Cartesian separation and enlightenment have led to a widespread conceptual separation of science and technology. Consequently a certain philosophical tradition holds pure science as a metaphysical striving for irrefutable truth that is morally neutral and only ( dirty?) applications as morally accountable. An opposite extreme position holds scientists responsible for everything that is done with their discoveries. Based on an interpretation of science to be a social construct and the observation that moral criteria are the results of social processes the (...) paper demonstrates by the example of synthetic chemistry that science is not an elite end in itself and as such is not free from obligation to moral criteria. The moral responsibility of a scientist, which arises from his professional expertise, is limited to the available knowledge of his discipline. The moral responsibility, which he carries beyond that as responsible acting human, derives from the cultural identity and the normative values under which his action is carried out. This conclusion is illustrated by the examples of DDT, Aspirin and Heroin. (shrink)