Technology has been an important influence on the development of education. However, very little research in Educational Technology considers this history, and even less questions it. In this paper, we argue that our understanding of educational technology should be informed by the philosophy of technology -- a field that has attempted to explore what these historical developments mean. This paper focuses on the ontological turn in philosophy and the technological thought of Marx and Heidegger. This is used to propose a foundation that can help researchers rethink educational technology, expanding research to account for human-education, human-technology and education-technology relations. It is proposed that human-education relationships should make students 'become what they are', highlighting their subjectivity rather than concentrating on information. Human-technology relationships can change the focus of design practice, so that technology is not merely seen as an efficient tool, but something 'handy' for peoples' educational needs. Education-technology relationships explain how technology can shape education, and re-introduces the idea of 'techne' as something to be valued in education.