STEM – science, technology, engineering, and mathematics – has become ubiquitous in education. How STEM and STEM education are to be defined is still a matter of debate, however, and it is only just recently that STEM education has been probed from a philosophical point of view. The need for a philosophical basis for STEM education is therefore fundamental. The aim of this study is thus to investigate specifically the role of the “T” and “E” in STEM, and how they not only may be fruitfully integrated with the “S” and “M”, as part of a philosophy of STEM education, but also potentially form a methodological backbone of such a philosophy when it comes to design. The research question that underpinned the study is: What are the affordances of Mitcham’s (1994) fourfold philosophical framework of technology for unifying the STEM subjects, with particular consideration of the “T” and “E”? The research methodology consisted of a qualitative meta-synthesis of the literature regarding the philosophy of technology and engineering, technology education, and the current issues of integrating the various STEM subjects. We conclude that from a methodological point of view – Mitcham’s “activity” – the design in technology (“T”) and engineering (“E”) holds the most promising affordances for unifying the four STEM subjects. Design as part of particular design projects may require the “design” of applicable scientific experiments as well as the design of applicable mathematics expressions and formulae specifically when modelling in “E” (and “T”).