RT Journal Article SR Electronic T1 The turn for ultimate harm: a reply to Fenton JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP 441 OP 444 DO 10.1136/jme.2010.036962 VO 37 IS 7 A1 Ingmar Persson A1 Julian Savulescu YR 2011 UL http://jme.bmj.com/content/37/7/441.abstract AB Elizabeth Fenton has criticised an earlier article by the authors in which the claim was made that, by providing humankind with means of causing its destruction, the advance of science and technology has put it in a perilous condition that might take the development of genetic or biomedical techniques of moral enhancement to get out of. The development of these techniques would, however, require further scientific advances, thus forcing humanity deeper into the danger zone created by modern science. Fenton argues that the benefits of scientific advances are undervalued. The authors believe that the argument rather relies upon attaching a special weight to even very slight risks of major catastrophes, and attempt to vindicate this weighting.