Jacques Rousseau (1683, Geneva - 1753, Isfahan) was a Swiss watchmaker.
 He was sent on a diplomatic mission to Isfahan in Persia (now Iran) by Louis XIV of France in 1708.
 There he became jeweler to Shah Husayn of Persia at around the same time as his first cousin Isaac Rousseau (father of the writer and philosopher Jean-Jacques Rousseau) was jeweler-clockmaker to the Ottoman Sultan Ahmed III in Constantinople (1705-1711).
 Jacques died in Isfahan, where his tombstone is in the Christian (Armenian) Cemetery.
Emmanuel Levinas (] ; 12 January 1906 – 25 December 1995) was a French philosopher of Lithuanian Jewish ancestry who is known for his work related to Jewish philosophy, existentialism, ethics, Phenomenology and ontology.
Eugen D. Relgis (backward reading of Eisig D. Sigler; first name also Eugenio, Eugène or Eugene, last name also Siegler or Siegler Watchel; (22 March 1895 – 24 May 1987) was a Romanian writer, pacifist philosopher and anarchist militant, known as a theorist of humanitarianism.
 His internationalist dogma, with distinct echoes from Judaism and Jewish ethics, was first shaped during World War I, when Relgis was a conscientious objector.
 Infused with anarcho-pacifism and socialism, it provided Relgis with an international profile, and earned him the support of pacifists such as Romain Rolland, Stefan Zweig and Albert Einstein.
 Another, more controversial, aspect of Relgis' philosophy was his support for eugenics, which centered on the compulsory sterilization of "degenerates".
 The latter proposal was voiced by several of Relgis' essays and sociological tracts.
Hans Kelsen (] ; October 11, 1881 – April 19, 1973) was an Austrian jurist, legal philosopher and political philosopher.
 Due to the rise of Nazism in Germany and Austria, Kelsen left his university post because of his Jewish ancestry, and departed to Geneva in 1933, and then to the United States in 1940.
 In 1934, Roscoe Pound lauded Kelsen as “undoubtedly the leading jurist of the time.”
 While in Vienna, Kelsen was a young colleague of Sigmund Freud and wrote on the subject of social psychology and sociology.
Adam Rolland of Gask FRSE (1734-1819) was a Scottish judge and philanthropist.
 He was co-founder of the Royal Society of Edinburgh, personal friend of Lord Melbourne and the basis of the character of "Paul Pleydell" in the novel Guy Mannering by Sir Walter Scott.
Joseph Tanke (Ph.D.
, Boston College; born 1978) is an American philosopher and Associate Professor of Philosophy at the University of Hawaii at Manoa.
 His work focuses on Continental philosophy, the history of philosophy, aesthetics, art theory, and historical ontology.
 Tanke is known for his analysis of major figures in the French philosophical tradition, such as Michel Foucault and Jacques Rancière.
 His book Foucault's Philosophy of Art: A Genealogy of Modernity is one of the first systematic presentations of Michel Foucault's writings on visual art.
 Tanke is the first scholar to publish a comprehensive critical introduction to the thought of Jacques Rancière.
Jacques Maritain (18 November 1882 – 28 April 1973) was a French Catholic philosopher.
 Raised Protestant, he was agnostic before converting to Catholicism in 1906.
 An author of more than 60 books, he helped to revive St. Thomas Aquinas for modern times, and was influential in the development and drafting of the Universal Declaration of Human Rights.
 Blessed Pope Paul VI presented his "Message to Men of Thought and of Science" at the close of Vatican II to Maritain, his long-time friend and mentor.
 The same pope had seriously considered making him a lay Cardinal, but Maritain rejected it.
 Maritain's interest and works spanned many aspects of philosophy, including aesthetics, political theory, philosophy of science, metaphysics, the nature of education, liturgy and ecclesiology.
Malwida von Meysenbug (28 October 1816 — 23 April 1903) was a German writer, her work including "Memories of an Idealist", the first volume of which she published anonymously in 1869.
 As well, she was a friend of Friedrich Nietzsche and Richard Wagner, and met the French writer Romain Rolland in Rome in 1890.
The Romain Rolland Library, earlier known as Bibliothèque Publique, is one of the oldest Libraries of India located in the union territory of Puducherry.
 In the year 1966 when the birth centenary of the Great French Scholar, Romain Rolland who was also a contemporary and a close friend of Mahatma Gandhi was celebrated, the Library was renamed after him and ever since it is known as ‘Romain Rolland Library’.
Jacques Rolland (14 October 1914, Paris – 11 September 1999) was a French politician.
 He represented the Radical Party in the National Assembly from 1956 to 1958.
 Rolland was a friend of Emmanuel Levinas, introduced through a mutual acquaintance, the medievalist Bruno Roy; he wrote an introductory essay to the 1982 publication of Levinas's "De l'évasion", entitled "Getting Out of Being by a New Path".

Question: Jacques Rolland was a friend of a philosopher of which ancestry ?
Answer: Lithuanian Jewish