Drago Ibler published a manifest of the group "Earth" in which he wrote: "We should live in the spirit of our age and create accordingly; … The modern life is full of social ideas and questions considering everybody and an artist can’t stand outside that collective because art and life are one." Between 1925 and 1935, he established the so-called "Zagreb school of architecture" with fellow architects Drago Galić, Mladen Kauzlarić, Stjepan Planić and others. From the thirties the works of "Zagreb school" of architecture can stand alongside with the best world architecture. They often merge two opposite directions in the architecture of those days – functionalistic and organic.