At the point of its conception, the SCOT approach was partly motivated by the ideas of the strong programme in the sociology of science (Bloor 1973). In their seminal article, Pinch and Bijker refer to the Principle of Symmetry as the most influential tenet of the Sociology of Science, which should be applied in historical and sociological investigations of technology as well. It is strongly connected to Bloor's theory of social causation.