What do you mean by "psycho-philosophical case studies"? Why do you think that you need Prolog for this? Are you familiar e.g. with CYC and their way of knowledge formalisation/representation? See e.g https://iral.cs.umbc.edu/Pubs/AAAI06SS-SyntaxAndContentOfCyc... (or the full list of publications https://cyc.com/publications/). CYC is interesting because they have been formalizing knowledge for a very long time, and in parallel have also improved their methods and technologies. Prolog is very rudimentary in comparison. Or did you have a look at e.g. the https://en.wikipedia.org/wiki/Semantic_Web with all the related technologies, such as OWL?