Joseph Freiherr von Sonnenfels (1732 – 25 April 1817) was an Austrian and German jurist and novelist. He was among the leaders of the Illuminati movement in Austria, and a close friend and patron of Mozart. He is also the dedicatee of Ludwig van Beethoven's Piano Sonata No. 15, Op. 28, which was published in 1801.

He was born in Nikolsburg/Mikulov, Moravia, a son of Perlin Lipmann (1705–1768), chief rabbi of Brandenburg. Perlin Lipmann and his children converted to Catholicism some time between 1735–1741.^[1] Joseph, who was baptized in his early youth, received his elementary education at the gymnasium of his native town Nikolsburg, and then studied philosophy at the University of Vienna. In 1749, he joined the regiment "Deutschmeister" as a private, advancing to the rank of corporal. On his discharge in 1754, he took a course in law at the University of Vienna and established himself as a counselor at law in the Austrian capital. From 1761 to 1763, he officiated as secretary of the Austrian "Arcierengarde". In 1763, he was appointed professor of political science at the University of Vienna, twice acting as rector magnificus. In 1779, he received the title of "Wirklicher Hofrath", and was in 1810 elected president of the Academy of Sciences, a position which he held until his death in Vienna.

From 1765 to 1767 and from 1769 to 1775 Sonnenfels was editor of "Der Mann ohne Vorurtheil", in which paper he defended the liberal tendencies in literature. He improved the Vienna stage especially through his critical work Briefe über die Wienerische Schaubühne, in which he attacked the harlequin of the Vienna theater, causing this figure to be eliminated from the personnel of the stage.

He was chiefly instrumental in bringing about the abolition of torture in Austria (1776). Sonnenfels' attitude toward Lessing placed the former in a very unfavorable light, as it was due to his intrigues and jealousy that Lessing was not called to Vienna. Sonnenfels was severely condemned for his action in this affair. In 1817, Sonnenfels was elected a member of the American Philosophical Society in Philadelphia.^[2]

• Specimen Juris Germanici de Remediis Juris, Juri Romano Incognitis, Vienna, 1757.
• Ankündigung einer Teutschen Gesellschaft in Wien, Vienna 1761.
• Betrachtungen über die neun politischen Handlungsgrundsätze der Engländer (in German). Wien: Georg Ludwig Schulz. 1764.
• Grundsätze der Polizei, Handlung und Finanzwissenschaft, Vienna 1765–67 (8th ed. 1819).
  • Sätze aus der Polizei, Handlungs- und Finanz-Wissenschaft (in German). Vol. 1. Wien: Johann Thomas von Trattner. 1765.
  • Grundsätze der Polizei-Handlung und Finanz (in German). Tübingen: Christian Friedrich Osiander. 1820.
• Briefe über die Wienerische Schaubühne, Vienna 1768 (reedited by Sauer, Vienna 1884).
• Von der Verwandlung der Domänen in Bauerngüter, Vienna 1773.
• Über die Abschaffung der Tortur (in German). Zurich. 1775.
  • Su l'abolizione della tortura (in Italian). Milano: Giuseppe Galeazzi. 1776.
  • Über die Abschaffung der Tortur (in German) (2 ed.). Wien und Nürnberg: C. Weigel & Adam Gottlieb Schneider. 1782.
• Gründet sich das Recht der Monarchen mit dem Tode zu straffen in der Uebertragung der Menschen (in German). Wien: Grund. 1780.
• Erste Vorlesung in diesem akademischen Jahrgange (in German). Wien: Joseph von Kurzbeck. 1782.
• Abhandlung über die Aufhebung der Wuchergesetze, Vienna, 1791.
• Riflessioni d'un patriotta austriaco ad un amico (in Italian). Wien: Mathias Andreas Schmidt. 1793.
• Handbuch der inneren Staatsverwaltung mit Rücksicht aus die Umstände und Begriff der Zeit (in German). Wien: Joseph Camesina & C. 1798.
• Ueber die Stimmenmehrheit bei Criminalurtheilen, Vienna, 1801.
  • Über die Stimmenmehrheit bei Kriminal-Urtheilen (in German) (2 ed.). Wien: Camesina. 1808.

His Gesammelte Werke appeared in 10 volumes (Vienna, 1783–87), and contained most of his belletristic works, poems, and dramas.

• 
  Der Mann ohne Vorurtheil, 1765
• 
  Erste Vorlesung in diesem akademischen Jahrgange, 1782

•  This article incorporates text from a publication now in the public domain: Isidore Singer and Frederick T. Haneman (1901–1906). "Sonnenfels". In Singer, Isidore; et al. (eds.). The Jewish Encyclopedia. New York: Funk & Wagnalls.
• The Masonic Thread of Mozart by Katherine Thomson (page 16). Published in London 1977.

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German Wikisource has original text related to this article:

Joseph von Sonnenfels

• Literature by and about Joseph von Sonnenfels in the German National Library catalogue
• Works by and about Joseph von Sonnenfels in the Deutsche Digitale Bibliothek (German Digital Library)
• Joseph von Sonnenfels in Austria-Forum (in German) (at AEIOU)

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