Joseph Sonnenfels was born in Nikolsburg, Moravia (now Mikulov, in the Czech Republic), the son of Lipman Perlin aka Alois Wiener aka von Sonnenfels and grandson of Rabbi Yechiel Hassid. Joseph Sonnenfels was baptised to Christianity during his childhood.
Joseph Sonnenfels was professor of applied political science at the University of Vienna (1763), and succeeded his father as Court interpreter. He was appointed to Aulic Councellor and V.P. of the commision of Judicial Reform (1779). The commission was responsibe for writing the Austrian civil and criminal codes. He was a strong supporter of the abolition of torture and capital punishment, and risked personal hazards for this cause.
Joseph von Sonnenfels was also a famous publicist and wrote in clear, simple and pure juristic language. He formulated the Austrian Civil Code Ober Die Aubschaffung der Folter (1775) and published more than 150 books and pamphlets. His textbooks on economy were very inflentual for years