# John Playfair

John Playfair FRSE, FRS (10 March 1748 – 20 July 1819) was a Church of Scotland minister, remembered as a scientist and mathematician, and a professor of natural philosophy at the University of Edinburgh. He is most famous for his book Illustrations of the Huttonian Theory of the Earth (1802), which summarised the work of James Hutton. It was through this book that Hutton's principle of uniformitarianism, later taken up by Charles Lyell, first reached a wide audience. Playfair's textbook Elements of Geometry made a brief expression of Euclid's parallel postulate known now as Playfair's axiom.

## Quotes

* “Aldebaran was therefore 40’ before the point of the vernal equinox, according to the Indian astronomy, in the year 3102 before Christ. (…) [Modern astronomy] gives the longitude of that star 13’ from the vernal equinox, at the time of the Calyougham, agreeing, within 53’, with the determination of the Indian astronomy. This agreement is the more remarkable, that the Brahmins, by their own rules for computing the motion of the fixed stars, could not have assigned this place to Aldebaran for the beginning of Calyougham, had they calculated it from a modern observation. For as they make the motion of the fixed stars too great by more than 3” annually, if they had calculated backward from 1491, they would have placed the fixed stars less advanced by 40 or 50, at their ancient epoch, than they have actually done.”
** John Playfair cited in Dharampal: Indian Science and Technology, p.87. , quoted in Elst, Koenraad (1999). Update on the Aryan invasion debate New Delhi: Aditya Prakashan.
* The observations on which the astronomy of India is founded, were made more than three thousand years before the Christian era. (…) Two other elements of this astronomy, the equation of the sun’s centre and the obliquity of the ecliptic (…) seem to point to a period still more remote, and to fix the origin of this astronomy 1000 or 1200 years earlier, that is, 4300 years before the Christian era.
** Playfair in Dharampal: Indian Science and Technology, p-118. , quoted in Elst, Koenraad (1999). Update on the Aryan invasion debate New Delhi: Aditya Prakashan.
* That observations made in India, when all Europe was barbarous or uninhabited, and investigations into the most subtle effects of gravitation made in Europe, near five thousand years afterwards, should thus come in mutual support of one another, is perhaps the most striking example of the progress and vicissitudes of science, which the history of mankind has yet exhibited. (179 0:160)
** Trautmann, Thomas R. (2008). Aryans and British India. 87

## Quotes about John Playfair

* It was well observed by Playfair, some 90 years ago, that "a theory that explains everything explains nothing."
** Thomas Mellard Reade, in an address of 13 October 1896, published in Proceedings of the Liverpool Geological Society, Volumes 8-9 (1900), p. 28. Reade cited Playfair's statement to Illustrations of the Huttonian Theory of the Earth (1802); it has not yet been located in the volumes of that work presently available online, and was perhaps a summation or paraphrase of his assertions.
* Playfair's judicious use of astronomy was countered by John Bentley with a scriptural argument which will not convince many people today. In 1825, Bentley objected: “By his [= Playfair’s] attempt to uphold the antiquity of Hindu books against absolute facts, he thereby supports all those horrid abuses and impositions found in them, under the pretended sanction of antiquity. Nay, his aim goes still deeper, for by the same means he endeavours to overturn the Mosaic account, and sap the very foundation of our religion: for if we are to believe in the antiquity of Hindu books, as he would wish us, then the Mosaic account is all a fable, or a fiction.”
** John Bentley: Hindu Astronomy, republished by Shri Publ., Delhi 1990, p.xxvii; also discussed by Richard L. Thompson: “World Views: Vedic vs. Western”, The India Times, 31-3-1993. On p.111, we find that Bentley has "proven" that Krishna was born on 7 August in AD 600 (the most conservative estimate elsewhere is the 9th century BC), and on p.158ff., that Varaha Mihira (AD 510-587) was a contemporary of the Moghul emperor Akbar (r.1556-1605). quoted in Elst, Koenraad (1999). Update on the Aryan invasion debate New Delhi: Aditya Prakashan., also in Elst, Koenraad (2007). Asterisk in bharopiyasthan: Minor writings on the Aryan invasion debate.
* One of the earliest estimates of the date of the Vedas was at once among the most scientific. In 1790, the Scottish mathematician John Playfair demonstrated that the starting-date of the astronomical observations recorded in the ephemeris tables still in use among Hindu astrologers (of which three copies had reached Europe between 1687 and 1787) had to be 4300 BC. His proposal was dismissed as absurd or as blasphemous by some, but it has so far not been refuted by any scientist... So, it turns out that the data given by the Brahmins corresponded not with the results deduced from their formulae, but with the actual positions, and this, according to Playfair, for nine different astronomical parameters. This is a bit much to explain away as coincidence or sheer luck.
** Elst, Koenraad (1999). Update on the Aryan invasion debate New Delhi: Aditya Prakashan. also in Elst, Koenraad (2007). Asterisk in bharopiyasthan: Minor writings on the Aryan invasion debate.