly seems to identify the " intermediate " with the something " distinct from " the elements''."<ref>{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn_e8u1|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn_e8u1/page/57 57]|isbn=9780713603378}}</ref></blockquote>

<blockquote>"It is certain that he [Anaximander] cannot have said anything about elements, which no one thought of before Empedokles, and no one could think of before Parmenides. The question has only been mentioned because it has given rise to a lengthy controversy, and because it throws light on the historical value of Aristotle's statements. From the point of view of his own system, these may be justified; but we shall have to remember in other cases that, when he seems to attribute an idea to some earlier thinker, we are not bound to take what he says in an historical sense."<ref>{{Cite book|title=Early Greek Philosophy|url=https://archive.org/details/earlygreekphilos0000burn|url-access=registration|last=Burnet|first=John|publisher=A. & C. Black, Ltd.|year=1930|location=Great Britain|pages=[https://archive.org/details/earlygreekphilos0000burn/page/56 56]–57}}</ref></blockquote>

For Anaximander, the [[Principle (chemistry)|principle]] of things, the constituent of all substances, is nothing determined and not an element such as water in Thales' view. Neither is it something halfway between air and water, or between air and fire, thicker than air and fire, or more subtle than water and earth.<ref>[[Aristotle]], ''[[On Generation and Corruption]]'' (II, 5)</ref> Anaximander argues that water cannot embrace all of the opposites found in nature – for example, water can only be wet, never dry – and therefore cannot be the one primary substance; nor could any of the other candidates. He postulated the ''apeiron'' as a substance that, although not directly perceptible to us, could explain the opposites he saw around him.

<blockquote>"If Thales had been right in saying that water was the fundamental reality, it would not be easy to see how anything else could ever have existed. One side of the opposition, the cold and moist, would have had its way unchecked, and the warm and dry would have been driven from the field long ago. We must, then, have something not itself one of the warring opposites, something more primitive, out of which they arise, and into which they once more pass away."<ref name="Burnet 1930 54"/></blockquote>

Anaximander explains how the [[Classical element|four elements]] of ancient physics ([[air (classical element)|air]], [[earth (classical element)|earth]], [[water (classical element)|water]] and [[fire (classical element)|fire]]) are formed, and how Earth and terrestrial beings are formed through their interactions. Unlike other Pre-Socratics, he never defines this principle precisely, and it has generally been understood (e.g., by Aristotle and by [[Augustine of Hippo|Saint Augustine]]) as a sort of primal [[Chaos (cosmogony)|chaos]]. According to him, the Universe originates in the separation of opposites in the primordial matter. It embraces the opposites of hot and cold, wet and dry, and directs the movement of things; an entire host of shapes and differences then grow that are found in "all the worlds" (for he believed there were many).<ref name="Chisholm1911"/>

<blockquote>"Anaximander taught, then, that there was an eternal. The indestructible something out of which everything arises, and into which everything returns; a boundless stock from which the waste of existence is continually made good, "elements.". That is only the natural development of the thought we have ascribed to Thales, and there can be no doubt that Anaximander at least formulated it distinctly. Indeed, we can still follow to some extent the reasoning which led him to do so. Thales had regarded water as the most likely thing to be that of which all others are forms; Anaximander appears to have asked how the primary substance could be one of these particular things. His argument seems to be preserved by Aristotle, who has the following passage in his discussion of the Infinite: ''"Further, there cannot be a single, simple body which is infinite, either, as some hold, one distinct from the elements, which they then derive from it, or without this qualification. For there are some who make this. (i.e. a body distinct from the elements). the infinite, and not air or water, in order that the other things may not be destroyed by their infinity. They are in opposition one to another. air is cold, water moist, and fire hot. and therefore, if any one of them were infinite, the rest would have ceased to be by this time. Accordingly they say that what is infinite is something other than the elements, and from it the elements arise.'⁠—Aristotle Physics. F, 5 204 b 22 (Ritter and Preller (1898) Historia Philosophiae Graecae, section 16 b)."''<ref>{{Cite book |title=Early Greek Philosophy |url=https://archive.org/details/earlygreekphilos0000burn |url-access=registration |last=Burnet |first=John |publisher=A. & C. Black |year=1930 |location=Great Britain |pages=[https://archive.org/details/earlygreekphilos0000burn/page/53 53]}}</ref></blockquote>

