The call for the integration of ethical considerations in the teaching of science is now firmly on the agenda. Taking as illustrative a science lesson in a pre-service teacher class, the authors consider the roles of STSE (science, technology, society and environment) and the increasingly influential heavily funded STEM (science, technology, engineering and mathematics) education initiatives. The origins and foci of both initiatives are discussed, as are their disparate ontological foundations. The use of Habermas' knowledge theories in conjunction with ethical frameworks is posited as a way of considering both STSE and STEM perspectives and their implications for strengthening science pedagogy.