The legal and moral issues that synthetic biology (SB) and its medical applications are likely to raise with regard to intellectual property (IP) and patenting are best approached through the lens of a theoretical framework highlighting the ‘‘co-construction’’ or ‘‘co-evolution’’ of patent law and technology. The current situation is characterized by a major contest between the so-called IP frame and the access-to-knowledge frame. In SB this contest is found in the contrasting approaches of Craig Venter’s chassis school and the BioBricks school. The stakes in this contest are high as issues of global health and global justice are implied. Patents are not simply to be seen as neutral incentives, but must also be judged on their effects for access to essential medicines, a more balanced pattern of innovation and the widest possible social participation in innovative activity. We need moral imagination to design new institutional systems and new ways of practising SB that meet the new demands of global justice.