Avicenna

209

Avicenna : biography

980 – 1037

Other contributions

Astronomy and astrology

The practice of judicial astrology was refuted by Avicenna. His reasons were due to the methods used by astrologers in judicial astrology being conjectural rather than empirical and also due to the principles of this type of astrology conflicting with orthodox Islam. He also cited passages from the Qur’an in order to justify his refutation of astrology on both scientific and religious grounds.George Saliba (1994), A History of Arabic Astronomy: Planetary Theories During the Golden Age of Islam, p. 60, 67-69. New York University Press, ISBN 0-8147-8023-7. However, Avicenna’s refutation of astrology (in the treatise titled Resāla fī ebṭāl aḥkām al-nojūm) concerned only the judicial application of astrology rather than the philosophical principles of the subject and its natural influence. He stated that it was true that each planet had some influence on the earth, but his argument was the difficulty of astrologers being able to determine the exact effect of it. In essence, Avicenna did not refute astrology, but denied man’s limited capacity to be able to know the precise effects of the stars on the sublunar matter. With that, he did not refute the essential dogma of astrology, but only refuted our ability to fully understand it.George Saliba, Avicenna: ‘viii. Mathematics and Physical Sciences’. Encyclopaedia Iranica, Online Edition, 2011, available at http://www.iranicaonline.org/articles/avicenna-viii

In astronomy, he criticized Aristotle’s view of the stars receiving their light from the Sun. Ibn Sīnā stated that the stars are self-luminous, and believed that the planets are also self-luminous. He claimed to have observed the transit of Venus across the Sun on May 24, 1032. However, modern scholars have questioned whether he could have observed the transit from his location at that time. He used his transit observation to demonstrate that Venus was, at least sometimes, below the Sun in the Ptolemaic cosmology.

Soon after, he wrote the Compendium of the Almagest, a commentary on Ptolemy’s Almagest. Avicenna concluded that Venus is closer to the Earth than the Sun. In 1070, Abu Ubayd al-Juzjani, a pupil of Ibn Sīnā, claimed that his teacher Ibn Sīnā had solved the equant problem in the Ptolemaic model.A. I. Sabra (1998). "Configuring the Universe: Aporetic, Problem Solving, and Kinematic Modeling as Themes of Arabic Astronomy", Perspectives on Science 6 (3), p. 288–330 [305-306].

Chemistry

Ibn Sīnā used distillation to produce essential oils such as rose essence, forming the foundation of what later became aromatherapy.Marlene Ericksen (2000). Healing with Aromatherapy, p. 9. McGraw-Hill Professional. ISBN 0-658-00382-8. Four of his works on alchemy were translated into Latin as:Georges C. Anawati (1996), "Arabic alchemy", in Roshdi Rashed, ed., Encyclopedia of the History of Arabic Science, Vol. 3, p. 853–885 [875]. Routledge, London and New York.

  • Liber Aboali Abincine de Anima in arte Alchemiae
  • Declaratio Lapis physici Avicennae filio sui Aboali
  • Avicennae de congelatione et conglutinatione lapidum
  • Avicennae ad Hasan Regem epistola de Re recta

In one of these works, Ibn Sīnā discredited the theory of the transmutation of substances commonly believed by alchemists:

Among his works on alchemy, Liber Aboali Abincine de Anima in arte Alchemiae was the most influential, having influenced later medieval chemists and alchemists such as Vincent of Beauvais.

In another work, translated into Latin as De congelatione et conglutinatione lapidum, Ibn Sina proposed a four-part classification of inorganic bodies, which was a significant improvement over the two-part classification of Aristotle (into orycta and metals) and three-part classification of Galen (into terrae, lapides and metals). The four parts of Ibn Sina’s classification were: lapides, sulfur, salts and metals.