This article defends Richard Titmuss''s argument, and PeterSinger''s sympathetic support for it, against orthodoxphilosophical criticism. The article specifies thesense in which a market in blood is ``dehumanising'''' ashaving to do with a loss of ``imagined community'''' orsocial ``integration'''', and not with a loss of valued or``deeper'''' liberty. It separates two ``domino arguments''''– the ``contamination of meaning'''' argument and the``erosion of motivation'''' argument which support, indifferent but interrelated ways, the claim that amarket in blood is ``imperialistic.'''' Concentrating onthe first domino argument (...) the article considers theview that monetary and non-monetary meanings of thesame good can co-exist given the robustness of certainkinds of relationship and joint undertakings withinwhich gifts can figure. It argues that societalrelationships are vulnerable or permeable to theeffects of the market in a way that those constitutiveof the personal sphere are not.General, more broadly political questions remainunanswered but the core of Titmuss''s original andchallenging argument remains and can be presented ina defensible form. (shrink)