On the Heavens

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Page one of Aristotle's On the Heavens, from an edition published in 1837 Aristoteles De Caelo page 1.png
Page one of Aristotle's On the Heavens, from an edition published in 1837

On the Heavens (Greek: Περὶ οὐρανοῦ; Latin: De Caelo or De Caelo et Mundo) is Aristotle's chief cosmological treatise: written in 350 BC it contains his astronomical theory and his ideas on the concrete workings of the terrestrial world. It should not be confused with the spurious work On the Universe (De mundo, also known as On the Cosmos).

Contents

According to Aristotle in On the Heavens, the heavenly bodies are the most perfect realities, (or "substances"), whose motions are ruled by principles other than those of bodies in the sublunary sphere. The latter are composed of one or all of the four classical elements (earth, water, air, fire) and are perishable; but the matter of which the heavens are made is imperishable aether, so they are not subject to generation and corruption. Hence their motions are eternal and perfect, and the perfect motion is the circular one, which, unlike the earthly up-and down-ward locomotions, can last eternally selfsame - an early predecessor to Newton's First Law of Motion. Aristotle theorized that aether did not exist anywhere on Earth, but that it was an element exclusive to the heavens. As substances, celestial bodies have matter (aether) and form (a given period of uniform rotation). Sometimes Aristotle seems to regard them as living beings with a rational soul as their form [1] (see also Metaphysics , bk. XII).


Aristotle proposed a geocentric model of the universe in On the Heavens. The Earth is the center of motion of the universe, with circular motion being perfect because Earth was at the center of it. There can only be one center of the universe, and as a result there are no other inhabited worlds within it besides Earth. As such the Earth is unique and alone in this regard. Aristotle theorized that beyond the sublunary sphere and the heavens is an external spiritual space that mankind cannot fathom directly. [2] This work is significant as one of the defining pillars of the Aristotelian worldview, a school of philosophy that dominated intellectual thinking for almost two millennia. Similarly, this work and others by Aristotle were important seminal works by which much of scholasticism was derived.

Historical connections

Aristotelian philosophy and cosmology was influential in the Islamic world, where his ideas were taken up by the Falsafa school of philosophy throughout the later half of the first millennia AD. Of these, philosophers Averroes and Avicenna are especially notable. Averroes in particular wrote extensively about On The Heavens, trying for some time to reconcile the various themes of Aristotelian philosophy, such as natural movement of the elements and the concept of planetary spheres centered on the Earth, with the mathematics of Ptolemy. [3] These ideas would remain central to philosophical thought in the Islamic world well into the pre-modern period, and its influences can be found in both the theological and mystical tradition, including in the writings of al-Ghazali and Fakhr al-Din al-Razi.

Thomas Aquinas and Averroes St. Thomas Aquinas Confounding Averroes.jpg
Thomas Aquinas and Averroes

European philosophers had a similarly complex relationship with De Caelo, attempting to reconcile church doctrine with the mathematics of Ptolemy and the structure of Aristotle. A particularly cogent example of this is in the work of Thomas Aquinas, theologian, philosopher and writer of the 13th century. Known today as St. Thomas of the Catholic Church, Aquinas worked to synthesize Aristotle's cosmology as presented in De Caelo with Christian doctrine, an endeavor that led him to reclassify Aristotle's unmoved movers as angels and attributing the 'first cause' of motion in the celestial spheres to them. [4] Otherwise, Aquinas accepted Aristotle's explanation of the physical world, including his cosmology and physics.

The 14th century French philosopher Nicole Oresme translated and commentated on De Caelo in his role as adviser to King Charles V of France, on two separate occasions, once early on in life, and again near the end of it. These versions were a traditional Latin transcription and a more comprehensive French version that synthesized his views on cosmological philosophy in its entirety, Questiones Super de Celo and Livre du ciel et du monde respectively. "Livre du ciel et du monde" was written at the command of King Charles V, though for what purpose remains of some debate. Some speculate that, having already had Oresme translate Aristotelian works on ethics and politics in the hope of educating his courtiers, doing the same with De Caelo may be of some value to the king. [5]

Translations

(In reverse chronological order)

See also

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Dynamics of the celestial spheres

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The eternity of the world is the question of whether the world has a beginning in time or has existed from eternity. It was a concern for both ancient philosophers and the medieval theologians and medieval philosophers of the 13th century. The problem became a focus of a dispute in the 13th century, when some of the works of Aristotle, who believed in the eternity of the world, were rediscovered in the Latin West. This view conflicted with the view of the Catholic Church that the world had a beginning in time. The Aristotelian view was prohibited in the Condemnations of 1210–1277.

Jacques du Chevreul (1595-1649). Jacques du Chevreul was born in Coutances, France and died in Paris, France. Du Chevreul grew up in an educated household and was the son of a magistrate. In 1616, he received a Master of Arts for studying humanities and philosophy at the University of Paris. Du Chevreul continued education at a higher level and received a Bachelor of Divinity for theology in 1619. He did not start teaching until 1620 where he remained associated with College Harcourt and University of Paris, up until two years before his death when he taught philosophy at the College Royal. Throughout his lifetime Jacques du Chevreul held various teaching and administrative positions including principal and rector. Little is known about his later life. Although he studied subjects such as philosophy, logic, ethics, metaphysics, and physics, he published his two popular books on mathematics. Arithmetica (1622) and Sphaera were both published in Paris, France. Sphaera, du Chevreul's most popular book was about his view of the world and the universe. He used references from the Bible, Aristotle, and Plato to reject the Copernican model and instead created his own eccentric-epicycle geocentric model of the universe. Du Chevreul believed that the earth was the center of the universe, but that the major planets Venus and Mercury orbited around the sun. He theorized that there were wandering and fixed stars in the heavens and there were a total of thirteen planets in his model. The heavens were in the order of the Moon, the Sun, Mars, Jupiter surrounded by four Medicean stars, Saturn with two satellites, and above all these levels resided God. Du Chevreul's cosmic scheme is a highly original attempt to resist Copernicanism and accommodate Galieleo's telescopic discoveries in an Aristotelian cosmos.

References

  1. Alan C. Bowen, Christian Wildberg, New perspectives on Aristotle's De caelo (Brill, 2009)
  2. "Aristotle's On the Heavens". World History Encyclopedia. Retrieved 2021-04-08.
  3. Gerhard Endress (1995). Averroes' De Caelo Ibn Rushd's Cosmology in his Commentaries on Aristotle's On the Heavens. Arabic Sciences and Philosophy, 5, pp 9-49. doi:10.1017/S0957423900001934.
  4. McInerny, Ralph & O'Callaghan, John. "Saint Thomas Aquinas". The Stanford Encyclopedia of Philosophy (Winter 2010 Edition), Edward N. Zalta (Ed.).
  5. Grant, E. (n.d). Nicole Oresme, Aristotle's 'On the heavens', and the court of Charles V. Texts And Contexts In Ancient And Medieval Science : Studies On The Occasion Of John E, 187-207.

Further reading