Complex sentence: A philosopher of the Renaissance, Pico della Mirandola, in his'Oration on the Dignity of Man', spoke in front of hostile clerics of the dignity of the liberal arts and of the dignity and glory of angels.
Split into simpler sentences: A philosopher of the Renaissance, Pico della Mirandola, found dignity in ideas and in beings. In his "Oration on the Dignity of Man", he told hostile clerics about the dignity of the liberal arts and about the dignity and the glory of angels.