In 1966, he obtained a master's degree in philosophy and a degree in French literature and civilization. During the next four years, he taught at the French school in Compiègne in 1967 and obtained a DES in Philosophy and a degree in Ancient Greece. From 1971 to 1977 he taught philosophy in secondary schools in Tunisia and at the, before becoming director of a publishing company specializing in books for young people between 1984 and 1987. He was also a reporter of the journal La Presse de Tunisie between 1975 and 1983. Based in Paris in 1988, he obtained a DEA in the Greek language and civilization from the University of Paris III: Sorbonne Nouvelle and a doctorate at the École des hautes études en sciences sociales. He lectured there and also in modern Islamic philosophy at the Sorbonne from 1995 to 1996. Seddik has published many books and translations based on Ancient Greece and Islamic heritage, including works related to the Prophet Muhammad, Imam Ali, and the Qur'an. He also attempted to publish a Qur'an in the form of seven volumes of comics, but was halted after objections from the Tunisian religious authorities in 1992. In 1999 he published a book entitled Brins de chicane. La vie quotidienne à Bagdad au Xe siècle about daily life in Baghdad in the tenth century. His book, Nous n'avons jamais lu le Coran, released in September 2004 explores the language and symbols that are present in the Koran. In the book the author begins with the questioning of the politics of Islam and the role of God. He also directed documentaries including a series of five episodes on Muhammad.
Publications
Éloge du commerce, ed. MédiaCom, Tunis, 1994
Penser l'économique, éd. MédiaCom, Tunis, 1995
L’Abaissé. Première somme de la jurisprudence islamique, ed. MédiaCom, Tunis, 1996
Épîtres d’Avicenne et de Bryson, ed. MédiaCom, Tunis, 1996
Dictionnaire historique de la pensée économique arabe et musulmane, ed. MédiaCom, Tunis, 1998
Brins de chicane. La vie quotidienne à Bagdad au Xe siècle, ed. Actes Sud, Arles, 1999
De l'interprétation des rêves, éd. Al-Bouraq, Beyrouth, 1999
Dits de l'imam Ali, ed. Actes Sud, Arles, 2000
Le Coran : autre lecture, autre traduction, ed. L'Aube, La Tour d'Aigues, 2002
Dits du prophète Muhammad, ed. Actes Sud, Arles, 2002
L'arrivant du soir : cet islam de lumière qui peine à devenir, ed. L'Aube, La Tour d'Aigues, 2004
Nous n'avons jamais lu le Coran, ed. L'Aube, La Tour d'Aigues, 2004
Qui sont les barbares ? : Itinéraire d'un penseur d'islam, ed. L'Aube, La Tour d'Aigues, 2007
Le Grand malentendu. L'Occident face au Coran, ed. L'Aube, La Tour d'Aigues, 2010
Unissons-nous ! Des révolutions arabes aux indignés, ed. L'Aube, La Tour d'Aigues, 2011
Tunisie, la Révolution inachevée, ed. L'Aube, La Tour d'Aigues, 2014
Ce que le Coran doit à la Bible : un dialogue contemporain sur l'islam et le judaïsme, Paris, La Découverte, 2018
