You wrote:
> Do you know of any books which take Jacob Klein's work forward? It is
> an area I would like to pursue in the near future.
I have two suggestions for you
The Ethics of Geometry by David R. Lachterman, Routledge, 1989
Eidos and Agathon in Plato's REPUBLIC by Robert Williamson
The first is a book, but the second an article which appeared in
Essays in Honor of Jacob Klein, St. John's College Press, 1976
and it re-appeared in some publication or other as one of four essays on
Plato's Republic. If you want advice about how to obtain the Williamson
work, please send an e-mail to me:
Best wishes,
Sam Kutler