In a world in which computer programmers and tech entrepreneurs increasingly control the norms of civil society discourse through social media; and, the borders between science and social science are increasingly blurred for public problems like climate change; it seems to me that the pursuit of philosophy has never been more important for understanding science and technology than it is today. Not only is philosophy of science and technology an intellectually valid and relevant pursuit in its own right, as argued for instance by Michela Massimi, but it is also as a key component in scientists’ education, training and even practice too. I reject, therefore, Feynman’s assertion about the irrelevance of philosophy of science to scientific practice. In a post-truth age, scientists must either be able to explain how they know what they claim to know in broad epistemological terms, or must at least understand and accept the importance of this line of questioning and therefore allow philosophers to unpick and elucidate for a broader audience, scientific claims to privileged knowledge of the world. It is simply no longer satisfactory to draw on all-too-familiar recourse to the ‘Method’ or to (politicised?) scientific consensus. These rationalities are little more than scientism when left as unqualified justifications for scientists’ expert status. Contemporary science is far from the Popperian ideal it is often construed to be.