maybe you wish to consult http://socserv.mcmaster.ca/~econ/ugcm/3ll3/obrien/mediaeval.pdf http://www.newadvent.org/cathen/index.html and M. Blaug (ed). St. Thomas Aquinas (1225-1274) Elgar 1991 I trust you are familiar with http://socserv2.socsci.mcmaster.ca/~econ/ugcm/3ll3/ http://gallica.bnf.fr Nicholas J. Theocarakis