   In essence, the information-theoretic proposal is that device S carries information about instantiations of property G if and only if S’s being F is nomically correlated with instantiations of G. If S would not be F unless property G were instantiated, then S’s being F carries information about, or as Dretske likes to say, indicates G-ness. A fingerprint carries information about the identity of the human being whose finger was imprinted. Spots on a human face carry information about a disease. The height of the column of mercury in a thermometer carries information about the temperature. A gas-gauge on the dashboard of a car carries information about the amount of fuel in the car tank. The position of a needle in a galvanometer carries information about the flow of electric current. A compass carries information about the location of the North pole. In all such cases, a property of a physical device nomically covaries with some physical property instantiated in its environment (for critical discussion of the informational program, see Kistler 2000, Loewer 1987, 1998 and Putnam 1986).