TEHRAN, Nov. 17 (MNA) – World Philosophy Day, with the theme of wisdom and spirituality, was held at Iranian Institute of Philosophy (IRIP) on Monday. World Philosophy Day, on November 19 in 2015, was proclaimed by UNESCO to be celebrated every 3rd Thursday of November. Celebrating the day, UNESCO underlines the enduring value of philosophy for the development of human thought, for each culture and for each individual.