This article defends Richard Titmuss's argument, and Peter Singer's sympathetic support for it, against orthodox philosophical criticism. The article specifies the sense in which a market in blood is "dehumanising" as having to do with a loss of "imagined community" or social "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, in different but interrelated ways, the claim that a market in blood is "imperialistic." Concentrating on the first domino argument the article considers the view that monetary and non-monetary meanings of the same good can co-exist given the robustness of certain kinds of relationship and joint undertakings within which gifts can figure. It argues that societal relationships are vulnerable or permeable to the effects of the market in a way that those constitutive of the personal sphere are not. General, more broadly political questions remain unanswered but the core of Titmuss's original and challenging argument remains and can be presented in a defensible form.