Selected thoughts and writings by Geoffrey Hewitt

This synopsis depicts selected ideas and the vision of G. Hewitt in relation to nuclear thermal-hydraulics. This task is ambitious and somewhat unrealistic: Geoff worked for half a century and produced several hundred papers and dozens of books. An analytical rather than synthetic work has been completed, considering a dozen selected documents (cited in the list of references) which were co-authored by Geoff. Key statements were extracted from each document. Within the context of these books and papers, these extracts are used to show here the criticism by Geoff of the current state of knowledge and, primarily, his concerns about the capabilities of numerical models. The discussion in the present paper may be of interest to the new generation of scientists in the field of nuclear thermal-hydraulics, by generating critical views when designing experiments or interpreting the outcomes from computational tools and/or models