In 1924, a new, different wave of aliyah began - the Fourth Aliyah - and tens of thousands of Jews from Poland streamed into Palestine. Most of them were not pioneers but middle-class Jews interested in urban rather than agricultural settlement. Over the next two years, Tel Aviv grew considerably, and turned from a town into a city. The Fourth Aliyah clarified the ongoing argument: should the World Zionist Organization support agricultural and cooperative settlement, which obliged it to make large financial investments, or should it leave the market forces "to play themselves out," with the minimum of interference, so as to enable the growth of a capitalistic market? There were many who objected to this, the most prominent being Dr. Chaim Weizmann.