I argue that much of the success of chemical engineering during the period 1960-1980 was due to the adoption and mastering of mathematical tools, tools that opened horizons and helped define the profession. I argue that a similar opportunity is faced today, and that several tools from the area of complex systems, which we can readily embrace and develop, should be part of the standard toolkit of chemical engineering. I argue that the field is ready for this expansion, and that these tools will expand the core, crosslink domains, and open tip areas where the profession will have much to contribute. (c) 2005 American Institute of Chemical Engineers.