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Philolaus (ca. 470 B.C.E. – ca. 385 B.C.E., Greek: Φιλόλαος) was a Greek Presocratic philosopher and one of the three prominent Pythagoreans. He was born approximately one hundred years after Pythagoras himself and fifty years before Archytas, and though characterized as a Pythagorean, he propounded several original theories of his own. He was the first Pythagorean to write and disseminate a philosophical treatise, and is credited with having written one book, of which eleven genuine fragments are extant. Aristotle appears to have drawn his account of Pythagoreanism from this work, though he never mentions it or Philolaus by name.

Philolaus was the first to declare that the Earth was not the stationary center of the cosmos, but moved around a central fire along with the fixed stars, the five planets, the Sun, Moon, and a mysterious “counter-earth.” Philolaus argued that the cosmos and everything in it was made up of two basic types of things, "limited things" and "unlimited things," subject to a “fitting together,” or “harmonia,” which accounted for the formation of the cosmos and its phenomena, and could be described mathematically. Philolaus followed Pythagorean number theory, and held that the elementary nature of bodies depended on their geometric form. His ideas about the nature of the Earth's place in the cosmos influenced Aristarchus of Samos. Nicolaus Copernicus mentioned in De revolutionibus that Philolaus already knew about the Earth's revolution around a central fire.

Life and Chronology

As is the case with most other Presocratic thinkers, "any chronology constructed for his life is a fabric of the loosest possible weave." [1] That should not diminish the importance of establishing such a chronology, which helps scholars see his relationship to other Pre-Socratics. A passage out of Plato's Phaedo reveals his influence on two of the characters within the dialogue:

"What, Cebes? Have you and Simmias not heard about such things in your association with Philolaus?"

"Nothing definite, at least, Socrates… Why ever then do they deny that it is unlawful to kill oneself Socrates? For, to answer the question that you were just now asking, I already heard from Philolaus, when he was spending time with us, and before that from some others as well, that it was not right to do this."

From this passage it is clear that Philolaus had spent time in Thebes and was heard by Simmias and Cebes around the time the Phaedo takes place, in 399 B.C.E.. The dates of his birth and death are culled from his known association with other Pre-Socratics. Plutarch relates that as a young man Philolaus was one of two to escape the burning of the Pythagorean meeting place in Metapontum in 454 B.C.E. (On the Sign of Socrates 583a) but earlier versions of this story do not mention Philolaus (Aristoxenus in Iamblichus, VP 249-50) so that it is not certain that he was involved in the incident [2]. Besides this chronological outline the details of Philolaus’ life are unknown to us.

Philolaus and Eurytus are two of the Pythagoreans that Plato is mentioned as having met on his fist visit to Italy. The pupils of Philolaus and Eurytus were Xenophilus of Chalcis, Thrace; Phanto of Phlius; Echecrates of Phlius; Diocles of Phlius; and Polymnastus of Phlius. Philolaus was a contemporary of Socrates and Democritus, but senior to them, and was probably somewhat junior to Empedocles, and a contemporary of Zeno of Elea, Melissus of Samos and Thucydides, so that his birth may be placed at about 480 B.C.E..

Philolaus was born in southern Italy, in either Croton, Tarentum, or Heraclea, according to the doxography of Diogenes Laertius. He was said to have been intimate with Democritus, and was probably one of his teachers, which would make him somewhat older than Democritus (D. L. IX 38), who was born ca. 460.

It is even less clear when Philolaus died, but one report suggests that he may still have been alive in the early 380s, when Plato first visited southern Italy (D.L. III 6). If he lived from ca. 470 to ca. 385, Philolaus is an approximate contemporary of Socrates. According to some accounts, Philolaus, obliged to flee following attacks on the Pythagoreans in other southern Italian cities ca. 450 B.C.E., took refuge first in Lucania and then at Thebes, where he had as pupils Simmias and Cebes (Crito), all three of whom were subsequently present at the death of Socrates in 399 B.C.E.. Before this, Philolaus had returned to Italy, where he was the teacher of Archytas (428–347 B.C.E.) (Cicero, de Orat. III 34.139). Philolaus was perhaps also connected with the Pythagorean exiles at Phlius mentioned in Plato's Phaedo. Diogenes Laertes laments that, though innocent, Philolaus was killed because of suspicions that he was involved in treason.

Thought and Works


Philolaus was one of the three most prominent figures in the Pythagorean tradition, born a hundred years after Pythagoras himself and fifty years before Archytas. Philolaus was the first Pythagorean to write and disseminate a philosophical treatise; he published a book, of which remain only extant fragments of other philosophers and doxographers.

Philolaus spoke and wrote in a Greek Doric dialect. There are two traditions regarding Philolaus’ publication of books (Burkert 1972a, 223-7; Huffman 1993, 12-15). The first, found in Diogenes Laertius (VIII 85), but going back to Hermippus (third B.C.E.) and Timon (DK 44 A8; 320-230 B.C.E.), credits Philolaus with having published one book, which is given the title “On Nature.

He wrote one book, which Hermippus reports, on the authority of some unknown writer, that Plato the philosopher purchased when he was in Sicily (having come thither to the court of Dionysius), of the relations of Philolaus, for forty Alexandrian minae of silver; and that from this book he copied his Timaeus. But others say that Plato received it as a present, after having obtained his liberty for a young man, one of the disciples of Philolaus, who had been arrested by Dionysius. Demetrius, in his treatise on people of the same name, says that he was the first of the Pythagoreans who wrote a treatise on Natural Philosophy; and it begins thus: "But nature in the world has been composed of bodies infinite and finite, and so is the whole world and all that is in it." (Diogenes Laertius VIII 85, IV)

According to a second tradition, also documented by Diogenes Laertius, Plato bought three books from Philolaus (Diogenes Laertius III 9; VIII 15 and 84). This story of Plato's purchase of books from Philolaus was probably invented to authenticate the three forged treatises of Pythagoras; it is implied that they were not written by Philolaus.

