 Together with Shantena Augusto Sabbadini (b.1943), the Italian physicist and spiritual thinker, he produced the first Italian rendering of the "I Ching" based directly on the Chinese original.Ritsema was born at Velp near Rheden in the Netherlands to the family of Ipo Christiaan Ritsema, whose ancestors hailed from Friesland, and his wife Frances Johanna, "née" Van den Berg, who was partly of Frisian, partly of British and Huguenot origin.