One specific strand of this discussion emerged from consideration of Weber’s (2005) argument that biology is heteronymous, i.e., that it ultimately borrows its explanatory power from the laws of physics and chemistry. Weber uses Hodgkin and Huxley’s model of the action potential as an exemplar of the reducing biological phenomena to physical laws (such as Ohm’s law and the Nernst equation). Craver (2006) responds that the explanatory force of Hodgkin and Huxley’s model, in fact, requires a grasp of the distinctly biological properties of ion channels, which properties were black-boxed in Hodgkin and Huxley’s total current equation (see also Craver 2007; Bogen 2008b; Weber 2008).