In scholarly debates, as well as in everyday parlance, we tend to pull science and technology apart: science gives us theory, and technology applies it. In practice, however, science and technologies are highly intertwined. This book sets out to look at the practice of science, and to elucidate the role of technologies and of instruments in the process of knowledge production. In this exercise, it becomes evident that technologies cannot be analyzed on their own, but always in relation to us epistemic agents. Thus, the book pleads for the importance to look at the process of knowledge production in techno-scientific practices, in which there is a triad of relations to look at: us – the instruments – and the world. The book thus builds bridges between Philosophy of Science, Philosophy of Technology, and Science and Technology Studies in an unprecedent way.