Anaximander maintains that all dying things are returning to the element from which they came (''apeiron''). The one surviving fragment of Anaximander's writing deals with this matter. Simplicius transmitted it as a quotation, which describes the balanced and mutual changes of the elements:<ref>[[Simplicius of Cilicia|Simplicius]], ''Comments on Aristotle's Physics'' (24, 13):

: "{{lang|grc|Ἀναξίμανδρος [...] λέγει δ' αὐτὴν μήτε ὕδωρ μήτε ἄλλο τι τῶν καλουμένων εἶναι στοιχείων, ἀλλ' ἑτέραν τινὰ φύσιν ἄπειρον, ἐξ ἧς ἅπαντας γίνεσθαι τοὺς οὐρανοὺς καὶ τοὺς ἐν αὐτοῖς κόσμους· ἐξ ὧν δὲ ἡ γένεσίς ἐστι τοῖς οὖσι, καὶ τὴν φθορὰν εἰς ταῦτα γίνεσθαι κατὰ τὸ χρεών· διδόναι γὰρ αὐτὰ δίκην καὶ τίσιν ἀλλήλοις τῆς ἀδικίας κατὰ τὴν τοῦ χρόνου τάξιν, ποιητικωτέροις οὕτως ὀνόμασιν αὐτὰ λέγων. δῆλον δὲ ὅτι τὴν εἰς ἄλληλα μεταβολὴν τῶν τεττάρων στοιχείων οὗτος θεασάμενος οὐκ ἠξίωσεν ἕν τι τούτων ὑποκείμενον ποιῆσαι, ἀλλά τι ἄλλο παρὰ ταῦτα· οὗτος δὲ οὐκ ἀλλοιουμένου τοῦ στοιχείου τὴν γένεσιν ποιεῖ, ἀλλ' ἀποκρινομένων τῶν ἐναντίων διὰ τῆς αἰδίου κινήσεως.}}"

In [[Ancient Greek]] quotes usually blend with surrounding text. Consequently, it is uncertain how much is Anaximander's text and what is by Simplicius.</ref><ref>{{cite book |last=Curd |first=Patricia |title=A Presocratics Reader: Selected Fragments and Testimonia |publisher=[[Hackett Publishing]] |year=1996 |page=12}}</ref>

<blockquote>
Whence things have their origin,<br/>
Thence also their destruction happens,<br/>
According to necessity;<br/>
For they give to each other justice and recompense<br/>
For their injustice<br/>
In conformity with the ordinance of Time.
</blockquote>

Simplicius mentions that Anaximander said all these "in poetic terms", meaning that he used the old mythical language. The goddess Justice ([[Dike (mythology)|Dike]]) keeps the cosmic order. This concept of returning to the element of origin was often revisited afterwards, notably by Aristotle,<ref>Aristotle, ''Metaphysics'', I, 3, 983 ''b'' 8–11; ''[[Physics (Aristotle)|Physics]]'', III, 5, 204 ''b'' 33–34</ref> and by the Greek [[Tragedy|tragedian]] [[Euripides]]: "what comes from earth must return to earth."<ref>Euripides''[[The Suppliants (Euripides)|Supplices]]'', v. 532</ref> [[Friedrich Nietzsche]], in his ''[[Philosophy in the Tragic Age of the Greeks]]'', stated that Anaximander viewed "... all coming-to-be as though it were an illegitimate emancipation from eternal being, a wrong for which destruction is the only penance."<ref>[[Friedrich Nietzsche]], ''[[Philosophy in the Tragic Age of the Greeks]]'' (1873) § 4.</ref> Physicist [[Max Born]], in commenting upon [[Werner Heisenberg]]'s arriving at the idea that the elementary particles of [[quantum mechanics]] are to be seen as different manifestations, different quantum states, of one and the same "primordial substance,"' proposed that this primordial substance be called ''apeiron''.<ref>{{cite book |chapter-url= https://books.google.com/books?id=Bmcpsgp-Ml4C&pg=PA546 | page= 546 |title=A Cultural History of Physics |last=Károly |first= Simonyi |author-link= Simonyi Károly |date= April 7, 2012 |chapter= 5.5.10 Back to the Apeiron? |publisher= CRC Press |isbn=9781568813295 <!-- print source, but for the fans: |access-date=July 9, 2013 -->}}</ref>

