[2] During World War II, he was hidden with his sister, Françoise, by a Protestant family in Besançon, who were later honored as Righteous Among the Nations.

[2] He received semikhah in February 1966 and became rabbi of the Union Libérale Israélite de France from 1967 to 1977, succeeding André Zaoui.

[2] On 2 June 1977, Farhi founded the Liberal Jewish Movement of France with Roger Benarosh and Colette Kessler [fr].

He strongly defended the idea that Halakha (Jewish law), must continue to be amended to keep up with societal changes so that the return of the Sanhedrin can be appropriately applied to modern times.

In 1990, Farhi became involved with La Paix maintenant [fr] and, in January 2010, founded the Centre Culturel Judéo-Espagnol/Al Syete, an association which brought together different Judeo-Spanish organizations.