We have aimed to write a book that speaks to multiple audiences, starting from the proposition that a synoptic view of the scientific imagination in South Africa over 300 years has much to offer specialist as well as general readerships. Firstly, for those interested primarily in South Africa, our argument is that scientific ideas and practices have irreversibly shaped society, and that they should be understood as an intrinsic element of political power, economic growth, and social change. In spheres from human and veterinary medicine to mining and agriculture, from the technologies of transport to those of water and energy, science has distinctively moulded South Africa’s modernity. It has done so directly through the exercise of techno- and bio-power – and also indirectly through theories and rhetorics of exclusion and inclusion, progress and entitlement, regeneration and degeneration.