Although some of the approximately twenty fragments attributed to Philolaus have been identified as forgeries from later works written under his name, eleven core fragments are considered to be authentic.

Aristotle stated that fifth-century Pythagoreanism, which he identified as being contemporary with the atomists, had some influence on Plato but made no distinction between the intelligible and sensible world (1972a, 28-52). He described a system of cosmology very similar to that presented in the fragments of Philolaus’ writings, but never attributed it directly to Philolaus.

Speusipus, the Plato's successor at the Academy summarized Philolaus's work. Though he is described as a Pythagorean, Philolaus developed highly original theories of his own.


Philolaus was the first to propound the doctrine that the Earth was not the stationary center of the cosmos, but moved around a central fire; some attribute this doctrine to Pythagoras, but there is no evidence in support of either Pythagoras or the younger Hicetas (ca. 400 B.C.E. - ca. 335 B.C.E.) of Syracuse.

Philolaus supposed that the fixed stars, the five planets, the Sun, Moon and Earth, all revolved around the central fire, but as these made up only nine bodies, in accordance with his number theory he conceived a tenth, which he called “counter-earth.” The central holy fire was not the Sun, but some mysterious thing between the Earth and counter-earth. He named it "estia," the hearth of the universe, the house of Zeus, and the mother of the gods, after the goddess of fire and hearth Hestia. He kept an idea of the Earth's rotation around its axis, claiming that the earth always turned away from the central fire as it revolved around it.

Passages in Aristotle's Metaphysics referring to Pythagoraean ideas gave rise to a popular misconception that Philolaus supposed that a sphere of the fixed stars, the five planets, the Sun, Moon and Earth, and the Counter-Earth all moved round his Central Fire. In reality, Philolaus' ideas predated the idea of spheres by hundreds of years, and the Counter-Earth was conceived to explain his revolutionary ideas about the lack of up or down in space to the Pythagorean community. He never recognized the fixed stars as any kind of sphere or object.[3]

Philolaus supposed the Sun to be a disk of glass which reflects the light of the universe. He made the lunar month consist of 29½ days, the lunar year of 354, and the solar year of 365½ days.

His ideas about the nature of the Earth's place in the cosmos influenced Aristarchus of Samos. Nicolaus Copernicus mentions in De revolutionibus that Philolaus already knew about the Earth's revolution around a central fire.

Pythagorean number theory

Philolaus argued that the cosmos and everything in it was made up of two basic types of things, "limited things" and "unlimited things." "Unlimited things" were undefined by any structure or quantity; and include the material elements such as earth, air, fire and water, but also continua such as space and time. "Limited things" included shapes and other structural principles which imposed structure and order on the unlimiteds. Limited and unlimited things were subject to a “fitting together” or “harmonia,” which accounted for the formation of the cosmos and its phenomena, and could be described mathematically. Philolaus' primary example of such a “harmonia” of limited and unlimited things was a musical scale, in which the continuum of sound is limited according to whole number ratios, so that the octave, fifth, and fourth are defined by the ratios 2 : 1, 4 : 3 and 3 : 2, respectively.

Since the whole world was structured according to number, our knowledge of the world was limited by the extent to which these numbers were understood. Philolaus followed Pythagorean number theory, dwelling particularly on the properties inherent in the decad, the sum of the first four numbers, consequently the fourth triangular number, the tetractys, which he called great, all-powerful, and all-producing. Philolaus held that the elementary nature of bodies depends on their form, and assigned the tetrahedron to fire, the octahedron to air, the icosahedron to water, and the cube to earth; the dodecahedron he assigned to a fifth element, aether, or, as some think, to the universe. This theory indicated considerable knowledge of geometry.


Following Parmenides' philosophy, Philolaus probably regarded the soul as a "mixture and harmony" of the bodily parts. He assumed a substantial soul, whose existence in the body is an exile. Philolaus recognized four psychic faculties; intellect (associated with the head), life and sensation (associated with the heart), nutrition and growth (associated with the navel), and generation and the sowing of seed (associated with the genitals). He distinguished between intellect (nous) which was limited to human beings, and perception, which was an attribute possessed by both humans and animals.


  1. Carl Huffman. Philolaus of Croton Pythagorean and Presocratic: A Commentary on the Fragments and Testimonia With Interpretive Essays. (New York: Cambridge University Press, 1993), 1–16.
  2. (Ibid., 2-3)
  3. George Bosworth Burch, The Counter-Earth. Osirus, vol. 11. (Saint Catherines Press, 1954), 267-294

ISBN links support NWE through referral fees

  • Barnes, Jonathan. 1979. The Presocratic philosophers. London: Routledge and Paul. ISBN 0710088604
  • Diogenes Laertius, and Robert Drew Hicks. 1925. Lives of eminent philosophers. London: W. Heinemann.
  • Huffman, Carl A., and Philolaus. 1993. Philolaus of Croton: Pythagorean and presocratic : a commentary on the fragments and testimonia with interpretive essays. Cambridge [England]: Cambridge University Press. ISBN 052141525X
  • Iamblichus, John M. Dillon, and Jackson P. Hershbell. 1991. On the Pythagorean way of life. Atlanta, Ga: Scholars Press. ISBN 1555405223
  • Kahn, Charles H. 2001. Pythagoras and the Pythagoreans: a brief history. Indianapolis, IN: Hackett Pub. ISBN 0872205754
  • This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.

External links

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