=== A free-floating Earth ===

Anaximander was the first to conceive a mechanical model of the world. In his model, the Earth floats very still in the centre of the infinite, not supported by anything. It remains "in the same place because of its indifference", a point of view that Aristotle considered ingenious, in ''[[On the Heavens]]''.<ref>Aristotle, ''On the Heavens'', ii, 13</ref> Its curious shape is that of a cylinder<ref>"A column of stone", [[Aëtius (theologian)|Aetius]] reports in ''De Fide'' (III, 7, 1), or "similar to a pillar-shaped stone", pseudo-Plutarch (III, 10).</ref> with a height one-third of its diameter. The flat top forms the inhabited world.

[[Carlo Rovelli]] suggests that Anaximander took the idea of the Earth's shape as a floating disk from [[Thales of Miletus|Thales]], who had imagined the Earth floating in water, the "immense ocean from which everything is born and upon which the Earth floats."{{sfn|Rovelli|2023|p=48}} Anaximander was then able to envisage the Earth at the centre of an infinite space, in which case it required no support as there was nowhere "down" to fall. In Rovelli's view, the shape – a cylinder or a sphere – is unimportant compared to the appreciation of a "finite body that floats free in space."{{sfn|Rovelli|2023|p=48}}

[[File:Floating Earth Thales Anaximander.svg|thumb|upright=1.75|center|Whereas [[Thales of Miletus|Thales]] thought the Earth floated in the great Ocean, Anaximander saw the Earth as floating in the infinite. Where Thales conceived of things falling down to Earth, and Earth being above the Ocean, Anaximander saw the Earth as the centre, and that things could fall from any direction. This has been thought a large conceptual advance in cosmology.{{sfn|Rovelli|2023|pp=48–52}}]]

Anaximander's realization that the Earth floats free without falling and does not need to be resting on something has been indicated by many as the first cosmological revolution and the starting point of scientific thinking.{{sfn|Rovelli|2023|pp=49–50}} [[Karl Popper]] calls this idea "one of the boldest, most revolutionary, and most portentous ideas in the whole history of human thinking."<ref>Karl Popper, "Conjectures and Refutations: The Growth of Scientific Knowledge" (New York: Routledge, 1998), p. 186.</ref> Such a model allowed the concept that [[Astronomical object|celestial bodies]] could pass under the Earth, opening the way to Greek astronomy. Rovelli suggests that seeing the stars circling the [[Pole star]], and both vanishing below the horizon on one side and reappearing above it on the other, would suggest to the astronomer that there was a void both above and below the Earth.{{sfn|Rovelli|2023|pp=50–52}}

[[File:Starry Spin-up.jpg|thumb|upright=1.75|center|The sight of stars circling the [[Pole star]] and vanishing and reappearing at the horizon could have suggested to Anaximander that the Earth was surrounded above and below by a void.{{sfn|Rovelli|2023|pp=50–52}}]]

=== Cosmology ===

[[File:Anaximander cosmology-en.svg|thumb|left|280px|Map of Anaximander's universe]]

Anaximander's bold use of non-[[Greek mythology|mythological]] explanatory hypotheses considerably distinguishes him from previous cosmology writers such as [[Hesiod]].{{sfn|Rovelli|2023|pp=42–43}} It indicates a pre-Socratic effort to demystify physical processes. His major contribution to history was writing the oldest prose document about the Universe and the origins of life; for this he is often called the "Father of [[Cosmology]]" and founder of astronomy. However, [[pseudo-Plutarch]] states that he still viewed celestial bodies as deities.<ref>Pseudo-Plutarch, ''Doctrines of the Philosophers'', i. 7</ref> He placed the celestial bodies in the wrong order. He thought that the stars were nearest to the Earth, then the Moon, and the Sun farthest away. His scheme is compatible with the [[Indo-Iranians|Indo-Iranian]] philosophical traditions contained in the Iranian [[Avesta]] and the Indian [[Upanishads]].<ref>{{cite journal |last1=Marcovich |first1=Miroslav |date=June 1975 |title=Reviewed Work: Early Greek Philosophy and the Orient by M. L. West |journal=Gnomon |volume=47 |issue=4 |pages=321–328}}</ref>

