Science started in the shadow of prison bars. Anaxagoras, who was born on the western shore of Asia Minor about the year 500 before the present era, taught “the moon has a light which is not its own, but comes from the sun.” From this it followed: “The sun is eclipsed at the new moon through the interposition of the moon.” (1)

“He was the first to set out distinctly the facts about the eclipses and illuminations,” wrote Hippolytus, a father of the Church, in his Refutation of All Heresies.

In the first century of the present era Plutarch gave this account:

Anaxagoras was the first to put in writing, most clearly and most courageously of all men, the explanation of the moon’s illumination and darkness. . . . His account was not common property, but was [still] a secret, current among only a few . . . For in those days they refused to tolerate the physicists and stargazers, as they were called, who presumed to fritter away the deity into unreasoning causes, blind forces, and necessary properties. Thus Protagoras was exiled, and Anaxagoras was imprisoned and with difficulty saved by Pericles.(2)

Anaxagoras was accused of impiety and sentenced for holding that the sun is a red-hot stone and the moon is of earthy nature. This was in disagreement with the view that these luminaries were deities. He taught: “The sun, the moon, and all the stars are stones of fire, which are carried round by the revolution of the aether.” (3)

Anaxagoras was put in prison and was marked for death, but Pericles barely succeeded to release him from the death house and set him free.(4) According to another account he was fined the heavy fine of five talents of silver and banished.(5) Possibly, the fine and expatriation were imposed upon him in lieu of capital punishment, by Pericles’ endeavor.

According to Theophrastus, Anaxagoras held that the moon was sometimes eclipsed by the interposition of other bodies (besides the earth) traveling below the moon.(6) Modern science does not know of such occultations of the moon and therefore denies such an explanation. Only large swarms of meteorites or comets, if interspersed between the earth and the moon, could cause the phenomenon.

Anaxagoras taught also that the terrestrial axis changed its direction in the past.(7) But if to give credence to Hippolytus, he thought that “the earth is flat in form.” (8) However, he believed that there are many earths like ours. According to a fragment of his,

Men were formed and other animals which have life; the men too have inhabited cities and cultivated fields as we do; they have also a sun and a moon and the rest (of the stars) as we have, and their earth produces for them many things of various kinds.(9)

In this there was already an initial departure from the belief in the uniqueness of the earth and its central position in the universe.


  1. Hippolytus, Refutatio Omnium Haeresium, I. 8. 6.

  2. Plutarch, De Placitis Philosophorum, “Anaxagoras.”

  3. Diogenes Laertius, Lives of the Philosophers II. 8.

  4. Ibid., II. 13.

  5. Ibid., II. 12.

  6. Theophrastus

  7. Diogenes Laertius, II. 9.

  8. Hippolytus, Refutatio Omnium Haeresium, I. 8. 3.

  9. Fragment 4 (H. Diels ed., Die Fragmente der Vorsokratiker [Berlin, 1952] II. 59).