In this lecture, Pam Silver describes some of the exciting work her laboratory has carried out in synthetic biology and illustrates how engineers are not only bringing new tools to traditional biology but also a new perspective. Traditional biology has emphasized understanding the causes and mechanisms of biological processes, but bioengineers put that knowledge to practical use. Our progress in understanding life, particularly the detailed molecular biology of cells, coupled with new technologies and computing power, is starting to transform biology from a ‘soft’ science focused on description to a ‘hard’ science focused on quantifying, predicting and controlling its properties. The lecture was given at the 12 May 2009 launch of the Imperial-based Centre for Synthetic Biology and Innovation—established in partnership with the London School of Economics and funded by the Engineering and Physical Sciences Research Council (EPSRC) as part of a science and innovation award.