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.