 An important — and enduring — objection to this argument, however, was raised early on by Max Black (reported in Smart 1959). Black argued, following Frege (1892), that the only way that terms with different meanings can denote the same state is to express different properties, or “modes of presentation” of that state. But this implies, he argued, that if terms like ‘pain’, ‘thought’ and ‘desire’ are not equivalent in meaning to any physicalistic descriptions, they can denote physical states only by expressing irreducibly mental properties of them. Thus, even if ‘pain’ and ‘C-fiber stimulation’ pick out a single type of neural state, this state must have two types of properties, physical and mental, by means of which the identification can be made. This argument has come to be known as the “Distinct Property Argument”, and is taken by its proponents to undermine a thorough-going materialistic theory of the mind. (See White 1986 and 2007, for more recent versions of this argument, and Block 2007, for a response.)