View source for Louis Bertrand Castel

{{Short description|Mathematician, philosopher}}
{{EngvarB|date=July 2017}}
{{Use dmy dates|date=November 2023}}
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'''Louis Bertrand Castel''' (5 November 1688<ref name="Schier">{{cite book|last1=Schier|first1=Donald Stephen|title=Louis Bertrand Castel, anti-Newtonian scientist|date=1941|publisher=The Torch press|location=Cedar Rapids, Iowa|page=3|url=https://babel.hathitrust.org/cgi/pt?q1=born;id=uc1.%24b36247;view=image;seq=23;start=1;sz=10;page=root;num=3;size=100;orient=0|accessdate=28 November 2016|quote="Louis-Bertrand Castel, second son of Guillaume Castel, physician, and of his wife, Louise, was born at Montpellier on the fifth of November, 1688. Footnote: And not on the eleventh as stated in the eulogy of Castel, Journal de Trevoux, April 1757, p. 1100. The fifth is the date given in the parish records of the church of Notre Dame in Montpellier. These records are now in the municipal archives."}}</ref><ref name="Kipnis">{{cite book|last1=Kipnis|first1=Igor|title=Harpsichord and clavichord : an encyclopedia|date=2006|publisher=Routledge|location=New York|isbn=0415937655|url=https://books.google.com/books?id=LG3DUo0pBckC&pg=PA57}}</ref> – 11 January 1757<ref name="Schier2">{{cite book|last1=Schier|first1=Donald Stephen|title=Louis Bertrand Castel, anti-Newtonian scientist|date=1941|publisher=The Torch press|location=Cedar Rapids, Iowa|page=57|url=https://babel.hathitrust.org/cgi/pt?q1=1757;id=uc1.%24b36247;view=image;seq=77;num=57;start=1;sz=10;page=root;size=100;orient=0|accessdate=28 November 2016|quote="He died on the eleventh of January, 1757. Footnote: This is the date given in his eulogy in the ''J. de T.'', April, 1757, pp. 1114–1115. Other dates given are the ninth and the twelfth. See ''J. de T.'', January, 1759, p. 357."}}</ref><ref name="Richard">{{cite book|last1=Richard|first1=Jean-Olivier|title=The Art of Making Rain and Fair Weather: The Life and World System of Louis-Bertrand Castel, SJ (1688–1757)|date=2015|publisher=Johns Hopkins University|location=Baltimore, Maryland|page=1|url=https://www.academia.edu/21061783|accessdate=28 November 2016}}</ref>) was a French mathematician born in [[Montpellier]], who entered the order of the [[Jesuits]] in 1703. Having studied literature, he afterwards devoted himself entirely to mathematics and natural philosophy. After moving from [[Toulouse]] to Paris in 1720,<ref name="Rose">{{cite book | title = A New General Biographical Dictionary | first = Hugh James |last= Rose | publisher = London: B. Fellowes, &c | year = 1857 | url = https://archive.org/details/anewgeneralbiog08rosegoog | page = [https://archive.org/details/anewgeneralbiog08rosegoog/page/n115 107] }}</ref> at the behest of [[Bernard de Fontenelle]], Castel acted as the science editor of the Jesuit ''[[Journal de Trévoux]]''.<ref name="Hankins">{{cite journal|last1=Hankins|first1=Thomas L.|title=The Ocular Harpsichord of Louis-Bertrand Castel; Or, The Instrument That Wasn't|journal=Osiris|year=1994|volume=9|issue=Instruments|pages=141–156|jstor=302003|doi=10.1086/368734|s2cid=144882388}}</ref>

He wrote several scientific works, that which attracted most attention at the time being his {{lang|fr|Optique des couleurs}} (1740), or treatise on the melody of colours. He also wrote {{lang|fr|Traité de physique sur la pesanteur universelle des corps}} (1724), {{lang|fr|Mathématique universelle}} (1728), and a critical account of the system of [[Sir Isaac Newton]] in 1743.

==Philosophical approach==
Castel wrote on areas as wide-ranging as physics, mathematics, morals, aesthetics, theology and history. His philosophical approach attempted to reconcile fields and viewpoints. Castel based much of his work on [[Analogy|analogical thinking]], seeking to understand the physical and moral worlds through the discovery of analogies.<ref name="Richard"/>

Castel's first major published work was his ''Traité de physique de la pesanteur universelle des corps'' (1724). He first attempted to systematise physical phenomena, through the mechanical action of universal gravity. He then considered a mechanistic world-view's shortcomings, from a theological and metaphysical perspective. He held humanity as central to natural philosophy, in that humans are embodied spirits whose actions, chosen with [[free will]], affect the world around them and each other. In emphasising free will and the actions of mankind Castel attempted to counter [[determinism|deterministic]] views of man and nature.<ref name="Richard"/>

Castel considered that true science should focus on readily experienced and described phenomena. His emphasis on the description and analysis of the perceived world was consistent with analogic thinking and phenomenal explanation. Castel actively opposed the idea of a science based on experimental methods, instruments, speculation and theorising.<ref name="Richard"/>