[[File:Persectives of Anaximander's universe.png|thumb|right|350px|Illustration of Anaximander's models of the universe. On the left, daytime in summer; on the right, nighttime in winter. Note the sphere represents the combined rings of all of the stars about the very small inner cylinder which represents the Earth.]]

At the origin, after the separation of hot and cold, a ball of flame appeared that surrounded Earth like bark on a tree. This ball broke apart to form the rest of the Universe. It resembled a system of hollow concentric wheels, filled with fire, with the rims pierced by holes like those of a flute. Consequently, the Sun was the fire that one could see through a hole the same size as the Earth on the farthest wheel, and an eclipse corresponded with the [[Occultation|occlusion]] of that hole. The diameter of the solar wheel was twenty-seven times that of the Earth (or twenty-eight, depending on the sources)<ref>In ''Refutation'', it is reported that the circle of the Sun is twenty-seven times bigger than the Moon.</ref> and the lunar wheel, whose fire was less intense, eighteen (or nineteen) times. Its hole could change shape, thus explaining [[lunar phase]]s. The stars and the planets, located closer,<ref>Aetius, ''De Fide'' (II, 15, 6)</ref> followed the same model.<ref>Most of Anaximander's model of the Universe comes from pseudo-Plutarch (II, 20–28):

: "[The Sun] is a circle twenty-eight times as big as the Earth, with the outline similar to that of a fire-filled chariot wheel, on which appears a mouth in certain places and through which it exposes its fire, as through the hole on a flute. [...] the Sun is equal to the Earth, but the circle on which it breathes and on which it's borne is twenty-seven times as big as the whole earth. [...] [The eclipse] is when the mouth from which comes the fire heat is closed. [...] [The Moon] is a circle nineteen times as big as the whole earth, all filled with fire, like that of the Sun".</ref>

Anaximander was the first astronomer to consider the Sun as a huge mass, and consequently, to realize how far from Earth it might be, and the first to present a system where the celestial bodies turned at different distances. Furthermore, according to Diogenes Laertius (II, 2), he built a [[celestial spheres|celestial sphere]].{{failed verification|date=October 2023}} This invention undoubtedly made him the first to realize the [[Axial tilt|obliquity]] of the [[Zodiac]] as the Roman philosopher [[Pliny the Elder]] reports in ''[[Natural History (Pliny)|Natural History]]'' (II, 8). It is a little early to use the term [[ecliptic]], but his knowledge and work on astronomy confirm that he must have observed the inclination of the celestial sphere in relation to the plane of the Earth to explain the seasons. The [[doxography|doxographer]] and theologian Aetius attributes to Pythagoras the exact measurement of the obliquity.

=== Multiple worlds ===

According to Simplicius, Anaximander already speculated on the [[Cosmic pluralism|plurality of worlds]], similar to [[atomism|atomists]] [[Leucippus]] and [[Democritus]], and later philosopher [[Epicurus]]. These thinkers supposed that worlds appeared and disappeared for a while, and that some were born when others perished. They claimed that this movement was eternal, "for without movement, there can be no generation, no destruction".<ref>Simplicius, ''Commentary on Aristotle's Physics'', 1121, 5–9</ref>

In addition to Simplicius, Hippolytus<ref>Hippolytus (?), ''Refutation'' I, 6</ref> reports Anaximander's claim that from the infinite comes the principle of beings, which themselves come from the heavens and the worlds (several doxographers use the plural when this philosopher is referring to the worlds within,<ref>Notably pseudo-Plutarch (III, 2) and Aetius, (I, 3, 3; I, 7, 12; II, 1, 3; II, 1, 8).</ref> which are often infinite in quantity). [[Cicero]] writes that he attributes different gods to the countless worlds.<ref>''On the Nature of the Gods'' (I, 10, 25):

