Laura, I recall reading a piece by Julian Savulescu in 2002 on the future of value argument.. Abortion, Embryo Destruction and the Future of Value Argument JME 28, 133-135. It is a short piece that likely does not supply as much argument as you are looking for, but there may be some helpful references there. Best, Kyle Kyle Anstey PhD Candidate Centre for Apllied Philosophy and Public Ethics Department of Philosophy, The University of Melbourne Australia 3010 http://www.student.unimelb.edu.au/~kwanstey/