== The Ocular Harpsichord ==
[[File:A caricature of Louis-Bertrand Castel's "ocular organ".jpg|thumb|right|200px|A caricature of Louis-Bertrand Castel's "ocular organ" by [[Charles Germain de Saint Aubin]]]]

Early on, Castel illustrated his optical theories with a proposal for a ''Clavecin pour les yeux'' (''Ocular Harpsichord'', 1725). A new series of articles, published in the ''Mercure de France'' in 1735, gave his idea wider currency.<ref name="Franssen">{{cite journal|last1=Franssen|first1=Maarten|title=The Ocular Harpsichord of Louis-Bertrand Castel|journal=Tractrix|year=1991|volume=3|page=39|url=http://www.tbm.tudelft.nl/CastelOcularHarpsichord|accessdate=28 November 2016}}</ref> In 1739 the German composer [[Georg Philipp Telemann|Telemann]] went to France to see Castel's Ocular Harpsichord for himself. He ended up composing several pieces for it, as well as writing a description of it.<ref>''Descriptions of an Eye-Organ or the Eye-Harpsichord Invented by the Famous Herr Pater Castel'', 1739, as cited by {{citation|title=Harmony and Dissent: Film and Avant-garde Art Movements in the Early Twentieth Century|volume=3|series=Film and Media Studies|first=R. Bruce|last=Elder|publisher=Wilfrid Laurier Univ. Press|year=2008|isbn=9781554580286 |page=54|url=https://books.google.com/books?id=gJ408vKWZ14C&pg=PA54}}.</ref>

The ocular harpsichord had sixty small coloured glass panes, each with a curtain that opened when a key was struck. A second, improved model of the harpsichord was demonstrated for a small audience in December 1754. Pressing a key caused a small shaft to open, in turn allowing light to shine through a piece of stained glass.<ref>{{cite web|title=Color and Music|url=http://www.musictheory21.com/jae-sung/syllabus/graduate/rameau-studies/2002-1/documents/color-and-music.pdf|website=Music Theory 21|accessdate=28 November 2016}}</ref><ref name="McDonnell">{{cite web|last1=McDonnell|first1=Maura|title=Visual music|url=http://homepage.eircom.net/~musima/visualmusic/visualmusic.htm|website=Colour and Sound|year=2002}}</ref> Castel thought of colour-music as akin to the lost language of paradise, where all men spoke alike, and he claimed that thanks to his instrument's capacity to paint sounds, even a deaf listener could enjoy music.<ref name="Peel">{{cite journal|last1=Peel|first1=James|title=The Scale and the Spectrum|journal=[[Cabinet (magazine)|Cabinet]]|year=2006|volume=Winter|issue=22|url=http://cabinetmagazine.org/issues/22/peel.php|accessdate=28 November 2016}}</ref>
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== Criticism of Newton ==
[[Image:Castel L'Optique des couleurs 1740.jpg|right|thumb|200px|Castel's 1740 comparison of Newton's spectral colour description with his explanation in terms of the interaction of light and dark, which Goethe later developed into his [[Theory of Colours]]. ]]

[[File:Castel, Louis – Mathématique universelle abregée à l'usage et à la portée de tout le monde, 1728 – BEIC 94382.jpg|thumb|''Mathématique universelle abregée à l'usage et à la portée de tout le monde'', 1728]]

It was in 1740 that Louis Bertrand Castel published a criticism of Newton's spectral description of prismatic colour<ref name="Castel">{{cite book | title = L'Optique des couleurs | publisher = Paris | year = 1740 | first = Louis-Bertrand |last= Castel|url=https://archive.org/details/gri_c00033125008507283}}</ref> in which he observed that the colours of white light split by a prism depended on the distance from the prism, and that Newton was looking at a special case. It was an argument that [[Goethe]] later developed in his [[Theory of Colours]].<ref name="Silverman">{{cite book | title = Instruments and the Imagination | first1 = Thomas L. |last1=Hankins |first2= Robert J. |last2=Silverman | publisher = Princeton University Press | year = 1995 | isbn = 0-691-00549-4 | url = https://books.google.com/books?id=O9e_7E22caAC&pg=PA250 }}</ref><ref name="MacTutor">{{MacTutor Biography|id=Castel}}</ref>

== See also ==
* [[Color organ]]

==References==
{{reflist}}
*{{EB1911|wstitle=Castel, Louis Bertrand}}

== External links ==
* [https://books.google.com/books?id=qWRpa2o77ZYC&pg=PA234-IA2 "Musique Oculaire" in Edmé-Gilles Guyot, ''Nouvelles récréations physiques et mathématiques'', Gueffier, Paris 1770, pp. 234–240.]

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{{DEFAULTSORT:Castel, Louis Bertrand}}
[[Category:French mathematicians]]
[[Category:1688 births]]
[[Category:1757 deaths]]
[[Category:18th-century French Jesuits]]
[[Category:Visual music artists]]
[[Category:Fellows of the Royal Society]]
[[Category:Catholic clergy scientists]]
[[Category:Jesuit scientists]]