He was a member of the Beirut branch of the Committee of Union and Progress (CUP) (also called the "Young Turks") and knew Yiddish, Arabic, English, French, Hebrew and the "Judaeo-Spanish" dialect spoken by the Sephardim.
Speaking of the Ottoman Empire, Yellin said "The noble Ottoman nation is made up of different groups who live together, who for the sake of homeland [vatan] have shaped themselves into one mass."
[3] Speaking in Beirut in 1909, Yellin said:[3] "In the Ottoman Empire the different peoples are equal to one another and it is not lawful to divide according to race; the Turkish, Arab, Armenian and Jewish elements have mixed one with the other, and all of them are connected together, molded into one shape for the holy vatan.
"Two pamphlets written by Yellin were dedicated in "profound admiration" to the CUP, which had implemented the Ottoman Constitution of 1908.
His conception of Ottoman identity transcended differences of religion, ethnicity and even language.