: ''"Anaximandri autem opinio est nativos esse deos longis intervallis orientis occidentisque, eosque innumerabiles esse mundos."''
: "For Anaximander, gods were born, but the time is long between their birth and their death; and the worlds are countless."</ref>

This theory places Anaximander close to the Atomists and the [[Epicureanism|Epicureans]] who, more than a century later, also claimed that an infinity of worlds appeared and disappeared. In the [[Timeline of Western philosophers#Classical philosophers|timeline of the Greek history of thought]], some thinkers conceptualized a single world (Plato, Aristotle, [[Anaxagoras]] and [[Archelaus (philosopher)|Archelaus]]), while others instead speculated on the existence of a series of worlds, continuous or non-continuous ([[Anaximenes of Miletus|Anaximenes]], [[Heraclitus]], [[Empedocles]] and [[Diogenes Apolloniates|Diogenes]]).

=== Meteorological phenomena ===

Anaximander attributed some phenomena, such as thunder and lightning, to the intervention of elements, rather than to divine causes.<ref>Pseudo-Plutarch (III, 3):

: "Anaximander claims that all this is done by the wind, for when it happens to be enclosed in a thick cloud, then by its subtlety and lightness, the rupture produces the sound; and the scattering, because of the darkness of the cloud, creates the light."</ref> In his system, thunder results from the shock of clouds hitting each other; the loudness of the sound is proportionate with that of the shock. Thunder without lightning is the result of the wind being too weak to emit any flame, but strong enough to produce a sound. A flash of lightning without thunder is a jolt of the air that disperses and falls, allowing a less active fire to break free. Thunderbolts are the result of a thicker and more violent air flow.<ref>According to [[Seneca the Younger|Seneca]], ''Naturales quaestiones'' (II, 18).</ref>

He saw the sea as a remnant of the mass of humidity that once surrounded Earth.<ref>Pseudo-Plutarch (III, 16)</ref> A part of that mass evaporated under the Sun's action, thus causing the winds and even the rotation of the celestial bodies, which he believed were attracted to places where water is more abundant.<ref>It is then very likely that by observing the Moon and the tides, Anaximander thought the latter were the cause, and not the effect of the satellite's movement.</ref> He explained rain as a product of the humidity pumped up from Earth by the sun.<ref name="Refutation" /> For him, the Earth was slowly drying up and water only remained in the deepest regions, which someday would go dry as well. According to Aristotle's ''[[Meteorology (Aristotle)|Meteorology]]'' (II, 3), Democritus also shared this opinion.

=== Origin of mankind ===

Anaximander speculated about the beginnings and [[Evolution|origin]] of animal life, and that humans came from other animals in waters.<ref name=":0">{{Cite web |url=https://www.iep.utm.edu/presocra/#SH2b |title=Presocratics |last=Graham |first=Jacob |website=Internet Encyclopedia of Philosophy}}</ref><ref>Anaximander, frag. A30</ref> According to his [[History of evolutionary thought|evolutionary theory]], animals sprang out of the sea long ago, born trapped in a spiny bark, but as they got older, the bark would dry up and animals would be able to break it.<ref>Aetius, Opinions, V, XIX, 4.</ref> The 3rd century Roman writer [[Censorinus]] reports:

{{blockquote|text=Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after these animals burst open, could men and women come out, now able to feed themselves.<ref>Censorinus, ''De Die Natali'', IV, 7</ref>|sign=|source=}}

Anaximander put forward the idea that humans had to spend part of this transition inside the mouths of big fish to protect themselves from the Earth's climate until they could come out in open air and lose their scales.<ref>[[Plutarch]] also mentions Anaximander's theory that humans were born inside fish, feeding like sharks, and that when they could defend themselves, they were thrown ashore to live on dry land.</ref> He thought that, considering humans' extended infancy, we could not have survived in the primeval world in the same manner we do presently.