RT Journal Article SR Electronic T1 The ethical force of definitions. JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP 16 OP 18 DO 10.1136/jme.6.1.16 VO 6 IS 1 A1 D N Walton YR 1980 UL http://jme.bmj.com/content/6/1/16.abstract AB